1994
Project Title - Comparative pharmacology of fluconazole in three psittacine species
Investigator - Keven Flammer
Institution - North Carolina State University College of Veterinary Medicine
Link - http://www.cvm.ncsu.edu/docs/personnel/flammer_keven.html
Publication(s)
Flammer K, Papich M. Pharmacokinetics of fluconazole after oral administration of single and multiple doses in African grey parrots. American Journal of Veterinary Research 67(3): 417-422, 2006.
Abstract - Objective - To determine the pharmacokinetics and effects of orally administered fluconazole in African grey parrots. Animals - 40 clinically normal Timneh African grey parrots (Psittacus erithacus timneh). Procedure - In single-dose trials, parrots were placed into groups of 4 to 5 birds each and fluconazole was administered orally at 10 and 20 mg/kg. Blood samples for determination of plasma fluconazole concentrations were collected from each group at 2 or 3 of the following time points: 1, 3, 6, 9, 12, 24, 31, 48, and 72 hours. In multiple-dose trials, fluconazole was administered orally to groups of 5 birds each at doses of 10 and 20 mg/kg every 48 hours for 12 days. Trough plasma concentrations were measured 3 times during treatment. Groups receiving 20 mg/kg were monitored for changes in plasma biochemical analytes, and blood samples were collected on days 1 and 13 of treatment to allow comparison of terminal half-life. Results - Peak plasma concentrations of fluconazole were 7.45 and 18.59 µg/mL, and elimination half-lives were 9.22 and 10.19 hours for oral administration of 10 and 20 mg/kg, respectively. Oral administration of fluconazole for 12 days at 10 or 20 mg/kg every 48 hours did not cause identifiable adverse effects or change the disposition of fluconazole. Conclusions and Clinical Relevance - Oral administration of fluconazole to parrots at 10 to 20 mg/kg every 24 to 48 hours maintains plasma concentrations above the minimum inhibitory concentration for several common yeast species. The prolonged dosing interval is an advantage of this treatment regimen.
Importance to Avian Medicine – Fluconazole is a fungistatic triazole antifungal agent used for the treatment of yeast and fungal infections in birds. This study was conducted to determine the plasma concentrations of the drug in Timneh African grey parrots at after oral administration of two different dosages, in order to better determine appropriate dosage and frequency for this drug. It was found that dosing at 10 to 20 mg/kg every 24 to 48 hours achieved plasma concentrations that were above the concentration believed to be effective against common yeast species.
1994
Project Title - Evaluation of hetastarch for the management of hypoproteinemia and hypovolemia in chronically debilitated birds
Investigator - Marc Raffe
Institution - University of Minnesota
Importance to Avian Medicine – Hetastarch is a synthetic polymer that acts as a plasma volume expander by increasing the oncotic pressure in the extracellular space. It is most often used in the critically ill patient to rapidly restore fluid volume and blood pressure and may be very effective for this use in birds. However, there is little published information on the efficacy and safety of hetastarch in birds.
1995
Project Title - Autologous, homologous and heterologous blood transfusions in avian species
Investigator - Laurel Degernes
Institution - North Carolina State University College of Veterinary Medicine
Link - http://www.cvm.ncsu.edu/docs/personnel/degernes_laurel.html
Publication(s)
Degernes LA, Crosier ML, Harrison LD, Dennis PM, Diaz DE. Autologous, homologous, and heterologous red blood cell transfusions in cockatiels (Nymphicus hollandicus). Journal of Avian Medicine and Surgery 13(1): 2-9, 1999.
Abstract - The survival of fluorescent-labelled red blood cells (RBCs) after single and multiple transfusions in compatible cross-matched groups of birds was investigated in groups of 5 cockatiels (Nymphicus hollandicus): an autologous or control group (transfusion to same bird); a homologous group (cockatiel to cockatiel), a heterologous group of 2 species in the same taxonomic family (blue-fronted Amazon parrot [Amazona aestiva] to cockatiel), and a heterologous group of 2 species in different orders (pigeon [i] to cockatiel). Donor blood (1 ml) was centrifuged and the plasma discarded. The washed RBCs were stained with a fluorescent dye and transfused into recipient cockatiels. Three RBC transfusions using the same donor-recipient pairs were administered at 0, 7, and 9 weeks, and then serial blood samples were examined by flow cytometry to measure fluorescent-labelled RBCs in circulation over time. The fluorescent-labelled RBC half-life was significantly longer in the autologous and homologous groups (range, 10.5 to 16.8 days) than in the 2 heterologous groups (range, 0.1 to 2.6 days) after all 3 transfusions (P < .001 for all comparisons). There was no difference in half-life of RBCs between the 2 heterologous groups after any of the transfusions or between the autologous and homologous groups after transfusions 1 and 2. After transfusion 3, the half-life was longer in the autologous group than in the homologous group (P < .001). It is concluded that fluorescent-labelled RBC survival is comparable after autologous and homologous avian transfusions; however, heterologous transfusions result in significantly shorter half-life of transfused RBCs, regardless of taxonomic relatedness. Therefore, heterologous transfusions in birds may not be efficacious.
Importance to Avian Medicine – Blood transfusions are widely used in the critical care setting to treat blood loss and other causes of anemia. However, the length survival of transfused red blood cells in psittacines (parrots and parrot-like birds) is not known. This study was conducted to determine the length of survival of red blood cells in cockatiels after transfusion. Three types of transfusions were performed – transfusion of the host cockatiel’s own blood (autologous), a cockatiel-to-cockatiel transfusion (homologous), and an Amazon parrot to cockatiel (heterologous) transfusion. The study found that red blood cell survival was far less after a heterologous blood transfusion (0.1 to 2.6 day half-life) than after an autologous or homologous transfusion (10.5 to 16.8 day half-life). The authors warned that heterologous transfusions may not be effective for long in birds.
1995
Project Title - Improved detection method for Mycobacterium avium infection in birds
Investigator - Inge Eriks
Institution - Washington State University
Publications
Mendenhall MK, Ford SL, Emerson CL, Wells RA, Gines LG, Eriks IS. Detection and differentiation of Mycobacterium avium and Mycobacterium genavense by polymerase chain reaction and restriction enzyme digestion analysis. Journal of Veterinary Diagnostic Investigation 12(1): 57-60, 2000.
Abstract - The experiments described here using PCR amplification and restriction enzyme digestion of a portion of the hsp65 gene offer a rapid and simple assay for the detection of and distinction between M. avium and M. genavense.
Importance to Avian Medicine – Mycobacteriosis is a serious disease that affects a wide array of avian species. The diagnosis of mycobacteriosis can be extremely challenging. Several different species of Mycobacteria can infect birds, including M. avium and M. genevense, and the clinical implications and zoonotic risk to humans can be different between mycobacterial species. This study was conducted to develop a diagnostic method (PCR) to detect and differentiate M. avium from M. genavense.
1995
Project Title - Analgesic effects of butorphanol and buprenorphine for the psittacine bird
Investigator - Joanne Paul-Murphy
Institution - University of Wisconsin (current address: University of California at Davis)
Link - http://www.vetmed.ucdavis.edu/research/Funding/STAR/FacultyPages/Paul-Murphy.cfm
Publication(s)
Paul-Murphy J, Ludders JW, Robertson SA, Gaynor JS, Hellyer PW, Wong PL. The need for a cross-species approach to the study of pain in animals. Journal of the American Veterinary Medical Association 224(5): 692-697, 2004.
Importance to Avian Medicine – The treatment of pain is an important component of patient care. However, little is known about avian analgesia and the effects of different drugs and drug classes in different avian species. This project was conducted to investigate the analgesic effects of two opioids, butorphanol and bruprenorphine, in psittacine birds (parrots and parrot-like birds).
1996
Project Title - Pharmacokinetics of buprenorphine in psittacine birds
Investigator - Joanne Paul-Murphy
Institution - University of Wisconsin (current address: University of California at Davis)
Link - http://www.vetmed.ucdavis.edu/research/Funding/STAR/FacultyPages/Paul-Murphy.cfm
Publication(s)
Paul-Murphy J, Hess JC, Fialkowski JP. Pharmacokinetic properties of a single intramuscular dose of buprenorphine in African grey parrots (Psittacus erithacus erithacus). Journal of Avian Medicine and Surgery 18(4): 224-228, 2004.
Abstract - Buprenorphine is a synthetic mixed agonist-antagonist opiate analgesic that is used in a variety of species. To determine if a dose of buprenorphine at 0.1 mg/kg achieves plasma concentrations in parrots that would be analgesic in humans (0.5-1.0 ng/ml), we administered a single dose of buprenorphine (at 0.1 mg/kg) either intramuscularly (5 birds) or intravenously (1 bird) to African grey parrots (Psittacus erithacus erithacus). Serial plasma samples were taken before and at 0.25, 0.5, 0.75, 1.0, 1.5, 2, 6, and 8 hours after administration. For a single intramuscular dose, buprenorphine was rapidly absorbed, and plasma concentrations had a mean residence time of 1.0 hour, elimination half-life of 1.0 hour, and maximum concentration of 68.7 ng/ml, determined by using noncompartmental analysis. This dose of buprenorphine can achieve plasma levels for at least 2 hours in the African grey parrot for comparable analgesic levels in humans, however buprenorphine is not recommended as an analgesic treatment for parrots until pharmacokinetic and analgesia studies are done at higher doses.
Importance to Avian Medicine – The treatment of pain is an important component of patient care. However, little is known about avian analgesia and the effects of opioid analgesics in different avian species. This study was conducted to evaluate the pharmacokinetics of buprenorphine, a mixed agonist-antagonist opioid analgesic, in African grey parrots. The study found that dosing at 0.10 mg/kg maintained plasma levels for at least two hours, but the authors warned that further studies were needed, such as investigating analgesic efficacy, before use of this drug as an analgesic could be recommended.
1997
Project Title - Serum pharmacokinetics of azithromycin, a new antibiotic effective against chlamydial organisms in macaws
Investigator - Marie Josee Limoges
Institution - University of Saskatchewan
Importance to Avian Medicine – Azithromycin is a bacteriostatic macrolide antibiotic with very long tissue half-life in dogs and cats. Chlamydophila psittaci, a chlamydial organism, is the causative agent of psittacosis, an important disease of birds with zoonotic potential. Azithromycin may have efficacy against C. psittaci. This study aimed to investigate the pharmacokinetics of azithromycin in macaws so that dosing recommendations for this drug could be developed.
1997
Project Title - Investigations into the etiologic agent of internal papillomatosis of parrots
Investigator - David Phalen
Institution - Texas A & M University (currently at the University of Sydney)
Link - http://sydney.edu.au/vetscience/about/staff/dphalen.shtml
Publication(s)
Styles DK, Tomaszewski EK, Jaeger LA, Phalen DN. Psittacid herpesviruses associated with mucosal papillomas in neotropical parrots. Virology 325(1): 24-35, 2004.
Abstract - Mucosal papillomas are relatively common lesions in several species of captive neotropical parrots. They cause considerable morbidity and in some cases, result in mortality. Previous efforts to identify papillomavirus DNA and proteins in these lesions have been largely unsuccessful. In contrast, increasing evidence suggests that mucosal papillomas may contain psittacid herpesviruses (PsHVs). In this study, 41 papillomas from 30 neotropical parrots were examined by PCR with PsHV-specific primers. All 41 papillomas were found to contain PsHV DNA. This 100% prevalence of PsHV infection in the papilloma population was found to be significantly higher than PsHV infection prevalence observed in other surveys of captive parrots. PsHV genotypes 1, 2, and 3, but not 4 were found in these lesions. Psittacus erithacus papillomavirus DNA and finch papillomavirus DNA were not found in the papillomas. A papilloma from a hyacinth macaw (Anodorhynchus hyacinthinus) was found to contain cells that had immunoreactivity to antiserum made to the common antigenic region of human papillomavirus (HPV) L1 major capsid protein. However, four other mucosal papillomas were negative for this immunoreactivity, and negative control tissues from a parrot embryo showed a similar staining pattern to that seen in the cloaca papilloma of the hyacinth macaw, strongly suggesting that the staining seen in hyacinth macaw papilloma was nonspecific. Based on these findings, it was concluded that specific genotypes of PsHV play a direct role in the development of mucosal papillomas of neotropical parrots and there is no evidence to suggest the concurrent presence of a papillomavirus in these lesions.
Importance to Avian Medicine - Mucosal papillomas are relatively common in certain captive neotropical parrots. They can cause significant illness, and even death. In this study, 41 papillomas were examined using PCR and all were found to contain psittacid herpesvirus DNA. The study further found that specific types of the virus played different roles in the development of papillomas. The study did not find any evidence of infection with a papillomavirus.
Styles DK, Tomaszewski EK, Phalen DN. A novel psittacid herpesvirus found in African grey parrots (Psittacus erithacus erithacus). Avian Pathology 34(2): 150-154, 2005.
Abstract - DNA from a novel alphaherpesvirus was amplified from a cloacal papilloma, a cutaneous papilloma, and the normal cloacal mucosa of African grey parrots (Psittacus erithacus erithacus). Phylogenetically, the virus was most closely related to the psittacid herpesvirus, but demonstrated sufficient nucleotide and amino acid diversity to be considered a new alphaherpesvirus. It is proposed that the previously described psittacid herpesvirus be designated as psittacid herpesvirus 1 (PsHV-1), and this new species be classified as psittacid herpesvirus 2 (PsHV-2). It is speculated that PsHV-2 co-evolved with the African grey parrot and should therefore be present in these birds in the wild.
Importance to Avian Medicine - Papillomas are relatively common in certain species of parrot. They can cause significant illness, and even death. In this report, a new kind of alphaherpesvirus was identified from a cloacal papilloma, a cutaneous papilloma, and the normal cloacal mucosa from African grey parrots. It was proposed that this new virus be classified as psittacid herpesvirus 2 (PsHV-2).
1998
Project Title - Cisplatin chemotherapy in sulfur crested cockatoos
Investigator - Lucio J. Filippich
Institution - Murdoch University (currently at the University of Queensland, Australia)
Link - http://www.uq.edu.au/vetschool/filippich-assoc-prof-lucio
Publication(s)
Filippich LJ, Bucher AM, Charles BG. Platinum pharmacokinetics in sulphur-crested cockatoos (Cacatua galerita) following single-dose cisplatin infusion. Australian Veterinary Journal 78(6): 406-411, 2000.
Abstract - To determine the pharmacokinetics of platinum (Pt) in cockatoos, a pharmacokinetic study of Pt, following a single IV infusion of cisplatin, was carried out in 6 healthy sulphur-crested cockatoos. Birds were hydrated for 1 h before and 2 h after a 1-h cisplatin infusion (1 mg/kg, IV). Serial blood samples were collected for 96 h after initiation of the infusion and urine was collected for 2 h during the hydration period after cisplatin administration. Tissue samples from 10 organs were obtained at necropsy, 96 h after cisplatin infusion. Total Pt and filterable Pt in plasma, urinary Pt and tissue Pt concentrations were assayed by inductively coupled plasma-mass spectrometry. A noncompartmental pharmacokinetic analysis was performed on the plasma and urine data. For total Pt and filterable Pt, the respective mean systemic clearances were 0.373 and 0.699 L/kg hourly, the steady state volumes of distribution were 4.19 and 0.356 L/kg, and the mean residence times were 111 and 0.512 h. Total plasma Pt displayed a bi-exponential decay profile with average half-lives of 0.398 and 79.0 h, while filterable Pt had a monoexponential decay with mean half-life of 0.413 h. The renal clearance during the 2-h postinfusion period was 0.167 L/kg hourly. The kidneys had the highest Pt accumulation (4.54 µg/g DM). Cisplatin infusion in cockatoos was well tolerated and Pt plasma concentrations were similar to those measured during treatment of solid tumours in human patients. Despite anatomical, physiological and biochemical differences among animal species, the pharmacokinetic disposition of Pt in the cockatoo shares some features with the kinetics reported previously in rodents, dogs and human beings.
Importance to Avian Medicine – Cisplatin is a platinum-containing chemotherapy agent with widespread use in veterinary medicine against tumors such as carcinomas and sarcomas. Cancer also occurs in birds, but little research information exists regarding the use of chemotherapy in birds. This study investigated the drug effects (pharmacokinetics) of cisplatin in cockatoos. The drug was well tolerated in the birds, and at 1 mg/kg IV, plasma levels were similar to those measured during treatment in people.
Filippich LJ, Bucher AM, Charles BG, Sutton RH. Intravenous cisplatin administration in sulphur-crested cockatoos (Cacatua galerita): clinical and pathologic observations. Journal of Avian Medicine and Surgery 15(1): 23-30, 2001.
Abstract - The prevalence of neoplasia in birds is generally low; however, in some species of companion and aviary birds, the incidence is high and neoplasia is a common cause of death. Surgical excision or limb amputation has been performed as the therapeutic plan. Chemotherapy in the treatment of avian neoplasia is largely empirical and poorly documented. For example, cisplatin has been used intralesionally in macaws (Ara species) with limited clinical success. Eight sulphur-crested cockatoos (Cacatua galerita), under general isoflurane anesthesia, were infused intravenously with cisplatin at 6.4 or 1.0 mg/kg over 1 hour and hydrated with lactated Ringer's solution for 1 hour before and 2 hours after cisplatin infusion. Birds were euthanatized 96 hours after infusion, except for 2 birds given the low cisplatin dose, which were euthanatized on day 35 after dosing. All birds tolerated the study procedure while under anesthesia. Blood pressure, heart rate, and respiratory rate did not change significantly. In the low-dose group, the mean cloacal temperature decreased significantly during the infusion period (P < .001) and then rose progressively to preinfusion values by 24 hours. Also in this group, the mean body weight tended to increase during the infusion period before significantly decreasing (P < .05) by 5% at 96 hours after dosing. At 24 hours after dosing, all birds were bright and eating. However, intermittent regurgitation and fecal changes (moist, dark green feces and yellow urates) occurred in 3 of 8 birds, especially those given the high dose. By 72 hours after dosing, droppings in the low-dose group were normal in appearance. One bird in the high-dose group died by 94 hours after dosing. Myelosuppression was not observed in any bird and at necropsy, no evidence of cisplatin toxicity was found except in 1 bird given the high cisplatin dose. On histology, this bird showed nephrotoxicity, and its serum uric acid levels and mean estimated white blood cell count increased significantly by 24 hours after dosing. This paper reports for the first time the effect of systemic cisplatin administration in birds and provides veterinarians data for formulating efficacious and safe protocols for platinum-containing compounds when treating neoplasia in parrots and other companion birds.
Importance to Avian Medicine – Cisplatin is a platinum-containing chemotherapy agent with widespread use in veterinary medicine against tumors such as carcinomas and sarcomas. Cancer also occurs in birds, but little research information exists regarding the use of chemotherapy in birds. This study investigated the clinical effects and safety of cisplatin in cockatoos when administered at 6.4 or 1.0 mg/kg IV. Regurgitation and changes in the droppings occurred in 3 of 8 birds, especially those given the high dose. Only one bird that received the high dose developed signs of toxicity and died.
1998
Project Title - Intraoperative and postoperative analgesic effects of butorphanol in pigeons
Investigator - Joanne Paul-Murphy
Institution - University of Wisconsin (current address: University of California at Davis)
Link - http://www.vetmed.ucdavis.edu/research/Funding/STAR/FacultyPages/Paul-Murphy.cfm
Importance to Avian Medicine - The treatment of pain is an important component of patient care, particularly for the surgical patient. However, little is known about avian analgesia (pain control) and the effects of opioid analgesics in different avian species. This study aimed to evaluate the analgesic effects of butorphanol, a mixed agonist-antagonist opioid, in pigeons during and after surgery.
1999
Project Title - The effect of endoscopic salpingohysterectomy in immature cockatiels on (Nymphicus hollandicus) ovulation
Investigator - Geoffrey W. Pye
Institution - University of Florida (currently at the San Diego Zoo)
Link - http://www.sandiegozoo.org/zoo/index.php
Publication(s)
Pye GW, Bennett RA, Plunske R, Davidson J. Endoscopic salpingohysterectomy of juvenile cockatiels (Nymphicus hollandicus). Journal of Avian Medicine and Surgery 15(2): 90-94, 2001.
Abstract - Endoscopic salpingohysterectomy, a method for controlling reproductive problems like, overproduction of eggs and egg binding, was evaluated in 14 juvenile female cockatiels (Nymphicus hollandicus). During surgery, haemorrhage was negligible, and all 14 procedures were successful. The positive outcomes suggest that the procedure is safe and simple when performed by veterinarians familiar with avian coelomic endoscopic techniques. Endoscopic salpingohysterectomy in juvenile cockatiels could be used to prevent future reproductive problems. Further study is required to evaluate long-term effects and the preventative value of this procedure in cockatiels.
Importance to Avian Medicine – Reproductive disease, including egg binding and uterine prolapse, are very common in pet cockatiels. This study investigated the use of endoscopy (a less invasive surgical approach) to remove the oviduct (uterus) in juvenile cockatiels. All 14 surgeries were considered successful and the authors stated that, with training, this can be a safe and simple procedure.
1999
Project Title - Genetic variation in the psittacine circovirus capsid protein
Investigator - Shane R. Raidal
Institution - Murdoch University, Australia
Link - http://www.cffr.murdoch.edu.au/academic.html
Publication(s)
Bassami MR, Ypelaar I, Berryman D, Wilcox GE, Raidal SR. Genetic diversity of beak and feather disease virus detected in psittacine species in Australia. Virology 279(2): 392-400, 2001.
Abstract - The complete nucleotide sequence of 8 isolates of beak and feather disease virus (BFDV) obtained from a range of infected psittacine species in Australia were compared with those of two BFDV isolates previously reported from Australia and America.
Importance to Avian Medicine – Beak and Feather Disease, a circovirus, is a serious cause of morbidity and mortality in birds and is endemic in the wild cockatoos in Australia. This study investigated the genetic diversity by sequencing the virus from eight isolates from infected birds in Australia
Phenix KV, Weston JH, Ypelaar I, Lavazza A, Smyth JA, Todd D, Wilcox GE, Raidal SR. Nucleotide sequence analysis of a novel circovirus of canaries and its relationship to other members of the genus Circovirus of the family Circoviridae. Journal of General Virology 82(11): 2805-2809, 2001.
Abstract - The circular, single-stranded DNA genome of a novel circovirus of canaries, tentatively named canary circovirus (CaCV), was cloned and sequenced. Sequence analysis indicated that the genome was 1952 nucleotides (nt) in size and had the potential to encode three viral proteins, including the putative capsid and replication-associated (Rep) proteins. The CaCV genome shared greatest sequence similarity (58.3% nt identity) with the newly characterized columbid circovirus (CoCV) and was more distantly related to the two porcine circovirus strains, PCV1 and PCV2, beak and feather disease virus (BFDV) and a recently isolated goose circovirus (GCV) isolate (46.8-50.9% nt identity). In common with other members of the Circovirus genus, several nt structures and amino acid motifs thought to be implicated in virus replication were identified on the putative viral strand. Phylogenetic analysis of both the capsid and Rep protein-coding regions provided further evidence that CaCV is more closely related to CoCV and BFDV and more distantly related to GCV, PCV1 and PCV2.
Importance to Avian Medicine – Circoviruses are an important cause of illness and death in a variety of avian species. A new circovirus was identified in canaries. The genome of this virus was cloned and sequenced, and it was determined that the virus was most similar to columbid circovirus (a circovirus affecting pigeons and doves).
1999
Project Title - Use of skin allografts to repair difficult skin wounds on raptors
Investigator - Steven F. Swaim
Institution - Auburn University
Publication(s)
Stroud PK, Amalsadvala T, Swaim SF. The use of skin flaps and grafts for wound management in raptors. Journal of Avian Medicine and Surgery 17(2): 78-85, 2003.
Abstract and Importance to Avian Medicine - Managing large open wounds in birds is challenging because of the limited amount of skin and the difficulties associated with bandaging. New techniques involving the use of skin flaps, autografts, and extracellular matrix grafts are emerging to the forefront of wound management as viable options in avian patients. Understanding the anatomy of the avian integument is important when considering the use of one of these forms of reconstruction as a wound management technique in birds. Here we review the use of skin grafts and flaps in avian patients in relation to the anatomy of the avian integumentary.
2000
Project Title - Intradermal skin testing in Amazon parrots - Establishing a protocol
Investigator - Carol S. Foil
Institution - Louisiana State University
Publication(s)
Colombini S, Foil CS, Hosgood G, Tully TN. Intradermal skin testing in Hispaniolan parrots (Amazona ventralis). Veterinary Dermatology 11 (4): 271-276, 2000.
Abstract - The purpose of this study was to develop and standardize a protocol for intradermal skin testing in birds. 40 clinically normal Hispaniolan Amazon parrots were anaesthetized and tested by intradermal injection with 0.02 ml of phosphate-buffered saline, histamine phosphate, compound 48/80, codeine phosphate, deionized water, antiavian IgG and rabbit serum. Injection sites were evaluated at 5, 10 and 15 min, 4-6, 24 and 48 h following injection using callipers to measure the diameter of the wheals. A second intradermal skin test was repeated in 20 birds with 0.03 ml of saline, compound 48/80 and codeine phosphate. This study provides the basis for an appropriate protocol for intradermal skin testing in parrots, including recommended site (proventer region), volume of injection (0.02 ml), negative control (saline), positive control (codeine phosphate 1:100 000 w/v) and optimum reading time (5 min). Further study to establish appropriate dosages for test antigens are required.
Importance to Avian Medicine - Feather destructive behavior and dermatitis are common in parrots, and one speculated cause is allergic skin disease. However, little is known about allergic diseases of companion birds. This study developed a protocol for performing intradermal skin testing in Amazon parrots, including suggested injection sites, volume of injection, and optimum reading time.
Nett CS, Hosgood G, Heatley JJ, Foil CS, Tully TN. Evaluation of intravenous fluorescein in intradermal allergy testing in psittacines. Veterinary Dermatology 14 (6): 323-332, 2003.
Abstract - This study was designed to improve the clinical feasibility of intradermal skin testing of psittacine birds using intravenous fluorescein stain. Twenty-five healthy, anaesthetized Hispaniolan Amazon parrots (Amazona ventralis) were injected intravenously with 10 mg kg-1 fluorescein-sodium 1% followed by intradermal injections of 0.02 mL phosphate-buffered saline, histamine phosphate (1:100,000 w/v) and codeine phosphate (1:100,000 w/v) at the sternal apteria. Wheal diameters of reaction sites were measured grossly and under illumination with a Wood's lamp after 5 and 10 min. Fluorescence-enhanced injection sites were scored between 0 and 2, with 0 equivalent to normal skin and 2 equivalent to a plucked feather follicle. The presence of a fluorescent halo around intradermal injections was also recorded. Under Wood's light illumination at 10 min, histamine and saline were evaluated as positive and negative controls, respectively, based on a positive test having a halo and a score of 2. Sensitivity and specificity were each 76% for halo, 84 and 42% for score and 64 and 77% for combination of score and halo, respectively. Further, mean histamine reactions were significantly larger than codeine phosphate and saline (8.8 +/- 0.4 mm; 7.2 +/- 0.3 mm; 5.9 +/- 0.6 mm); however, this finding was not consistent in individual birds. Wheal size, halo presence and score were affected by site location independent from the injected compound. Intravenous fluorescein improved the readability of avian skin tests; however, the compounds tested raised inconsistent reactions in wheal size, score or halo presence. The compound-independent site effect raises concern on the validity of avian skin testing and warrants investigation of other techniques such as in vitro allergy testing. Based on our findings, intradermal allergy testing in psittacines with or without fluorescein is unreliable and cannot be recommended for practical clinical use.
Importance to Avian Medicine – Feather destructive behavior and dermatitis are common in parrots, and one speculated cause is allergic skin disease. However, little is known about allergic diseases of companion birds. This study investigated the use of an intravenous fluorescein stain during intradermal skin testing in Hispaniolan Amazon parrots. Although the dye improved the readability of skin tests, the compounds tested gave inconsistent results. Additional research was recommended.
2000
Project Title - Quantitative ultrasound analysis and magnetic resonance image analysis of iron accumulation in the liver of birds
Investigator - Joanne Paul-Murphy
Institution - University of Wisconsin (current address: University of California at Davis)
Link - http://www.vetmed.ucdavis.edu/research/Funding/STAR/FacultyPages/Paul-Murphy.cfm
Publication(s)
Matheson JS, Paul-Murphy J, O'Brien RT, Steinberg H. Quantitative ultrasound, magnetic resonance imaging, and histologic image analysis of hepatic iron accumulation in pigeons (Columbia livia). Journal of Zoo and Wildlife Medicine 38(2): 222-230, 2007.
Abstract - Iron overload was induced by iron dextran i.v. in clinically healthy adult pigeons, Columbia livia, (n=8). Hemosiderosis was induced in all treated birds. Two control pigeons received no iron injections. Pigeons did not show clinical signs of iron overload during the 6-wk study. Ultrasound examination of the liver in the pigeons receiving iron dextran was performed on days 0, 13, 28, and 42. No ultrasound images were collected on the control pigeons. Magnetic resonance imaging was performed on days 0, 13, 28, and 42 on all study pigeons and imaging sequences were collected in three different imaging formats: T1, T2, and gradient-recalled echo (GRE). Surgical liver biopsies were performed on pigeons receiving iron dextran on days 2, 16, and 45 (at necropsy). A single liver sample was collected at necropsy from the control birds. Histologic examination, quantitative image analysis, and tissue iron analysis by thin-layer chromatography were performed on each liver sample and compared to the imaging studies. Although hemosiderosis was confirmed histologically in each experimental pigeon, no significant change in pixel intensity of the ultrasound images was seen at any point in the study. Signal intensity, in all magnetic resonance imaging formats, significantly decreased in a linear fashion as the accumulation of iron increased.
Importance to Avian Medicine – Iron storage disease is an important disease affecting certain species of birds such as pigeons, doves, and toucans. The diagnosis of this disease can be challenging and historically requires a liver biopsy, which carries some risk to the patient. This study investigated the use of magnetic resonance imaging (or MRI) of the liver compared with liver ultrasound, histology and measurement of iron concentration in pigeons that were induced to develop hemosiderosis (or excess liver iron accumulation). No changes in the appearance of the liver were seen on ultrasound, although significant changes were seen by MRI.
2000
Project Title - Detection and differentiation of psittacid herpesviruses from unapparently infected parrots
Investigator - David Phalen
Institution - Texas A & M University (currently at the University of Sydney)
Link - http://sydney.edu.au/vetscience/about/staff/dphalen.shtml
Publication(s)
Tomaszewski E, Wilson VG, Wigle WL, Phalen DN. Detection and heterogeneity of herpesviruses causing Pacheco's disease in parrots. Journal of Clinical Microbiology 39(2): 533-538, 2001.
Abstract - Pacheco's disease (PD) is a common, often fatal, disease of parrots. We cloned a virus isolate from a parrot that had characteristic lesions of PD. Three viral clones were partially sequenced, demonstrating that this virus was an alphaherpesvirus most closely related to the gallid herpesvirus 1. Five primer sets were developed from these sequences. The primer sets were used with PCR to screen tissues or tissue culture media suspected to contain viruses from 54 outbreaks of PD. The primer sets amplified DNA from all but one sample. Ten amplification patterns were detected, indicating that PD is caused by a genetically heterogeneous population of viruses. A single genetic variant (psittacid herpesvirus variant 1) amplified with all primer sets and was the most common virus variant (62.7%). A single primer set (23F) amplified DNA from all of the positive samples, suggesting that PCR could be used as a rapid postmortem assay for these viruses. PCR was found to be significantly more sensitive than tissue culture for the detection of psittacid herpesviruses.
Importance to Avian Medicine – Pacheco's disease is a common, often fatal, viral disease of parrots. An alphaherpesvirus from a parrot that had Pacheco’s disease was cloned and characterized. Results from this study suggested that PCR for psittacid herpesvirus 1 (PsHV-1) could be used to rapidly screen birds for this disease.
Tomaszewski EK, Kaleta EF, Phalen DN. Molecular phylogeny of the psittacid herpesviruses causing Pacheco's disease: Correlation of genotype with phenotypic expression. Journal of Virology 77(20): 11260-11267, 2003.
Abstract - Fragments of 419 bp of the UL16 open reading frame from 73 psittacid herpesviruses (PsHVs) from the United States and Europe were sequenced. All viruses caused Pacheco's disease, and serotypes of the European isolates were known. A phylogenetic tree derived from these sequences demonstrated that the PsHVs that cause Pacheco's disease comprised four major genotypes, with each genotype including between two and four variants. With the exception of two viruses, the serotypes of the virus isolates could be predicted by the genotypes. Genotypes 1 and 4 corresponded to serotype 1 isolates, genotype 2 corresponded to serotype 2 isolates, and genotype 3 corresponded to serotype 3 isolates. The single serotype 4 virus mapped to genotype 4. DNA from a virus with a unique serotype could not be amplified with primers that amplified DNA from all other PsHVs, and its classification remains unknown. Viruses representing all four genotypes were found in both the United States and Europe, and it was therefore predicted that serotypes 1, 2 and 3 were present in the United States. Serotype 4 was represented by a single European isolate that could not be genetically distinguished from serotype 1 viruses; therefore, the presence of serotype 4 in the United States could not be predicted. Viruses of genotype 4 were found to be the most commonly associated with Pacheco's disease in macaws and conures and were least likely to be isolated in chicken embryo fibroblasts in the United States. All four genotypes caused deaths in Amazon parrots, but genotype 4 was associated with Pacheco's disease only in Amazons in Europe. Genotypes 2, 3 and 4, but not 1, were found in African grey parrots. Although parrots from the Pacific distribution represent a relatively small percentage of the total number of birds with Pacheco's disease, all four genotypes were found to cause disease in these species.
Importance to Avian Medicine – Pacheco's disease is a common, often fatal, viral disease of parrots and is caused by an alphaherpesvirus. This study sequenced the genome of 73 viral isolates from parrots in the United States and Europe. Geographic distribution and species predilection of the four major viral genotypes was characterized.
Tomaszewski EK, Gravendyck M, Kaleta EF, Phalen DN. Genetic characterization of a herpesvirus isolate from a superb starling (Lamprotornis superbus) as a psittacid herpesvirus genotype 1. Avian Diseases 48(1): 212-214, 2004.
Abstract - Four genotypes of the psittacid herpesvirus (PsHV) cause Pacheco disease in parrots. Viruses that are serologically cross-reactive to the PsHVs have also been isolated from passerine species. DNA was amplified from a herpesvirus isolated from a superb starling (Lamprotornis superbus) with PsHV-specific primers and polymerase chain reaction. A comparison of the partial sequence of the UL 16 gene from this herpesvirus with sequences from viruses of known PsHV genotypes showed that the herpesvirus from the superb starling was a PsHV genotype 1 virus. This finding expands the range of birds that are known to be susceptible to PsHV genotype 1 infections and suggests that PsHVs should be considered as a differential in passerines with herpesvirus infections.
Importance to Avian Medicine – Pacheco's disease is a common, often fatal, viral disease of parrots and is caused by an alphaherpesvirus. A herpesvirus isolated from a superb starling was characterized, and the virus was determined to be psittacine herpesvirus 1 (PsHV-1) virus. These results expanded the range of avian species known to be susceptible to infection with PsHV-1.
2001
Project Title - Use of synthetic TSH for evaluation of thyroid function in birds
Investigator - Cheryl Greenacre
Institution - The University of Tennessee
Link - http://www.vet.utk.edu/faculty/greenacre.php
Importance to Avian Medicine – Little is known about diseases of the thyroid gland in companion birds, and yet hypothyroidism is frequently mentioned as a potential cause of abnormal feather growth and molting, as well as feather destructive behavior in parrots. This project aimed to evaluate the use of synthetic thyroid stimulating hormone (TSH) for use in the evaluation of thyroid function in birds.
2001
Project Title - Characterization of avian paramyxoviruses from parrots associated with persistent infection
Investigator - Christian Grund
Institution - Clinic for Poultry, University of Veterinary Medicine Hannover, Germany
2001
Project Title - A fluoroscopic study comparing the difference in time for contrast medium to reach the kidneys when injected into the basilic vein versus the medial metatarsal vein
Investigator - Dennilyn Parker
Institution - University of Saskatchewan
Link - http://www.usask.ca/wcvm/wcvm_people/profiles/Parker_Dennilyn.php
2002
Project Title - Pharmacokinetics of doxorubicin in sulfur-crested cockatoos
Investigator - Lucio J. Filippich
Institution - Murdoch University (currently at the University of Queensland, Australia)
Link - http://www.uq.edu.au/vetschool/filippich-assoc-prof-lucio
Publication(s)
Filippich LJ. Tumor control in birds. Seminars in Avian and Exotic Pet Medicine 13(1): 25-43, 2004.
Abstract and Importance to Avian Medicine - Neoplasia is common in pet birds, especially psittacines, and mainly involves the integument and urogenital system. Before treatment options are considered, a definitive diagnosis should be made and the extent of the disease determined. Treatment should initially be directed at tumour eradication and may involve using several modalities together or sequentially. Surgery, radiotherapy, and photodynamic therapy are used against localized tumors, while chemotherapy and biological response modification are also used against metastatic disease. In combination or adjunct therapy, surgery is used to excise or debulk the tumour, radiotherapy to sterilize local regional disease and chemotherapy and biological therapy to help prevent metastatic disease. The tumour control programme should be rationally planned before application, rather than added on when one modality fails, as is commonly practiced. Tumour response to therapy should be regularly assessed both in the short and long term and wherever possible, assessment should be quantitated. Work place health and safety procedures for radiation and cytotoxic drugs should always be practiced.
Filippich LJ. Microscale HPLC determination of doxorubicin and doxorubicinol in canine and avian plasma samples. Clinical and Experimental Pharmacology and Physiology 31(Suppl 1): A57, 2004 (poster)
Abstract - Samples from pharmacokinetic studies in birds and dogs require a selective, accurate, sensitive and precise method of analysis. We report a new microscale method for the measurement of doxorubicin and its major active metabolite, doxorubicinol, using a protein precipitation-liquid extraction workup and reverse-phase HPLC with fluorescence detection. Doxorubicinol was synthesized from doxorubicin by borohydride reduction. To plasma (100 uL) was added daunorubicin (80 ng) and water (20 uL), then acetonitrile (200 uL) followed by vortex-mixing (30 s) and centrifugation (5 min, ~9300 g). The supernatant fluid was transferred to another tube and vortex-mixed (30 s) with ethyl acetate (2 mL), followed by centrifugation (~900 g, 15 min). The upper (ethyl acetate) phase was pipetted into a fresh tube and vortexed-mixed (30 s) with 0.05 M HCL (100 uL). Following centrifugation (~900 g, 15 min), the upper phase was aspirated gently and discarded. The aqueous phase (70 uL) was injected into the HPLC. Separations were achieved on a LunaTM phenyl hexyl column (5 (m, 100mm 4.6 mm i.d) at 30(C. The mobile phase of acetonitrile (17% v/v) and 0.01 M orthophosphoric acid (83% v/v) was delivered using a programmed flow-rate profile of 1.5 mL/min (0.0–5.5 min), increasing linearly to 2.3 mL/min (5.5–6.5 min), then maintained at 2.3 mL/min (6.5–20 min). The eluent was monitored by a fluorescence detector set to 235 nm (excitation) and 550 nm (emission). Doxorubicinol, doxorubicin and daunorubicin were eluted at 4.3 min, 7.5 min, and 17.0 min, respectively. All peaks were baseline resolved with no interference. The assay imprecision was less than or equal to 17.8% (25 ng/mL) and less than or equal to 5.7% (250 ng/mL). Inaccuracy was less than or equal to 7.9% (25 ng/mL) and less than or equal to 2.5% (250 ng/mL). Calibration plots were linear (r2 > 0.998) and recovery was 62%-87% from 20 ng/mL to 400 ng/mL.
Importance to Avian Medicine – Doxorubicin is a anthracycline glycoside antibiotic chemotherapeutic agent widely used in veterinary medicine. However, dosing strategies, efficacy, and safety studies are lacking in birds. This study was done to develop an accurate and reliable method for measuring plasma concentrations of doxorubicin and doxorubicinol in dogs and birds (microscale HPLC), an important first step before performing research studies investigating pharmacokinetics of the drug in birds.
Gilbert CM, Filippich LJ, Charles BG. Doxorubicin pharmacokinetics following a single-dose infusion to sulphur-crested cockatoos (Cacatua galerita). Australian Veterinary Journal 82(12): 769-772, 2004.
Abstract - Objective: To determine the pharmacokinetics of doxorubicin in sulphur-crested cockatoos, so that its use in clinical studies in birds can be considered. Design: A pharmacokinetic study of doxorubicin, following a single intravenous (IV) infusion over 20 min, was performed in four healthy sulphur-crested cockatoos (Cacatua galerita). Procedure: Birds were anaesthetised and both jugular veins were cannulated, one for doxorubicin infusion and the other for blood collection. Doxorubicin hydrochloride (2 mg/kg) in normal saline was infused IV over 20 min at a constant rate. Serial blood samples were collected for 96 h after initiation of the infusion. Plasma doxorubicin concentrations were assayed using an HPLC method involving ethyl acetate extraction, reverse-phase chromatography and fluorescence detection. The limit of quantification was 20 ng/mL. Established non-parametric methods were used for the analysis of plasma doxorubicin data. Results: During the infusion the mean±SD for the Cmax of doxorubicin was 4037±2577 ng/mL. Plasma concentrations declined biexponentially immediately after the infusion was ceased. There was considerable intersubject variability in all pharmacokinetic variables. The terminal (β-phase) half-life was 41.4±18.5 min, the systemic clearance (Cl) was 45.7±18.0 mL/min/kg, the mean residence time (MRT) was 4.8±1.4 min, and the volume of distribution at steady state (VSS) was 238±131 mL/kg. The extrapolated area under the curve (AUC0-∞) was 950±677 ng/mL.h. The reduced metabolite, doxorubicinol, was detected in the plasma of all four parrots but could be quantified in only one bird with the profile suggesting formation rate-limited pharmacokinetics of doxorubicinol. Conclusions and clinical relevance: Doxorubicin infusion in sulphur-crested cockatoos produced mild, transient inappetence. The volume of distribution per kilogram and terminal half-life were considerably smaller, but the clearance per kilogram was similar to or larger than reported in the dog, rat and humans. Traces of doxorubicinol, a metabolite of doxorubicin, were detected in the plasma.
Importance to Avian Medicine - Doxorubicin is a anthracycline glycoside antibiotic chemotherapeutic agent widely used in veterinary medicine. However, dosing strategies, efficacy, and safety studies are lacking in birds. This study investigated the drug behavior (pharmacokinetics) of doxorubicin in cockatoos when administered at 2 mg/kg IV. Mild, transient inappetence was seen. The results from this study are important in the development of dosing recommendations for this chemotherapy drug in birds.
Gilbert CM, McGeary RP, Filippich LJ, Norris RL, Charles BG. Simultaneous liquid chromatographic determination of doxorubicin and its major metabolite doxorubicinol in parrot plasma. Journal of Chromatography B Analytical Technology Biomedical Life Science. 826(1-2):273-6, 2005.
Abstract - A new microscale method is reported for the determination of doxorubicin and its active metabolite, doxorubicinol, in parrot plasma. Sample workup involved acetonitrile protein precipitation, ethyl acetate extraction, followed by back extraction into HCl. Separations were achieved on a phenyl-hexyl column at 30 degrees C using acetonitrile (17%, v/v) in 0.01 M orthophosphoric acid (83%, v/v) delivered via a linear flow program. Fluorometric detection wavelengths were 235 nm (excitation) and 550 nm (emission). Calibration plots were linear (r2>0.999), and recoveries were 71-87% from 20 to 400 ng/mL. Assay imprecision was <or=8.5% and inaccuracy was <or=6.3%. The limit of quantification was 25 ng/mL.
Importance to Avian Medicine – Doxorubicin is a anthracycline glycoside antibiotic chemotherapeutic agent widely used in veterinary medicine. However, dosing strategies, efficacy, and safety studies are lacking in birds. This study was done to develop an accurate and reliable microscale method for measuring plasma concentrations of doxorubicin and its active metabolite doxorubicinol in parrots, an important first step before performing research studies investigating pharmacokinetics of the drug in birds.
Gilbert CM, Filippich LJ, McGeary RP, Charles BG. Toxicokinetics of the active doxorubicin metabolite, doxorubicinol, in sulphur-crested cockatoos (Cacatua galerita). Research in Veterinary Science 83(1): 123-129, 2007.
Abstract - The pharmacokinetics of doxorubicinol, a cytotoxic metabolite of the anticancer drug, doxorubicin, were studied in four healthy sulphur-crested cockatoos (Cacatua galerita) after a 20 min intravenous infusion of 2 mg/kg. Plasma doxorubicinol concentrations were measured by HPLC. The pharmacokinetic parameters were estimated using a non-compartmental method. The mean (±SD) peak concentration was 8341±3132 µg/L at 17.5±5.0 min after the start of the infusion, and doxorubicinol concentrations declined biexponentially to 154.3±34.5 µg/L, 40 min after the end of the infusion. Systemic clearance was 0.940±0.473 L/h/kg, mean residence time was 0.165±0.133 h, and steady-state volume of distribution was 0.123±0.0526 L/kg. The terminal half-life was 0.660±0.611 h. Detectible but unquantifiable concentrations of doxorubicinol were present in the plasma ultrafiltrate of two birds during the infusion, indicating very extensive plasma protein binding. Physiological, haematological and biochemical monitoring over 3 weeks showed that doxorubicinol at a single infused dose of 2 mg/kg caused no toxicities of major concern.
Importance to Avian Medicine – Doxorubicin is a anthracycline glycoside antibiotic chemotherapeutic agent widely used in veterinary medicine. However, safety studies are lacking in companion birds. This study evaluated the pharmacokinetics of doxorubicinol after a single 2 mg/kg IV injection in cockatoos. No signs of toxicity to the drug were observed.
2002
Project Title - Evaluation of endoscopic castration and salpingohysterectomy using laser ablation in pigeons
Investigator - Stephen J.Divers
Institution - University of Georgia
Link - http://www.vet.uga.edu/hospital/services/exotics/stephenHD.php
Publication(s)
Hernandez-Divers SJ. Minimally invasive endoscopic surgery of birds. Journal of Avian Medicine and Surgery 19(2): 107-120, 2005.
Abstract and Importance to Avian Medicine - Endoscopy has proven to be an important diagnostic tool for avian veterinarians to observe and biopsy internal structures. To date, most of the described endoscopic procedures are single-entry techniques. The use of miniature endoscopic equipment has been pioneered in human pediatric laparoscopy, and many of these techniques can be used in avian medicine. The addition of a second and third port using 2.5- or 3.5-mm cannulae has facilitated the use of 2- or 3-mm instruments within the avian coelom. Triangulation of various instruments coupled with radiosurgical hemostasis has made several endoscopic procedures possible, including salpingohysterectomy and orchidectomy. In addition, endoscope-assisted, minimally invasive procedures, including enterotomy, enterectomy, cloacopexy, and pneumotomy, may be initiated internally and completed by standard surgical techniques. The advent of minimally invasive endoscopic surgery offers important benefits, including rapid and accurate diagnosis, reduced need for an extensive coeliotomy, reduced surgical stress, improved pulmonary function, more stable anesthesia, and reduced surgical and hospitalization periods.
Hernandez-Divers SJ, Stahl SJ, Wilson GH, McBride M, Hernandez-Divers SM, Cooper T, Stedman N. Endoscopic orchidectomy and salpingohysterectomy of pigeons (Columba livia): an avian model for minimally invasive endosurgery. Journal of Avian Medicine and Surgery 21(1): 22-37, 2007.
Abstract - To evaluate a minimally invasive endosurgical system in birds, endoscopic orchidectomy and salpingohysterectomy were evaluated in 11 male and 14 female pigeons (Columba livia). Anesthesia was maintained by using isoflurane delivered by a pressure-cycle ventilator and produced good to excellent anesthesia during 96% of procedures. Endosurgery was performed with a 2.7-mm telescope system, 3-mm human pediatric laparoscopy instruments, and a 4.0-MHz radiofrequency device. Mean±SD surgery times for bilateral orchidectomy and salpingohysterectomy procedures were 39±18 minutes and 34±15 minutes, respectively. Procedures were generally straightforward, with any minor complications easily overcome. Surgical complications were generally minor, with mild hemorrhage and focal coagulative damage to the kidney being most common. All pigeons recovered quickly (20±11 minutes), with 95% displaying good to excellent recoveries. No birds exhibited any clinically apparent morbidity or mortality associated with endosurgery. At least 1 male and 1 female bird were subjected to elective euthanasia and necropsy on postoperative days 1, 3, 5, 10, 20, and 90 to determine the success and side effects of surgery. Gross and histologic abnormalities, when observed, were generally mild, with hemorrhage and partial necrosis of the cranial kidney present in 27% of males. Mild damage or hematoma associated with the left kidney was also reported in 28% of females. The surgical objectives were achieved in 23 of 25 pigeons. The 2 surgical failures (regenerated testes in a male and large oviductal remnant in a female) were attributed to endosurgical inexperience and occurred during the first procedures. Salpingohysterectomy does not appear to prevent ovarian development and ovulation in the pigeon, at least not during the first 3 postoperative months. Orchidectomy and salpingohysterectomy appear to be safe procedures when performed using appropriate equipment and techniques. Endosurgery offers a valuable, minimally invasive alternative to the standard coeliotomy techniques commonly used in birds.
Importance to Avian Medicine – Medical and behavioral disorders of the reproductive tract are very common in companion birds. Removal of the testicles in male birds and the oviduct (uterus) in female birds are used to manage medical and behavioral reproductive disorders. Minimally invasive endoscopic surgical techniques have several advantages over standard surgical methods. This study was done to evaluate the use of minimally invasive endoscopic surgery for removing the testicles in male birds and the oviduct of female birds. Results showed the endosurgery, when performed using appropriate equipment and techniques, appears to be a safe method for removing the testicles and oviduct in birds.
2002
Project Title - Pharmacokinetics of clindamycin in pigeons
Investigator - Thomas Lenarduzzi
Institution - Mississippi State University
Importance to Avian Medicine – Clindamycin is a lincosamide antibiotic that is widely used in veterinary medicine to treat bacterial infections. Although clindamycin is used in avian medicine, little is known about drug behavior in birds. This study aimed to evaluate drug behavior (pharmacokinetics) of clindamycin in pigeons. Pharmacokinetic evaluation is an important early step in the development of dosing recommendations for drugs.
2002
Project Title - Optimization of the skeletal-fixator-intramedullary pin-tie-in fixator for the repair of long bone fractures in birds
Investigator - Arnaud Van Wettere,
Institution - University of Minnesota
Publication(s)
Van Wettere AJ, Wallace LJ, Redig RT, Bourgeault CA , Bechtold BE. Mechanical evaluation of various external skeletal fixator-intramedullary pin tie-in configurations using a tubular plastic bone model. Journal of Avian Medicine and Surgery 23 (4): 263-276, 2009.
Abstract - Use of external skeletal fixator–intramedullary pin tie-in (ESF-IM pin tie-in) fixators is an adjustable and effective method of fracture fixation in birds. The objective of this study was to evaluate the elements of the ESF-IM tie-in configuration used in birds. Ten variations of constructs were applied to a plastic bone model with a standard gap. Variants included non-tied and tie-in configurations, use of a 6- or 10-mm acrylic bar or a thermoplastic connecting bar, variation in the placement of the proximal fixation pin, use of 1.1-mm (0.045-in) or 1.6-mm (0.062-in) fixation pins, and configurations of 2, 3, or 4 fixation pins. The various constructs were loaded in bending, torque, and compression, and response variables were determined from resulting load-displacement curves (stiffness, load at 1-mm displacement). Results showed that, by using the tie-in configuration, increasing the diameter of the acrylic connecting bar, and increasing the diameter or number of fixation pins, each significantly increased the stiffness in all assessments. Placing the fixation pin distally in the proximal bone model segment increased the stiffness in bending, and adding a fixation pin to the distal bone model segment increased the stiffness in torque and bending. These results quantified the relative importance of specific parameters that effect stiffness and safe load of the ESF-IM tie-in construct as applied to a plastic bone fracture model.
Importance to Avian Medicine – Use of external skeletal fixator–intramedullary pin tie-in (ESF-IM pin tie-in) fixators is an adjustable and effective method of fracture fixation in birds. This study evaluated the elements of the ESF-IM tie-in configuration in birds. Results of the study that the tie-in configuration increased the stiffness of fixation against torque and bending forces.
Van Wettere AJ, Redig PT, Wallace LJ, Bourgeault CA, Bechtold JE. Mechanical evaluation of external skeletal fixator-intramedullary pin tie-in configurations applied to cadaveral humeri from red-tailed hawks (Buteo jamaicensis). Journal of Avian Medicine and Surgery 23(4):277-285, 2009.
Abstract - Use of external skeletal fixator-intramedullary pin (ESF-IM) tie-in fixators is an adjustable and effective method of fracture fixation in birds. The objective of this study was to determine the contribution of each of the following parameters to the compressive and torsional rigidity of an ESF-IM pin tie-in applied to avian bones with an osteotomy gap: (1) varying the fixation pin position in the proximal bone segment and (2) increasing the number of fixation pins in one or both bone segments. ESF-IM pin tie-in constructs were applied to humeri harvested from red-tailed hawks (Buteo jamaicensis) (n=24) that had been euthanatized for clinical reasons. Constructs with a variation in the placement of the proximal fixation pin and with 2, 3, or 4 fixation pins applied to avian bone with an osteotomy gap were loaded to a defined displacement in torque and axial compression. Response variables were determined from resulting load-displacement curves (construct stiffness, load at 1-mm displacement). Increasing the number of fixation pins from 1 to 2 per bone segment significantly increased the stiffness in torque (110%) and compression (60%), and the safe load in torque (107%) and compression (50%). Adding a fixation pin to the distal bone segment to form a 3-pin fixator significantly increased the stiffness (27%) and safe load (20%) in torque but not in axial compression. In the configuration with 2 fixation pins, placing the proximal pin distally in the proximal bone segment significantly increased the stiffness in torque (28%), and the safe load in torque (23%) and in axial compression (32%). Results quantified the relative importance of specific parameters affecting the rigidity of ESF-IM pin tie-in constructs as applied to unstable bone fracture models in birds.
Importance to Avian Medicine – The external skeletal fixator-intramedullary pin (ESF-IM) tie-in fixator is an adjustable and effective method for fracture repair in birds. This study evaluated different tie-in permutations for stabilization of humeral fractures in red-tailed hawks. The results of this study provide avian surgeons important guidelines for the use of the ESF-IM in order to improve the chances for a successful fracture repair.
2003
Project Title - Internal anatomy of the hornbill casque described by radiography and advanced imaging
Investigator - Kathryn C.Gamble
Instutition - Lincoln Park Zoo
Link - http://www.lpzoo.org/conservation/who_we_are/k_gamble.php
Publication(s)
Gamble KC. Internal anatomy of the hornbill casque described by radiography, contrast radiography, and computed tomography. Journal of Avian Medicine and Surgery 21(1): 38-49, 2007.
Abstract - Hornbills are distinguished from most other avian taxa by the presence of a casque on the dorsal maxillary beak, which, in all but 1 of the 54 extant hornbill species, is described as essentially an air-filled cavity enclosed by minimal cancellous bone. The external casque has been described in detail, but little has been described about its internal anatomy and the communications between the casque and the paranasal sinuses. In this study, 10 intact casque and skull specimens of 7 hornbill species were collected opportunistically at necropsy. The anatomy of the casque and the skull for each of the specimens was examined by radiography, contrast radiography, and computed tomography. After imaging, 8 specimens were submitted for osteologic preparation to directly visualize the casque and the skull interior. Through this standardized review, the baseline anatomy of the internal casque was described, including identification of a novel casque sinus within the paranasal sinus system. These observations will assist clinicians in the diagnosis and treatment of diseases of the casque in hornbill species.
Importance to Avian Medicine – Hornbills are distinguished from most other avian taxa by the presence of a casque on the dorsal maxillary beak. This study utilized plain radiography (X-rays), contrast radiography, and computed tomography (CT) to further characterize the hornbill casque. These results may prove helpful in the clinical evaluation and treatment of diseases involving the hornbill casque.
2004
Project Title - Variability of distribution and stability of extemporaneous preparations of meloxicam and carprofen after dilution and suspension at two 
storage temperatures
Investigator - Michelle Hawkins
Institution - University of California
Link - http://faculty.vetmed.ucdavis.edu/faculty/mghawkins/
Publication(s)
Hawkins MG, Karriker MJ, Wiebe V, Taylor IT, Kass PH. Drug distribution and stability in extemporaneous preparations of meloxicam and carprofen after dilution and suspension at two storage temperatures. Journal of the American Veterinary Medical Association 229(6): 968-974, 2006.
Abstract - Objective - To determine dispersion uniformity and stability of meloxicam and carprofen in extemporaneous preparations stored for 28 days. Design - Prospective study. Sample Population - Meloxicam and carprofen (commercial formulations) were compounded (day 0) with deionized water (DW), 1% methylcellulose gel (MCG), MCG and simple syrup (SS; 1:1 mixture), or a suspending and flavoring vehicle combination (SFVC; 1:1 mixture) to nominal drug concentrations of 0.25, 0.5, or 1.0 mg/mL and 1.25, 2.5, or 5.0 mg/mL, respectively. Procedures - Preparations were stored at approximately 4°C (39.2°F) or 22°C (71.6°F). For each preparation, drug concentrations were determined and drug stability was evaluated at intervals during storage; on days 0 and 28, pH values were measured and bacterial cultures were initiated. Results - In meloxicam-DW, meloxicam-MCG (0.25 mg/mL), and meloxicam-MCG (0.5 mg/mL) preparations, drug distribution was uniform (coefficient of variation <10%); >90% of the original drug concentration was maintained for 28 days. Despite uniform drug distribution of the carprofen-SFVC preparations, most retained ≥90% of the original drug concentration for only 21 days. Use of the MCG-SS combination resulted in foamy preparations of unacceptable variability. After 28 days, pH decreased slightly in meloxicam-DW and meloxicam-MCG preparations (0.17±0.04 and 0.21±0.04, respectively). Carprofen-SFVC (2.5 mg/mL) and carprofen-MCG-SS (5.0 mg/mL) preparations stored at 22°C for 28 days yielded bacterial growth. Conclusions and Clinical Relevance - DW, MCG, and the SFVC can be used successfully for extemporaneous preparation of meloxicam and carprofen for administration to small exotic animals. Refrigeration is recommended for preparations of meloxicam-DW and carprofen-SFVC.
Importance to Avian Medicine – Meloxicam and carprofen are non-steroidal anti-inflammatory (NSAID) agents commonly prescribed in avian medicine for the treatment of pain and inflammation. However, these drugs may not be available in a suitable formulation or concentration and are often extemporaneously compounded. The stabilities of compounded formulations of meloxicam and carprofen in several vehicles were determined in this study
2005
Project Title - Investigation into the antemortem diagnosis and etiology of avian mycobacteriosis
Investigator - Miguel Saggese
Institution - Texas A & M University (currently at Western University of Health Sciences)
Link - http://www.westernu.edu/stp/bios.php?bio=msaggese
Publication(s)
Saggese MD, Riggs G, Tizard I, Bratton G, Taylor R, Phalen DN. Gross and microscopic findings and investigation of the aetiopathogenesis of mycobacteriosis in a captive population of white-winged ducks (Cairina scutulata). Avian Pathology 36(5): 415-422, 2007.
Abstract - The white-winged duck (Cairina scutulata) is critically endangered. Breeding collections of this duck are established in the United Kingdom and the USA. Infection with Mycobacterium avium avium serotype 1 is a major cause of mortality in the UK collection. In this study, the aetiopathogenesis of deaths occurring in the US collection was studied. All ducks (n=21) that died over a 21-month period were examined. Mycobacteriosis was diagnosed in 20 ducks, killing 19 of them. Multifocal to diffuse granulomatous lesions, often with abundant intralesional organisms, were seen in all 20 ducks. Unusual manifestations of this disease were the extensive involvement of the respiratory system and the absence of multinucleated giant cells. Sequence analysis showed that the ducks were infected with a sequevar of M. a. avium that contains serotypes 2, 3, 4, and 9. Given that the long-term ingestion of metals affects immune function, we measured an array of such elements in the liver of six ducks. Concentrations were undetectable or low. The disseminated nature of the disease, high concentration of mycobacteria and absence of multinucleated giant cells within lesions suggest that these ducks were unable to effectively kill the mycobacteria and point to a possible defect or inhibition in cell mediated immunity. Taken together with previously reported UK data, these results suggest that captive white-winged ducks are highly susceptible to at least two sequevars of M. a. avium and that mycobacteriosis is a major threat to ex situ breeding. We hypothesize that the minimal heterozygosis previously shown in these ducks could be contributing to an apparently ineffective immune response.
Importance to Avian Medicine - The white-winged duck is critically endangered and breeding collections have been established in the United Kingdom and the USA. Infection with Mycobacterium avium avium serotype 1 is a major cause of mortality in the UK collection. Results from this study showed that the ducks were unable to effectively kill the mycobacteria, suggesting a possible defect or inhibition in cell mediated immunity, which may have a genetic basis.
Gray PL, Saggese MD, Phalen DN, Tizard I. Humoral response to Mycobacterium avium subsp. avium in naturally infected ring-neck doves (Streptopelia risoria). Veterinary Immunology and Immunopathology 125 (3/4): 216-224, 2008.
Abstract - Creation of a reliable and easy to use serologic test would greatly improve ante mortem diagnosis of Mycobacterium avium subsp. avium and aid in the control of avian mycobacteriosis, particularly in captive birds. In order to determine whether serodiagnostics could be of value in testing ring-neck doves (Streptopelia risoria) for M. a. avium infection, Western blot analysis was used to assess the humoral response of ring-neck doves exposed to M. a. avium, and to evaluate whether an association could be made between the humoral response and necropsy findings, histopathology, culture, and PCR testing. Western blot results were examined for reactivity patterns associating humoral response with infection status, severity and type of lesions (diffuse vs. multifocal granulomatous inflammation) and phenotype (white vs. non-white). A sensitivity of 88.24% and a specificity of 100% were achieved utilizing Western blot analysis to detect M. a. avium infection in ring-neck doves, offering a negative predictive value of 93% and a positive predictive value of 100%. While Western blot analysis results did not reflect lesion severity, lesion type did partially correspond with the humoral response. The findings of the present study indicate that serologic testing can be used as a valuable ante mortem screening tool for identifying ring-neck doves infected with M. a. avium.
Importance to Avian Medicine – Mycobacteriosis is a common and serious disease of captive birds. Creation of a reliable and easy to use serologic test would greatly improve ante mortem diagnosis of avian mycobacteriosis. Results from this study investigating the serologic response to infection in ring-necked doves showed that while serology was not correlated with lesion severity, serology can be a useful antemortem screening tool for mycobacteriosis.
Saggese MD, Tizard I, Phalen DN. Mycobacteriosis in naturally infected ring-neck doves (Streptopelia risoria): investigation of the association between feather colour and susceptibility to infection, disease and lesions type. Avian Pathology 37(4): 443-450, 2008.
Abstract - Prevalence of infection and disease, the degree of organ involvement and the nature of the lesions were investigated in 11 white and 18 non-white ring-neck doves coming from a flock naturally infected with Mycobacterium avium subsp. avium. Lesions were common in the liver, spleen, lung, kidney, intestines, ovary and bone marrow. Overall, 18 out of 29 (62%) birds were considered infected with a sequevar of M. avium subsp. avium that contains serotypes 2, 3, 4 and 9. The prevalence of infection in the white doves (36.4%) was significantly lower than in the non-white morphs (77.7%). White doves had on average fewer organs affected (mean=3.1) than the non-white doves (mean=5.9). A diffuse pattern of inflammation in the liver and spleen was observed mainly in non-white doves. Focal or multifocal granulomatous inflammation of the liver and spleen was predominant in white doves. Genetic mechanisms of immunity to mycobacteriosis may be contributing or determining these differences. There are three basic colour morphs in ring-neck doves - dark or wild type, blond and white - and the alleles coding for colour are sex-linked and located on the sex (Z) chromosome. Female's single sexual chromosomed (ZW) and homozygous males (ZZ) can be white if they carry the white alleles. It is very probable that the gene or genes modulating the immune response to M. avium subsp. avium infection in these doves could be associated to these loci or at least located in the same (Z) chromosome, as the association with white colour suggests.
Importance to Avian Medicine – Mycobacteriosis is a common and serious disease of captive birds. This study investigated the prevalence of infection and disease, the degree of organ involvement and the nature of the lesions in ring-neck doves coming from a flock naturally infected with Mycobacterium avium subsp. avium.
2006
Project Title - Functional imaging of the avian brain during pain and the response to opioid administration
Investigator - Joanne Paul-Murphy
Institution - University of Wisconsin (current address: University of California at Davis)
Link - http://www.vetmed.ucdavis.edu/research/Funding/STAR/FacultyPages/Paul-Murphy.cfm
Importance to Avian Medicine – Control and reduction of pain and discomfort is vitally important in veterinary patient management. However, little is known regarding the response of the avian brain to painful stimuli and the effects of opioid analgesic drugs on these responses. This study aimed to investigate these responses in birds using advanced imaging techniques. Results of this study could prove valuable to avian veterinarians in helping reduce or eliminate patient pain and discomfort.
2007
Project Title - Single-dose pharmacokinetics of piperacillin/tazobactam in the Hispaniolan Amazon parrot (Amazona ventralis)
Investigator - James W. Carpenter
Institution - Kansas State University
Link - http://www.vet.ksu.edu/depts/ClinicalSciences/faculty/carpenter.htm
Importance to Avian Medicine – Piperacillin is a penicillin antibiotic and tazobactam is a beta-lactamase inhibitor. In some studies, piperacillin/tazobactam combinations have been shown to be more effective than other antibiotics against certain bacteria. Although piperacillin/tazobactam combinations are used in avian medicine, little is known about drug behavior (pharmacokinetics) in birds. This study aimed to evaluate drug pharmacokinetics in Hispaniolan Amazon parrots. Pharmacokinetic evaluation is an important early step in the development of dosing recommendations for drugs.
2007
Project Title - The survival of captive reared kakï (black stilt) released to the wild
Investigator - Louisa Robertson
Institution - Massey University, New Zealand
Publication(s)
Master’s Thesis, 2009
Abstract - The continued existence of New Zealand’s critically endangered and endemic black stilt or kakï (Himantopus novaezelandiae) currently relies on an intensive captive management programme. While this is successful at rearing large numbers of birds for release to the wild, poor survivability of these birds is limiting significant increases in the wild population. Predation and starvation are suspected to be the most common causes of death in released birds, but underlying contributing factors to these mortalities have not been fully evaluated. This research investigates the possible contribution of gastrointestinal (GI) helminth burdens and suboptimal digestive organ development to the high mortality rates of released kakï. Emphasis is placed on evaluating the methods used to assess the importance of these factors and to make informed recommendations for future management. The efficacy of the anthelmintic regime used for kakï was assessed by dosing half of the 80 captive birds with praziquantel (PZQ) prior to release. Faecal samples were collected before and after anthelmintic treatment, and before and after release to the wild. Post mortem worm counts were conducted on 11 birds that died following release. The main findings were: PZQ had high efficacy against trematodes; treatment did not prevent re-infection; birds were exposed to helminths at release sites; and there was no advantage of treatment for survival. Overall, the results suggest that anthelmintic treatment is an unnecessary cost. Consequently, recommendations were made to cease anthelmintic treatment or reduce its intensity, continue health screening, and incorporate annual efficacy testing to monitor the emergence of anthelmintic resistance. The reliability of faecal screening for GI helminths was evaluated. Faecal egg counts (FECs) were found to be poor indicators of worm burden. The two modified sedimentation methods used to detect trematodes provided relatively low egg recovery rates. Trematode egg shedding varied between days but not by hour of the day or temperature. The collection and analysis of pooled faecal samples proved to be more cost and time-effective than samples from individual birds and the larger masses collected resulted in greater sensitivity. In conclusion, faecal analysis of pooled samples is a useful qualitative indicator of helminth presence or absence but is quantitatively unreliable. The digestive organs of healthy and emaciated captive, released and wild Himantopus sp. were compared. Captive and released kaki had generally smaller digestive organs than wild birds although released birds did not increase digestive organ size to match the high fibre wild diet and emaciated birds did not have atrophied organs. However, the greatest mortality rates occurred soon after release, while the birds were still being supplementary fed. These results suggest that reduced digestive efficiency is probably not contributing significantly to mortality rates and the direct impacts of the translocation are probably greater risk factors. The continued provision of supplementary food to released birds and an increased focus on habitat enhancement and predator control at release sites were recommended. The reliability of comparing fresh and formalin fixed Himantopus sp. Gut specimens was evaluated. Significant differences in fresh and formalin fixed organ dry masses and variation in preserved organ lengths indicate that this variation should be considered in future studies. In conclusion, current management practices appear to be successful in ensuring that GI helminthes and reduced digestive efficiency do not significantly lower the survivorship of captive-reared and released kakї. There is a need for further research into developing a more direct physiological assessment of the impacts of GI helminths and gut morphology as well as considering the role that starvation may have on poor survivability.
Importance to Avian Medicine - The continued existence of New Zealand’s critically endangered and endemic black stilt (or kakï) currently relies on an intensive captive management program. This study investigated management practices intended to reduce gastrointestinal parasitic infections through the use of anthelminthic drugs, to improve nutritional status by continuing to provided sources of food to newly released birds, and to provide a safe habitat to newly released birds. Results from this study showed that the current management practices were not lowering survivability of captive-reared and released birds.
2008
Project Title - Magnetic resonance imaging of the brain in four avian species
Investigator - Pat Redig
Institution - University of Minnesota
2008
Project Title - Pharmacokinetics of butorphanol after intravenous, intramuscular, and oral administration in Hispaniolan Amazon parrots (Amazona ventralis)
Investigator - David Sanchez-Migallon Guzman
Institution - Louisiana State University (currently at the University of California at Davis)
Link - http://www.vetmed.ucdavis.edu/vmth/small_animal/cape/default.cfm
Sanchez-Migallon Guzman D, Flammer K, Paul-Murphy J, Barker S, Tully TN. Pharmacokinetics of butorphanol after oral, intravenous and intramuscular administration in Hispaniolan Amazon parrots (Amazona ventralis). Submitted to the Journal of Avian Medicine and Surgery. Accepted for publication.
Importance to Avian Medicine - Butorphanol tartrate, an analgesic, is currently considered the drug of choice for pain management in birds. This study provides information regarding absorption through different routes of administration and the elimination of this drug in parrots. The results aid to determine adequate route of administration, frequency and dosage required, and provide critical information for adequate pain management in these birds.
2009
Project Title - Renal, gastrointestinal, and hemostatic effects of meloxicam in Hispaniolan Amazon parrots (Amazona ventralis)
Investigator - Joanne Paul-Murphy
Institution - University of Wisconsin (current address: University of California at Davis)
Link - http://www.vetmed.ucdavis.edu/research/Funding/STAR/FacultyPages/Paul-Murphy.cfm
Importance to Avian Medicine – Meloxicam is a commonly used non-steroidal anti-inflammatory (NSAID) agent in avian medicine for the treatment of pain and inflammation. Although previous studies have shown that meloxicam is an effective analgesic drug in companion bird species, virtually no research has been done on the safety of the drug. This study aims to evaluate the avian kidneys, coagulation system, and gastrointestinal tract (common sites for adverse reactions) for toxicity to the drug.
2010
Project Title - Identifying inflammatory markers associated with trauma and infection in raptors
Investigator - Lisa Tell
Institution - University of California at Davis
Link - http://faculty.vetmed.ucdavis.edu/faculty/latell/
Importance to Avian Medicine - There are limited tools available to veterinarians for assessing raptor health. Due to the small number of diagnostic tests developed for avian patients, an acute phase protein (APP) panel could represent a significant advance in diagnostic methods for indicating health problems that are not otherwise obvious, such as early or subclinical disease or internal injury. APPs could also allow assessment of the severity of infection or injury in raptors presented to avian clinics, providing a prognosis and guiding the course of treatment. While there has been some work evaluating the potential for plasma proteins to serve as biomarkers of condition using plasma protein electrophoresis (EP), EP’s coarse scale of resolution can make it difficult to differentiate between changes in protein levels due to disease, or factors unrelated to disease such as reproductive state. The more detailed information provided by functional assays of individual APPs should allow development of tests that are not as confounded by such non-disease related variation.
