Tumor control in birds

Prevalence, Anatomical Distribution, and Risk Factors of Adipocytic Tumors and Xanthomas in Psittaciformes: 1096 Cases (1998-2018)

Adipocytic tumors are mesenchymal tumors that are commonly reported in psittacine birds; however, large-scale studies evaluating their prevalence and associated risk factors are lacking. A retrospective study of adipocytic tumors in psittacine birds was performed by reviewing pathology submissions from the University of California, Davis-Drury Reavill Pathology Database, containing 26 013 submissions from psittacine birds (1998-2018). Age, sex, genus, anatomic distribution, and pathological diagnosis were collected for each case when available. The prevalence, risk factors, and association with other lipid-accumulation disorders were reported. A total of 450 cases of lipoma, 129 cases of myelolipoma, 35 cases of hemangiolipoma, 31 cases of liposarcoma, and 451 cases of xanthoma were identified. The prevalence of adipocytic tumors and xanthomas on necropsy was 1.3% (158/11 737, 95% confidence interval [CI]: 1.1-1.6). Adipocytic tumors were identified in 27 genera. Amazona (odds ratio [OR] = 1.93, 95% CI: 1.24-2.99, p = 0.004), Myiopsitta (OR = 2.3, 95% CI: 1.0-5.2, p = 0.041), Melopsittacus (OR = 3.4, 95% CI: 2.1-5.5, p < 0.001), and Agapornis (OR = 3.5, 95% CI: 2.0-6.1, p < 0.001) had significantly higher odds of developing adipocytic tumors compared with other genera, whereas Ara had significantly lower odds (OR = 0.5, 95% CI: 0.3-0.9, p = 0.030). Age was also a significant risk factor for many types of adipocytic tumors. There was no significant association between general adipocytic tumor formation and atherosclerosis or hepatic lipidosis. Xanthomas were associated with atherosclerosis (OR = 1.88, 95% CI: 1.01-3.51, p = 0.048), but not hepatic lipidosis (p = 0.503). On necropsy, the trunk and air sacs were the most common sites of xanthoma formation, whereas the trunk and liver were the most common sites of lipoma and myelolipoma formation, respectively.

Myxoid leiomyosarcoma of the oviduct and uterus in a Cockatiel (Nymphicus hollandicus)

An 11-year-old female cinnamon cockatiel (Nymphicus hollandicus) was presented with a coelomic distention. Dystocia was suspected, given its previous history of a calcium-deficient diet and multiple instances of nonobstructive dystocia. Exploratory coeliotomy revealed a large intraluminal mass extending through the magnum to the uterus (shell gland). Metastasis and multiorgan involvement were not seen. Histopathologically, malignant and invasive fascicles of spindle cells were associated with abundant myxoid matrix and hypocellular areas. Multinucleation, bizarre cells and atypical mitotic figures were prominent. Masson's trichrome staining verified the muscular origin, and the myxoid matrix was demonstrated utilizing Alcian blue. The neoplastic cells exhibited alpha-smooth muscle actin and desmin immunoreactivity and were negative for vimentin. Thus, the patient was diagnosed with oviductal and uterine myxoid leiomyosarcoma (LMS). The patient survived 34 days post-surgery before death associated with suspected enteritis. Myxoid LMS is an extremely rare neoplasm in animals. To our knowledge, myxoid LMS has not been reported previously in pet birds.

Palliative Radiation Therapy for Treatment of Cutaneous T-cell Lymphoma in a Double Yellow-headed Amazon Parrot (Amazona oratrix)

A 17-year-old captive female double yellow-headed Amazon parrot (Amazona oratrix) was presented to the Kansas State University Zoological Medicine Service (Manhattan, KS, USA) for a 2-month history of a left sided facial swelling. On examination, a red, raised mass was noted on the left side of the face. A whole-body computed tomography scan of the bird was performed to assess the extent of the mass and evaluate the patient for obvious evidence of disseminated disease. No systemic involvement was detected, and the swelling was localized to the cutaneous and subcutaneous tissues overlying the left rhamphotheca. Two punch biopsies were collected, and histopathology was consistent with cutaneous lymphoma, with strong positive CD3 staining congruous with a T-cell origin. Because of a lack of evidence for disseminated disease, the authors elected to pursue localized radiation therapy, and a single fraction of 8 Gray was administered. The swelling had resolved by the time of the recheck examination 4 weeks post-radiation therapy, and the patient remained clinically normal 52 weeks after radiation therapy.

Fibrolipoma subcutáneo en Loro Amazónico (Amazona aestiva): Evaluación clínica, histopatológica y técnica quirúrgica

Los lipomas son neoplasias benignas conformadas por adipocitos bien diferenciados, delimitados por un delicado estroma fibroso reticular. Éstos constituyen el tumor cutáneo más frecuente en aves, siendo masas blandas que generalmente aparecen en el tejido subcutáneo. Se describe el caso de un loro amazónico (Amazona aestiva) en cautiverio, que fue llevado a consulta debido a una masa ulcerada en la región de la cadera. El diagnóstico citológico refirió que se trataba de un lipoma, y ante la ineficacia del tratamiento local, se procedió con la extirpación quirúrgica de la masa. El tratamiento posquirúrgico consistió en limpiezas con clorhexidina al 0,5 % por 15 días (d), e ibuprofeno por vía oral, por 3 d. La masa fue remitida para su estudio histopatológico, refiriendo como diagnóstico morfológico un fibrolipoma. Los puntos de sutura fueron retirados a los 18 d, observándose una cicatrización completa.

Telangiectatic Osteosarcoma of the Tibiotarsus in a North Island Brown Kiwi (Apteryx mantelli)

A North Island brown kiwi (Apteryx mantelli) with lameness and weight loss had a telangiectatic osteosarcoma. The left proximal tibiotarsus had bony lysis with multiple blood-filled spaces separated by thick fibrous septa and neoplastic mesenchymal cells producing osteoid (5-bromo-4-chloro-3'-indolyl phosphate/nitro blue tetrazolium positive on cytology). No metastases were noted on necropsy.

On the importance of integrating comparative anatomy and One Health perspectives in anatomy education

As a result of many factors, including climate change, unrestricted population growth, widespread deforestation and intensive agriculture, a new pattern of diseases in humans is emerging. With increasing encroachment by human societies into wild domains, the interfaces between human and animal ecosystems are gradually eroding. Such changes have led to zoonoses, vector‐borne diseases, infectious diseases and, most importantly, the emergence of antimicrobial‐resistant microbial strains as challenges for human health. Now would seem to be an opportune time to revisit old concepts of health and redefine some of these in the light of emerging challenges. The One Health concept addresses some of the demands of modern medical education by providing a holistic approach to explaining diseases that result from a complex set of interactions between humans, environment and animals, rather than just an amalgamation of isolated signs and symptoms. An added advantage is that the scope of One Health concepts has now expanded to include genetic diseases due to advancements in omics technology. Inspired by such ideas, a symposium was organised as part of the 19^th International Federation of Associations of Anatomists (IFAA) Congress (August 2019) to investigate the scope of One Health concepts and comparative anatomy in contemporary medical education. Speakers with expertise in both human and veterinary anatomy participated in the symposium and provided examples where these two disciplines, which have so far evolved largely independent of each other, can collaborate for mutual benefit. Finally, the speakers identified some key concepts of One Health that should be prioritised and discussed the diverse opportunities available to integrate these priorities into a broader perspective that would attempt to explain and manage diseases within the scopes of human and veterinary medicine.

Malignant Melanoma in a Long-legged Buzzard (Buteo rufinus): Characterization of Clinical and Histologic Lesions

A 17-year-old, male long-legged buzzard (Buteo rufinus) presented for acute lethargy and black gelatinous tissue in both nostrils. Despite intensive care, the bird died within 2 days. A postmortem computed tomographic scan of the head revealed a complete obstruction of the rostral infraorbital sinus, later confirmed by necropsy. Postmortem examination also highlighted multifocal, black, infiltrating nodules of various sizes (2 mm to 2 cm in diameter) in almost all internal organs: lungs, heart (pericardium, myocardium, endocardium), kidneys, pancreas, adrenals, muscles, and bones (periosteum and medulla). Histologically, the nodules were composed of anaplastic cells containing abundant melanin pigment, consistent with a disseminated melanoma. Malignant melanomas are aggressive neoplasms frequently reported in mammals but rarely found in avian species. In Accipitridae and Falconidae, only 2 cases have been reported.

The Sustainability of Keeping Birds as Pets: Should Any Be Kept?

Simple Summary

The trade in birds for pet trade is harming wild bird populations and bird welfare. Inadequate housing of many pet birds results in stereotypies and other indicators of poor welfare in the birds that are currently widespread. Some pet birds were taken from the wild or bred in poor conditions, while others had nutritional, health, and behavioral problems resulting from inadequate living conditions and incorrect husbandry by the bird owners. As a consequence, it is not ethically right to keep the majority of the birds that are at present kept as pets. If birds are to be continued as a companion animal for people, then more effort should be made by pet shop owners and veterinarians to supply literature to prospective owners highlighting not only the proper care for the species of bird but also its needs and requirements, so that bird owners can do their utmost to meet them. Owners do not comply with laws requiring duty of care, unless they obtain and act on such information and also have knowledge of how to provide good nutrition and minimize the risk of disease. New laws are needed to prohibit taking birds from the wild and keeping birds in conditions that do not meet their needs.

Abstract

We describe a wide range of unethical and unsustainable practices inherent to the trading and keeping of pet birds. At present, biodiversity and wild bird populations are being greatly harmed and many individual birds have poor welfare. Wild-caught birds should not be sold to the public as pets, or to breeding establishments for several reasons, including because 75–90% of wild-caught birds die before the point of sale and taking birds from the wild has negative effects on biodiversity. The housing provided for pet birds should meet the needs of birds of that species and allow good welfare, for example there should be no small cages but aviaries with space for each bird to exercise adequately, and social birds should be kept in social groups. At present, inadequate housing of many pet birds results in stereotypies and other indicators of poor welfare in birds. Owners should have knowledge of how to provide good nutrition and minimize the risk of disease. Unless these changes are made, keeping birds as pets should not be permitted. New laws are needed to prohibit taking birds from the wild and ensure captive pet birds in conditions that do meet their needs.

Characterization of an Unusual Mesenchymal Tumor in the Proventriculus of a Free-ranging Red-tailed Hawk (Buteo jamaicensis)

An adult, female red-tailed hawk (Buteo jamaicensis) was presented for examination after being found unable to fly on a private citizen's property. Further diagnostic testing revealed a vascular, soft tissue mass arising from the serosal surface of the proximal proventriculus. Postmortem histological and immunohistochemical examination of the mass revealed an unusual mesenchymal tumor with features consistent with a leiomyoma or low-grade gastrointestinal stromal tumor.

Multiple Infiltrative Intraosseous Lipomas in the Appendicular Skeleton of a Rose-breasted Cockatoo (Eolophus roseicapilla) with a Humeral Fracture

A 9-year-old female rose-breasted cockatoo (Eolophus roseicapilla) was presented for a humeral fracture. At presentation, the bird was severely lethargic and obese. On physical examination, an open right humeral fracture, healed left ulnar fracture, and intertarsal joint swelling were present. Results of hematologic testing and biochemical analysis revealed severe leukocytosis with heterophilia and increased creatine kinase and aspartate aminotransferase activities consistent with musculoskeletal lesions. Radiographs confirmed a right humeral fracture and showed severe polyostotic lytic and expansile lesions of the appendicular skeleton, as well as an enlarged hepatic silhouette. Surgical repair of the fracture was attempted, but the bird died during the procedure. Postmortem examination revealed severe bone deformities involving the fractured humerus, both ulnas, and the left tibiotarsus. Histologic findings were consistent with multiple intraosseous lipomas of the long bones and severe hepatic lipidosis. To our knowledge, this is the first report of multiple intraosseous lipomas in a bird.

From humans to hydra: patterns of cancer across the tree of life

Cancer is a disease of multicellularity; it originates when cells become dysregulated due to mutations and grow out of control, invading other tissues and provoking discomfort, disability, and eventually death. Human life expectancy has greatly increased in the last two centuries, and consequently so has the incidence of cancer. However, how cancer patterns in humans compare to those of other species remains largely unknown. In this review, we search for clues about cancer and its evolutionary underpinnings across the tree of life. We discuss data from a wide range of species, drawing comparisons with humans when adequate, and interpret our findings from an evolutionary perspective. We conclude that certain cancers are uniquely common in humans, such as lung, prostate, and testicular cancer; while others are common across many species. Lymphomas appear in almost every animal analysed, including in young animals, which may be related to pathogens imposing selection on the immune system. Cancers unique to humans may be due to our modern environment or may be evolutionary accidents: random events in the evolution of our species. Finally, we find that cancer‐resistant animals such as whales and mole‐rats have evolved cellular mechanisms that help them avoid neoplasia, and we argue that there are multiple natural routes to cancer resistance.

Galliformes and Columbiformes

Galliformes and columbifomes are closely associated with humans and some species have been domesticated for well over 5000 years. Both orders remain diverse, ranging from the common domestic poultry species (e.g., chicken, turkey, and squabs) to the more exotic species found in the wild and in zoological collections. While many species have been benefited from human activities and have increased their ranges, others have declined in numbers and some have become threatened (e.g., Trinidad piping-guan and wood quail) or even extinct (e.g., dodo and passenger pigeon). Nondomestic galliformes and columbiformes are susceptible to many of the same diseases that occur in domestic species, yet predisposition may be different. Furthermore, disease prevalence depends on exposure and potential risk factors. Infectious diseases that tend to be more common under intensive commercial production may not pose as great a risk to exotic and free-living species.

External Beam Radiation Therapy of Squamous Cell Carcinoma in the Beak of an African Grey Parrot (Psittacus timneh)

Squamous cell carcinoma has been reported in a variety of bird species, most commonly psittacine and gallinaceous birds. The long-term prognosis in nongallinaceous birds is generally poor if complete surgical excision is not possible. Squamous cell carcinoma of the rhinotheca was diagnosed in a 34-year-old timneh African grey parrot (Psittacus timneh) with a 2-year history of beak abnormalities. No evidence of metastasis or local invasion were found on results of radiographs or computed tomography scan. The bird was treated with surgical debulking and palliative megavoltage radiation therapy. After 4 radiation treatments, the affected tissue was necrotic and was debrided to reveal healthy granulation tissue. The bird died approximately 7 months after diagnosis and 4 months after cessation of radiation treatment. At the time of death, a small scab lesion remained at the left oral commissure, but no visible tumor regrowth was evident. A postmortem examination was not performed, however, and tumor recurrence could not be ruled out in this bird.

Avian Oncology: Diseases, Diagnostics, and Therapeutics

Companion birds are increasingly living longer due to improved husbandry, nutrition, and veterinary care. As a consequence, a growing number of geriatric disease conditions are diagnosed and managed by veterinarians. Awareness of bird owners of diagnostic and treatment options for neoplastic diseases in humans and domestic animals has led to increasing demand to provide advanced diagnostic and treatment modalities for companion birds diagnosed with neoplasia. Treatment remains challenging in many companion birds due to the lack of information regarding prognosis and efficacy of antineoplastic treatments in these species. There is no established standard of care for most tumors in companion birds.

A 5-Year Retrospective Review of Avian Diseases Diagnosed at the Department of Pathology, University of Georgia

Avian samples (n = 827) submitted to the University of Georgia from 2006 to 2011 were reviewed to determine common disease entities and taxa-specific patterns. The study included 153 species, with 64.5% Psittaciformes, 11.3% Passeriformes, 7.9% Galliformes, 3.8% Columbiformes and 3.5% Anseriformes. Infectious agents were identified in 226 birds (27.3%); bacterial infections (n = 119; 14.4%) were most commonly gram-negative bacilli and Chlamydia psittaci and less commonly Mycoplasma and Mycobacterium spp. Mycotic infections (e.g. Aspergillus spp., Candida spp.) were identified in 66 birds (7.9%), followed by viruses in 30 birds (3.6%), most commonly polyomavirus and poxviruses. Eighteen birds had macroparasite infections, which were most common in Galliformes and most often involved gastrointestinal Capillaria spp. Neoplasia was diagnosed in 76 birds (9.2%) of 25 species, with 79% of the tumours deemed to be malignant. The most common neoplasm was lymphoma (n = 17; 22.4%), which was diagnosed in Psittaciformes, Galliformes and Passeriformes. Adenocarcinoma (n = 9) was found most frequently in the reproductive and gastrointestinal tracts. Haematopoietic neoplasms included myelocytoma and erythroid leucosis. Atherosclerosis was most common in psittacines (23/32; 71.8%) and in raptors and aquatic birds. Seventeen birds, mostly psittacines and aquatic birds, had amyloidosis, most often in the liver, kidney and spleen. Twenty-two birds had gout, most commonly the visceral form. Overall, bacterial infection was the most frequently diagnosed cause of death in captive birds, most commonly in Psittaciformes, followed by Passeriformes and Galliformes. Neoplasia was most common in Psittaciformes, which generally are longer lived than other taxa studied. Some disease entities (e.g. atherosclerosis and aspergillosis) may be associated with captive conditions, and some may involve a genetic predisposition (e.g. atherosclerosis, amyloidosis and haemosiderosis).

Polyostotic Chondroblastic Osteosarcoma in a Kestrel ( Falco tinnunculus )

We report a case of polyostotic chondroblastic osteosarcoma in a kestrel ( Falco tinnunculus ) admitted to the Wildlife Rehabilitation and Rescue Center (Naples, Italy). A consolidated fracture of the left tibiotarsus bone and a deviation of the limb were evident. After radiographic, cytologic, and histopathologic examinations, a diagnosis of polyostotic chondroblastic osteosarcoma was made. To our knowledge, this is the first report on polyostotic chondroblastic osteosarcoma in a kestrel.

Prevalence of Neoplastic Diseases in Pet Birds Referred for Surgical Procedures

Neoplastic disease is common in pet birds, particularly in psittacines, and treatment should be primarily aimed at tumor eradication. Nineteen cases of pet birds submitted to diagnostic and/or therapeutic surgical procedures due to neoplastic disease characterized by the presence of visible masses were retrospectively analyzed; affected species, types of neoplasms and respective locations, and outcomes of surgical procedures were determined. All birds undergoing surgery belonged to the order Psittaciformes; the Blue-fronted parrot (Amazona aestiva) was the prevalent species. Lipoma was the most frequent neoplasm in the sample studied. Most neoplasms affected the integumentary system, particularly the pericloacal area. Tumor resection was the most common surgical procedure performed, with high resolution and low recurrence rates.

Comparative Pharmacokinetics and Allometric Scaling of Carboplatin in Different Avian Species

The use of chemotherapeutics as a possible treatment strategy in avian oncology is steadily increasing over the last years. Despite this, literature reports regarding dosing strategies and pharmacokinetic behaviour of chemotherapeutics in avian species are lacking. The aim of the present study was to investigate the pharmacokinetics of carboplatin in a representative species of the order of Galliformes, Anseriformes, Columbiformes and Psittaciformes. Eight chickens, ducks and pigeons and twenty-eight parakeets were administered carboplatin intravenously (5 mg/kg body weight). A specific and sensitive liquid chromatography-tandem mass spectrometry method was developed and validated for quantification of the free carboplatin in plasma of the four birds species (limit of quantification: 20 ng/mL for chicken and duck, 50 ng/mL for pigeon and 100 ng/mL for parakeets). Non-compartmental pharmacokinetic analysis and allometric scaling demonstrated a significant correlation (R² = 0.9769) between body weight (BW) and elimination half-life (T1/2el). T1/2el ranged from 0.41 h in parakeets (BW: 61 ± 8 g) to 1.16 h chickens (BW: 1909 ± 619 g). T1/2el is a good parameter for dose optimization of carboplatin in other avian species, since also the previously reported T1/2el in cockatoos (average BW: 769 ± 68 g) of 1.00 h corresponds to the results obtained in the present study.

Use of 3D Ultrasonography in Diagnosing Ovarian Adenocarcinoma in a Common Mynah ( Acridotheres tristis )

A 12-year-old female common mynah ( Acridotheres tristis ) was examined because of dyspnea and coelomic enlargement. Abdominal radiographs revealed hepatomegaly and a coelomic mass of unknown origin. Both brightness mode (2-dimensional; 2D) and 3-dimensional (3D) ultrasonography were performed to identify the origin of the mass. Ultrasonographic findings distinguished the mass from the liver and revealed high vascularization of the mass and a moderate increase in echogenicity of the liver. Three-dimensional ultrasonographic histogram analysis of the mass was performed. The mynah was treated with supportive care but died after 3 days. Histopathologic examination showed ovarian adenocarcinoma, with concurrent mild to moderate hepatopathy. In diagnostic imaging using ultrasound in birds, 3D ultrasonography allows perspective images of the internal organs to be obtained and is potentially superior to 2D ultrasonography in evaluating irregularly shaped objects.

Bilateral Malignant Seminomas in Two Unrelated, Aged Trumpeter Hornbills (Bycanistes buccinator)

Seminomas occur infrequently in birds. Two cases of bilateral malignant seminomas in unrelated trumpeter hornbills (Bycanistes buccinator) are described. Case 1 was a 22-year-old trumpeter hornbill submitted for necropsy because of sudden death at a zoo in California. Postmortem examination revealed multiple masses within the body cavity, 2 of which replaced both testes. Case 2 was a 19-year-old trumpeter hornbill at a zoo in North Carolina that underwent exploratory surgery for a suspected gastrointestinal obstruction. Both testes were diffusely enlarged, compressing and replacing the adjacent kidneys. In both birds, the masses were composed of discrete, round to polyhedral cells, typical of seminomas. Examination of the ancestry of the hornbills showed they were unrelated to each other, suggesting a potential predisposition for these birds to develop seminomas.

Branchial Cyst With Carcinoma in an Umbrella Cockatoo (Cacatua alba)

A 16-year-old female umbrella cockatoo (Cacatua alba) was presented for a fluctuant, right-sided cervical mass that extended from the caudolateral edge of the right mandible to the coelomic inlet. Results of initial diagnostic tests were consistent with a cystic mass containing hemorrhage. Surgical exploration and removal of the mass was done, but because the hyoid apparatus was incorporated in the base of the cyst, complete surgical excision was not possible. Histopathologic results were consistent with a branchial cyst with carcinoma. Five months after surgery, the cockatoo exhibited intermittent periorbital swelling and epistaxis, and cytologic results of a fluid aspirate from the right infraorbital sinus were consistent with carcinoma. Results of magnetic resonance imaging revealed extensive abnormal T2 and short-tau inversion-recovery hyperintense tissue associated with the right side of the head and neck, infiltrating between muscle planes and extending into the right retro-orbital tissue and nasal cavity. At 7 months after surgery, the bird was severely dyspneic and was euthanatized. To our knowledge, this is the first report describing the diagnosis, management, and histologic characteristics associated with a branchial cyst with carcinoma in an animal.

Osteosarcoma of the tibiotarsus with possible pulmonary metastasis in a ring-necked dove (Streptopelia risoria)

An unknown-age, adult female ring-necked dove (Streptopelia risoria) was presented with an ulcerated mass on the medial side of the right tibiotarsus. Radiographs revealed severe boney lysis with proliferative periosteal reaction. Surgical amputation was performed at the level of the mid femur and histopathologic examination of the mass identified an osteosarcoma. At the 6-month recheck, the bird was in good condition with no evidence of tumor regrowth or metastasis; however, at 8 months, the dove was found dead. On necropsy, a large mass was present in the coelomic cavity invading the left pulmonary parenchyma. Histopathologic examination indicated a spindle cell sarcoma. Immunohistochemical staining for osteocalcin and osteonectin was performed on the confirmed osteosarcoma in the tibiotarsus and the spindle cell sarcoma mass. Results indicated positive intracytoplasmic immunoreactivity for osteocalcin and osteonectin in the confirmed osteosarcoma neoplasm. Very rare positive cytoplasmic immunoreactivity occurred in the spindle cell sarcoma.

Intraocular osteosarcoma in an Umbrella Cockatoo (Cacatua alba)

An adult, presumed intact female Umbrella Cockatoo (Cacatua alba), presented with acute hemorrhage from an intraocular mass that perforated through the right cornea. Computed tomography scanning revealed a large soft tissue mass in the right orbit, invading and displacing the globe laterally, and destroying the scleral ossicles. There was no evidence of bony changes of the orbit or extension of the mass into the optic nerve or brain. Exenteration and mass removal were performed, and osteosarcoma was diagnosed via histopathology. Radiotherapy was delivered with an orthovoltage unit to a total dose of 68 Gray delivered in 17 fractions over 6 weeks. The bird recovered well from treatment, but died 2 months after the last radiation session with neurological signs. Necropsy was not performed. To our knowledge, this is the first case of an intraocular osteosarcoma reported in a bird, and the first case of attempted treatment of osteosarcoma in a bird by a combination of surgery and radiation therapy.

Multidrug-resistant bacterial ingluvitis associated with squamous cell carcinoma in a budgerigar (Melopsittacus undulatus)

A 2-year-old budgerigar (Melopsittacus undulatus) was presented to the Massey University Veterinary Teaching Hospital for chronic regurgitation. Multiple drug-resistant Klebsiella oxytoca was cultured from the crop. Necropsy revealed a mass in the crop that was histologically diagnosed as squamous cell carcinoma (SCC). To the authors' knowledge, this is the first report of SCC in a budgerigar associated with a multidrug-resistant bacterial ingluvitis.

Clinical approach to renal neoplasia in budgerigars (Melopsittacus undulatus)

Renal neoplasia in budgerigars (Melopsittacus undulatus) is seen regularly in general practice and is of interest to many practicing veterinary surgeons. This review article provides an overview of the current knowledge and the most recent reports in avian literature regarding renal tumours in budgerigars, with the emphasis on clinical diagnosis and treatment. The high prevalence of renal neoplasia in budgerigar is discussed, with notes on the most commonly diagnosed tumours, possibility of metastases, sex and age predisposition. The possibility of ultrasonography and radiography in the diagnosis of this pathological condition are compared as well as the possible role of blood and urine analyses. Two studies are described, both of which investigate the possible involvement of a retrovirus as the aetiological agent.

Resection and use of a cyclooxygenase-2 inhibitor for treatment of pancreatic adenocarcinoma in a cockatiel

CASE DESCRIPTION

A 5-year-old sexually intact male cockatiel was examined because of progressive dyspnea of 1 week's duration.

CLINICAL FINDINGS

On auscultation of the lungs and air sacs, crackles were detected; the abdomen was distended and fluctuant on palpation. Eleven milliliters of clear yellow fluid was collected via abdominocentesis. Radiography (with and without contrast medium) and ultrasonography revealed a soft tissue mass in the caudoventral portion of the coelom.

TREATMENT AND OUTCOME

Exploratory surgery of the coelomic cavity was performed and the neoplasm was excised. Histologic examination of the neoplasm was consistent with a high-grade pancreatic exocrine adenocarcinoma. Celecoxib, a cyclooxygenase (COX)-2 inhibitor, was administered for pain management and for potential antineoplastic activity. For 4.5 months after surgery, the bird had no recurrence of clinical signs; however, dyspnea recurred and during evaluation, the bird died. Necropsy findings indicated that the pancreatic adenocarcinoma had metastasized to surrounding tissues and vessels, which was not unexpected given the high grade assigned to the neoplasm during histologic analysis.

CLINICAL RELEVANCE

Pancreatic neoplasms are associated with a poor prognosis, regardless of treatment modality. Celecoxib can be administered as palliative treatment to affected birds, but as with any nonsteroidal anti-inflammatory drug, COX-2 inhibitors should be used cautiously because they can adversely affect renal function by decreasing renal prostaglandin synthesis.

Doxorubicin pharmacokinetics following a single-dose infusion to sulphur-crested cockatoos (Cacatua galerita)

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 (i.v.) 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 i.v. 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 (beta-phase) half-life was 41.4 +/- 18.5 min, the systemic clearance (CI) 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 (V(SS)) was 238 +/- 131 mL/kg. The extrapolated area under the curve (AUC(0-infinity)) was 950 +/- 677 ng/mL x 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.