Pharmacokinetics of Cannabidiol in the Hispaniolan Amazon Parrot (Amazona ventralis).

The purpose of this study was to determine the pharmacokinetics of cannabidiol (CBD), a potential treatment option that may alleviate pain in companion animals and humans, in the Hispaniolan Amazon parrot (Amazona ventralis). A pilot study administered a single oral dose of CBD in hemp oil at 10 mg/kg to 2 birds and 20 mg/kg to 2 birds. Because the maximum serum concentrations (Cmax) for these doses were 5.5 and 13 ng/mL, respectively, and the serum half-life was 2 hours for both groups, the doses were considered too low for clinical use in this species. Therefore, a study was designed in which 14 healthy 12-14-year-old parrots of both sexes and weighing 0.24-0.35 kg (mean, 0.28 kg) were enrolled. Seven birds were administered 60 mg/kg CBD PO, and 7 birds were administered 120 mg/kg CBD PO. Blood samples were obtained at time 0, and at 0.5, 1, 2, 3, 4, 6, and 10 hours posttreatment in a balanced incomplete block design. Quantification of plasma CBD concentrations was determined by use of a validated liquid chromatography-mass spectrometry assay. Pharmacokinetic parameters were determined by noncompartmental analysis. The areas under the curve (h·ng/mL) were 518 and 1863, Cmax (ng/ mL) were 213 and 562, and times to achieve Cmax (hours) were 0.5 and 4 for the 60 and 120 mg/kg doses, respectively. The serum half-life could not be determined in the 60 mg/kg treatment, but was 1.28 hours at 120 mg/kg. Adverse effects were not observed in any bird. The highly variable results and short half-life of the drug in Hispaniolan Amazon parrots, even at high doses, suggests that this drug formulation was inconsistent in achieving targeted concentrations as reported in other animal species.

Pilot Study of a Single Dose of Orally Administered Tapentadol Suspension in Hispaniolan Amazon Parrots (Amazona ventralis).

Tapentadol is an analgesic agent that acts as both a µ-opioid receptor agonist and a norepinephrine reuptake inhibitor. It is a common therapeutic agent in human medicine for management of acute and chronic pain, and it is currently being investigated for use in veterinary medicine. Tapentadol was evaluated in Hispaniolan Amazon parrots (Amazona ventralis) because there is only 1 other oral opioid-like analgesic agent, tramadol, which has been evaluated in an avian species. The effectiveness of tramadol after administration to a patient involves a complex physiologic metabolism and has been found to have variable pharmacokinetics between species. Because of the lack of active metabolites from tapentadol, less interspecific variation was expected. Seven Hispaniolan Amazon parrots were used to evaluate the pharmacokinetics of tapentadol after a single 30 mg/kg PO administration of a compounded 5 mg/mL tapentadol suspension. Blood samples were collected before (time 0) and 0.25, 0.5, 0.75, 1, 1.5, 3, and 6 hours after administration, following a balanced, incomplete-block design. Plasma tapentadol concentrations were measured by high-pressure liquid chromatography with mass spectrometry. Results revealed detectable plasma concentrations in only 2 of 7 birds (29%), and the bird with the highest plasma levels had a peak concentration (Cmax) of 143 ng/mL and a half-life (T 1/2) of 24.8 minutes. The variable plasma concentrations and short half-life of this drug in Hispaniolan Amazon parrots suggests that this drug would be of limited clinical use in this species; however, it is possible that this drug will be more bioavailable in other avian species.

PHARMACOKINETICS OF ORAL MAVACOXIB IN CARIBBEAN FLAMINGOS (PHOENICOPTERUS RUBER RUBER).

Mavacoxib is a selective cyclooxygenase-2 nonsteroidal anti-inflammatory drug that has been used for management of osteoarthritis and other inflammatory conditions in dogs. The main advantage of mavacoxib over other nonsteroidal anti-inflammatory drugs is its longer plasma half-life, leading to decreased dosing frequency. This study determined the pharmacokinetics of mavacoxib in Caribbean flamingos (Phoenicopterus ruber ruber) after a single-dose oral administration of 6 mg/kg (n = 6). Plasma mavacoxib concentrations were determined using liquid chromatography with mass spectrometry, and pharmacokinetic analysis was performed using noncompartmental methods. Mean peak plasma concentration (Cmax) was (mean; range) 2.97 (2.19--4.06) µg/ml; mean time to peak plasma concentration (Tmax) was 18.68 (4.00-48.00) hr; mean area under the curve (AUC) was 455 (292-637) hr * µg/ml; and mean terminal half-life (T1/2) was 74.47 (49.57-161.43) hr. Based on the results of this study, mavacoxib dosed at 6 mg/kg orally in Caribbean flamingos reaches plasma concentrations above the therapeutic concentration established for dogs, but further studies are needed to determine appropriate dosing recommendations in flamingos.

Surgical Management of an Intrathoracic Branchial Cyst in a Yellow-crested Cockatoo (Cacatua sulphurea).

A 40-year-old, female lesser crested cockatoo (Cacatua sulphurea) was presented with a complaint of hyporexia and sudden onset of sneezing and wheezing. Physical examination revealed mild stertorous inhalation, and the apex of the heart was palpable caudoventral to the distal tip of the sternum. Projection radiographic images showed a soft tissue mass displacing the heart and the thoracic portion of the trachea. A subsequent computed tomography series revealed a single, large, and predominantly encapsulated soft-tissue mass. The mass was contained within the cranial thoracic region and occupied most of the anatomic location of the thoracic portion of the clavicular air sac, extending around a portion of the trachea. A surgical exploratory procedure was performed, with a thoracic inlet thoracotomy, and the mass was found to be cystic and deeply attached to surrounding tissues at its caudal-most aspect. Complete excision was not possible, and the mass was drained and an incomplete resection was accomplished with approximately one-half of the cystic structure removed and submitted for histopathology. The mass was found to be benign, epithelial-lined, dense, fibrous connective tissue that would be consistent with a branchial cyst.

PHARMACOKINETICS OF ORAL GABAPENTIN IN CARIBBEAN FLAMINGOS ( PHOENICOPTERUS RUBER RUBER).

Gabapentin is a first-line treatment for neuropathic pain and adjunct anticonvulsant medication in humans and other species. Gabapentin may have advantages over other analgesics because of its broad therapeutic range with limited adverse effects and wide availability as an oral formulation. This study determined the pharmacokinetics of gabapentin in Caribbean flamingos ( Phoenicopterus ruber ruber) after a single-dose oral administration of either 15 mg/kg ( n = 6) or 25 mg/kg ( n = 6). Plasma gabapentin concentrations were determined using liquid chromatography with mass spectrometry, and pharmacokinetic analysis was performed using noncompartmental methods. Respectively for the 15 mg/kg and 25 mg/kg dose, mean peak plasma concentration ( Cmax) was (mean ± pseudo SD) 13.23 ± 1.47 and 24.48 ± 5.81 µg/ml; mean time to peak plasma concentration ( Tmax) was 0.50 ± 0.24 and 0.56 ± 0.28 hr; mean area under the curve (AUC) was 76.0 ± 26.3 and 114.7 ± 27.5 hr·µg/ml; and mean terminal half-life ( T1/2) was 3.39 ± 0.90 and 4.46 ± 1.12 hr. Based on the results of this study, gabapentin dosed at 25 mg/kg orally in most Caribbean flamingos is likely to maintain plasma concentrations above the therapeutic range established for humans for approximately 12 hr.

PHARMACOKINETICS OF A SINGLE DOSE OF ORAL AND SUBCUTANEOUS ENROFLOXACIN IN CARIBBEAN FLAMINGOS (PHOENICOPTERUS RUBER RUBER).

Enrofloxacin is a fluoroquinolone antimicrobial that is widely used in veterinary medicine because of its bactericidal activity and safety in a broad range of species. Caribbean flamingos, a member of the order Phoenicopteriformes, are popular in zoological collections and suffer from a variety of conditions that can result from or lead to bacterial infection. In this study, two groups of 7 adult captive Caribbean flamingos received a single dose of 15 mg/kg enrofloxacin, administered either orally or subcutaneously. Plasma concentrations of enrofloxacin and its metabolite, ciprofloxacin, were measured using liquid chromatography and mass spectrometry. Pharmacokinetic analysis was performed using noncompartmental methods. The pharmacokinetic parameters for both routes of administration were similar, with a mean peak plasma concentration (Cmax) of 5.25 and 5.77 µg/ml, a mean time to peak plasma concentration (Tmax) of 1.49 and 1.1 hr, a mean area under the curve (AUC) of 49.9 and 47.3 hr·µg/ml, and a mean terminal half-life (t1/2) of 5.83 and 6.46 hr for oral and subcutaneous dosing, respectively. Conversion to ciprofloxacin was minimal, with the AUC of ciprofloxacin representing <3% of the enrofloxacin AUC for both routes of administration. Based on the results of the present study, a dose of 15 mg/kg enrofloxacin delivered either orally or subcutaneously in the Caribbean flamingo every 24 hr is recommended for susceptible bacterial pathogens with a minimal inhibitory concentration ≤ 0.25 µg/ml.

DIAGNOSIS AND SUCCESSFUL TREATMENT OF A POTENTIALLY ZOONOTIC DERMATOPHYTOSIS CAUSED BY MICROSPORUM GYPSEUM IN A ZOO-HOUSED NORTH AMERICAN PORCUPINE (ERETHIZON DORSATUM).

A female North American porcupine ( Erethizon dorsatum ) was evaluated for a unilateral pedal crusting and alopecic dermatopathy. Fungal culture and histopathology testing revealed Microsporum gypseum dermatophytosis. Treatment with topical miconazole was initiated and then discontinued after 9 days and changed to oral terbinafine. Twenty-eight days after initial examination, clinical signs were improving, and fungal cultures of the front foot, muzzle, and noninfected area along the dorsum were negative for M. gypseum. Visual exams were conducted on a regular basis. Eighty-three days after initial evaluation, clinical signs had completely resolved and repeat fungal cultures were negative. One of the animal's keepers was suspected to have acquired a dermal fungal infection 3 days after contact with this porcupine, and lesions had resolved after treatment with topical ketoconazole. To the authors' knowledge, this is the first report of M. gypseum diagnosed and treated in a captive North American porcupine. Veterinary staff and zookeepers should be aware of this potentially zoonotic infection.

Mucoepidermoid Carcinoma in the Skull of an Orange-winged Amazon Parrot (Amazona amazonica).

A 33-year-old female intact orange-winged Amazon parrot (Amazona amazonica) presented for a slowly growing mass over the right eye. A computed tomography scan performed with and without intravenous contrast revealed a heterogeneous mixed soft tissue and mineral-dense mass with a small area of non-contrast-enhancing fluid density located between the orbits at the caudal aspect of the nasal passages, with associated lysis of the right caudal nasal passage and the right frontal bone. Following euthanasia, the mass was found to consist of soft tissue between the right eye and nostril over the right frontal bone. Lysis of the underlying bone resulted in a bony defect leading into the infraorbital sinus along the dorsorostral aspect of the right eye. Histopathology revealed an unencapsulated, poorly demarcated, highly cellular neoplasm composed of islands and trabeculae of neoplastic cells embedded in abundant loose fibrovascular stroma which completely obliterated the cortical bone and sinuses of the rostral skull and infiltrated the surrounding muscle and soft tissue. Histologically, the tumor was consistent with a high-grade mucoepidermoid carcinoma, characterized by the presence of epidermoid, intermediate, and mucous-producing cell types. No evidence of metastasis was identified. The tissue of origin was suspected to be salivary or nasal mucous glands, but was difficult to confirm due to distortion of normal tissue architecture as a result of the tumor. Although mucoepidermoid carcinomas are a common salivary gland tumor in human medicine, they are not well recognized in avian species, and no specific case reports exist describing this pathology in an Amazon parrot. Despite the lack of distinct salivary glands in most avian species, mucoepidermoid carcinomas can occur, can cause significant clinical disease, and should be included as a differential diagnosis for avian patients presenting with similar lesions.

Single-Dose Pharmacokinetics of Piperacillin/Tazobactam in Hispaniolan Amazon Parrots ( Amazona ventralis ).

To determine the pharmacokinetics of piperacillin/tazobactam in Hispaniolan Amazon parrots ( Amazona ventralis ), 8 healthy adult parrots of both sexes were used in a 2-part study. In a pilot study, piperacillin (87 mg/kg) in combination with tazobactam (11 mg/kg) was administered intramuscularly (IM) to 2 birds, and blood samples were obtained at 0, 0.5, 1, 1.5, 2, 3, 4, 6, 8, and 10 hours after administration. Based on the results obtained, a main study was done in which piperacillin/tazobactam was administered at 2 different doses. In 3 birds, the initial dose of piperacillin (87 mg/kg)/tazobactam (11 mg/kg) IM was administered, and in 3 birds, the dose was doubled to piperacillin (174 mg/kg)/tazobactam (22 mg/kg) IM. In all 6 birds, blood samples were obtained at 0, 5, 15, and 30 minutes and at 1, 1.5, 2, 2.5, 3, and 4 hours after administration. Quantification of plasma piperacillin and tazobactam concentrations was determined by validated liquid chromatography-mass spectrometry assay. Pharmacokinetic parameters were determined by noncompartmental analysis. After intramuscular administration, the mean ± standard error values of T1/2 (h) was 0.52 ± 0.05 and 0.32 ± 0.07, Tmax (h) was 0.28 ± 0.09 and 0.25 ± 0.10, Cmax (µg/mL) was 86.34 ± 20.62 and 9.03 ± 2.88, and Cmax/dose was 0.99 ± 0.24 and 0.83 ± 0.26 for piperacillin (87 mg/kg) and tazobactam (11 mg/kg), respectively. When the doses were doubled, the T1/2 (h) was 0.65 ± 0.08 and 0.34 ± 0.02, Tmax (h) was 0.28 ± 0.12 and 0.14 ± 0.06, Cmax (µg/mL) was 233.0 ± 6.08 and 22.13 ± 2.35, and Cmax/dose was 1.34 ± 0.03 and 1.02 ± 0.11 for piperacillin and tazobactam, respectively. Results indicate that piperacillin is rapidly absorbed and reaches high initial concentrations; however, it is also rapidly eliminated in the Hispaniolan Amazon parrot, and tazobactam has similar pharmacokinetics as piperacillin. Administration of piperacillin at 87 mg/kg IM q3-4h is recommended for this species to control infections attributed to susceptible bacteria with a minimum inhibitory concentration of ≤4 µg/mL.

MANAGEMENT OF ENDOMETRIOSIS IN TWO CAPTIVE MANDRILLS (MANDRILLUS SPHINX).

Endometriosis has been reported in humans, great apes, and Old World monkeys. Although cases are noted anecdotally in Mandrillus spp., and a previously reported case was noted on postmortem examination, to the authors' knowledge, no previous reports of case management have been published in the peer-reviewed literature. This paper describes the medical and surgical management of endometriosis in two mandrills (Mandrillus sphinx).

Pharmacokinetics of a Single Dose of Oral and Subcutaneous Meloxicam in Caribbean Flamingos ( Phoenicopterus ruber ruber).

To determine the pharmacokinetics of meloxicam in Caribbean flamingos ( Phoenicopterus ruber ruber), a pilot study was performed first, followed by a complete pharmacokinetic study. Four healthy birds were divided into 2 groups and administered 1 mg/kg of either oral (n = 2) or subcutaneous (n = 2) meloxicam. Plasma meloxicam concentrations were determined with liquid chromatography-mass spectrometry. Based on the pilot study results, 12 healthy birds were assigned into 2 groups and administered either 3 mg/kg PO (n = 6) or 1.5 mg/kg SC (n = 6) of meloxicam. Blood samples were collected at baseline and at 9 time intervals per group after administration of meloxicam in all flamingos. Plasma concentrations after administration of 3 mg/kg PO meloxicam reached a mean maximum plasma concentration of 1.449 µg/mL at 2.35 hours with a terminal half-life of 1.832 hours. After administration of 1.5 mg/kg SC meloxicam, maximum plasma concentration was 4.059 µg/mL at 0.91 hour with a terminal half-life of 1.104 hours. The plasma profile from the main oral study (3 mg/kg PO) differed markedly from the pilot study (1 mg/kg PO), suggesting a delayed absorption with the higher dose and lack of dose proportionality. The different doses for subcutaneous administration resulted in a proportional change in plasma concentrations. Further studies are needed to evaluate the effects of the drug volume administered and fasting status when oral dosing is used. Future studies are also needed to investigate multiple-dose pharmacokinetics of meloxicam and to determine the therapeutic meloxicam plasma concentration in Caribbean flamingos.

Malignant Melanoma of the Syrinx and Liver in an African Grey Parrot ( Psittacus erithacus erithacus).

A 20-year-old, female African grey parrot ( Psittacus erithacus erithacus) was examined because of ataxia and weakness. Radiographs were unremarkable, and results of a complete blood cell count revealed leukocytosis and heterophilia. Because of poor response to therapy with meloxicam, doxycycline, and enrofloxacin; deteriorating condition; and poor prognosis, the parrot was euthanatized. Postmortem examination revealed 2 dark red nodules in the liver. No grossly visible mass was observed in the syrinx. Histologic examination of the liver and syrinx revealed similar foci of round, oval, and polygonal cells exhibiting severe pleomorphism, with poorly demarcated cytoplasmic borders and moderate amounts of eosinophilic cytoplasm containing brown to black granules (melanin). The mitotic index was 15. The presence of melanin pigment is consistent with a diagnosis of melanoma at both sites. The multifocal distribution and intravascular invasion indicate metastasis; however, the site of origin was unknown. To our knowledge, this is the first recorded case of melanoma in an avian syrinx.

SMALL INTESTINAL ADENOCARCINOMA WITH CARCINOMATOSIS IN A SWIFT FOX (VULPES VELOX).

A 7-yr-old, intact, female swift fox (Vulpes velox) presented to the Veterinary Health Center at Kansas State University with a history of chronic weight loss, lethargy, inappetence, and myiasis. On physical examination, a firm mass was palpated in the mid- to cranial abdomen. The fox was euthanatized as a result of the grave prognosis. Gross necropsy and histologic findings included a small intestinal adenocarcinoma with diffuse transperitoneal spread throughout the abdominal cavity (carcinomatosis). To the authors' knowledge, this is the first report of intestinal adenocarcinoma with carcinomatosis in a swift fox.

MULTICENTRIC T-CELL LYMPHOMA AND CUTANEOUS HEMANGIOSARCOMA IN A CAPTIVE CHEETAH (ACINONYX JUBATUS).

A 13-yr-old intact male cheetah (Acinonyx jubatus) presented for evaluation after a 4-mo history of intermittent lethargy and increased expiratory effort. The clinical signs were initially noted after the diagnosis and death of its 13-yr-old male sibling with solitary hepatic T-cell lymphoma. Physical examination findings included thin body condition, harsh lung sounds, peripheral lymphadenopathy, and a cutaneous mass on the right medial tarsus and scrotum. Excisional biopsies diagnosed well-differentiated cutaneous hemangiosarcomas. Thoracic radiographs revealed a cranial mediastinal mass. Complete blood count and serum biochemical analyses showed a leukocytosis with persistent lymphocytosis, progressive azotemia, and markedly elevated alkaline phosphatase. Because of the cheetah's declining quality of life, euthanasia was elected. Postmortem examination, histopathology, and immunohistochemical staining revealed multicentric T-cell lymphoma. Feline leukemia virus (FeLV) enzyme-linked immunosorbent assay, FeLV polymerase chain reaction (whole blood), and viral metagenomic analysis were negative. This is the first case of cutaneous hemangiosarcoma and multicentric T-cell lymphoma reported in a FeLV-negative cheetah.

SOLITARY T-CELL HEPATIC LYMPHOMA WITH LARGE GRANULAR LYMPHOCYTE MORPHOLOGY IN A CAPTIVE CHEETAH (ACINONYX JUBATUS).

A 13-yr-old male cheetah (Acinonyx jubatus) presented for an acute history of lateral recumbency and anorexia. Upon physical examination under general anesthesia, severe icterus was noted. A serum biochemical profile confirmed markedly elevated total bilirubin and alanine transaminase. Based on ultrasound-guided liver aspirates and cytology, a presumptive diagnosis of large granular lymphocyte hepatic lymphoma was reached. Abdominal and thoracic radiographs did not assist in reaching an antemortem diagnosis. Postmortem examination and histopathology provided a definitive diagnosis of hepatic lymphoma with acute massive hepatocelluar necrosis and hemorrhage, as well as concurrent lesions of gastric ulcers, ulcerative and sclerosing enteritis, myocardial hypertrophy, and splenic myelolipomas. Immunohistochemistry of the liver yielded CD-3 positive and CD-20 negative results, confirming lymphocytes of a T-cell lineage. Due to concern for possible retrovirus-associated disease, enzyme-linked immunosorbent assays for feline leukemia virus and feline immunodeficiency virus were performed retrospectively on a banked serum sample and yielded negative results, thus diminishing concern for the male conspecific housed in the same exhibit.

CUTANEOUS EPITHELIOTROPIC T-CELL LYMPHOMA WITH METASTASES IN A VIRGINIA OPOSSUM (DIDELPHIS VIRGINIANA).

A 2-yr-old, captive, intact female Virginia opossum ( Didelphis virginiana ) with a 7-mo history of ulcerative dermatitis and weight loss was euthanatized for progressive worsening of clinical signs. Initially the opossum was treated with several courses of antibiotics, both topically and systemically; systemic nonsteroidal anti-inflammatory medication; and, later, systemic glucocorticoids, with no improvement in clinical signs. Histopathologic samples of skin lesions taken 3 mo into the course of disease revealed no evidence of neoplasia; however, cytologic samples of a skin lesion taken 5 mo into the course of disease revealed mature lymphocytes, and were suggestive of cutaneous lymphoma. Postmortem histopathology revealed neoplastic cells consistent with lymphoma; these were found in the haired skin of the forearm, axilla, hind limb, face, and lateral body wall, as well as the liver, kidney, axillary lymph node, heart, and spleen. Multifocal neutrophilic and eosinophilic ulcerative and necrotizing dermatitis and folliculitis of the haired skin were also present. To the authors' knowledge, this is the first documented case of cutaneous lymphoma in a Virginia opossum and the first documented case with visceral metastases in a marsupial.

Ophthalmic Diagnostic Tests and Ocular Findings in a Flock of Captive American Flamingos ( Phoenicopterus ruber ruber).

Seventeen adult captive American flamingos ( Phoenicopterus ruber ruber) (34 eyes) underwent a complete ocular examination, including assessment of menace response, pupillary light reflexes, dazzle reflex, palpebral and corneal reflexes, fluorescein staining, slit-lamp biomicroscopy, and direct ophthalmoscopy. Birds were randomly assigned to one of 2 groups for tear production and intraocular pressure measurements. Tear production was measured by modified Schirmer tear test I (n = 9 birds) or phenol red thread test (n = 8 birds), and intraocular pressure was measured indirectly by applanation (Tonopen-XL) (n = 9 birds) or rebound (TonoVet) (n = 8 birds) tonometry. Conjunctival swab samples were taken from one randomly selected eye of all 17 birds to identify surface ocular microbial flora via aerobic bacterial culture. Additionally, 3 of the 17 birds were anesthetized for bilateral B-mode ocular ultrasonography examination to obtain axial globe measurements. Results showed that the menace response and dazzle reflex were absent in all birds. Sixteen of the 17 birds were free of significant ocular disease; a small cataract and pigment on the anterior lens capsule were noted in one eye of one bird. Mean ± SD tear production was 12.3 ± 4.5 mm/min (range, 4-20 mm/min) for modified Schirmer tear test I and 24.2 ± 4.4 mm/15 s (range, 14-30 mm/15 s) for phenol red thread test. Modified Schirmer tear test I measurements were significantly lower than phenol red thread measurements (P < .001). Mean intraocular pressure was 16.1 ± 4.2 mm Hg (range, 7-22 mm Hg) for Tonopen and 9.5 ± 1.7 mm Hg (range, 7-13 mm Hg) for TonoVet. Tonopen measurements were significantly higher than TonoVet measurements (P < .001). An Enterococcus species (9/17 eyes; 53%) and a gram-positive coccus (7/17 eyes; 41%) were the bacteria most commonly isolated from conjunctival swab samples. Mean B-mode ultrasonographic globe measurements of 6 eyes (3 birds) were axial globe length, 13.8 ± 0.16 mm; anterior chamber depth, 1.75 ± 0.05 mm; lens thickness, 4.6 ± 0.06 mm; vitreous body depth, 6.95 ± 0.10 mm; and pecten dimensions, 5.1 ± 0.38 mm length, 2.2 ± 0.14 mm width. In summary, the prevalence of ocular lesions was low in this population of captive American flamingos. Results obtained from 2 types of tear and intraocular pressure measurement tests were significantly different, indicating that a single type of each diagnostic test should be consistently used. A modification of the standard Schirmer tear test or use of phenol red thread test is recommended due to the small flamingo eye.

Nephrectomy in an Asian small-clawed otter (Amblonyx cinereus) with pyelonephritis and hydronephrosis secondary to ureteral obstruction.

A 10-yr-old, captive, intact male Asian small-clawed otter (Amblonyx cinereus) with a history of bilateral nephrolithiasis was presented for acute-onset lethargy and inappetance of 5 days duration. On physical examination, the otter was about 8% dehydrated and a palpable fluid wave was present in the abdomen. An abdominal ultrasound revealed hydronephrosis of the left kidney and a hyperechoic structure present within the lumen of the left ureter, causing an obstruction. A urinalysis revealed struvite crystalluria, bacteriuria, and an elevated pH. Following 4 days of antibiotic therapy, a left ureteronephrectomy was performed. Upon opening the kidney to retrieve calculi, a large amount of purulent material was noted within the renal pelvis. To the authors' knowledge, this is the first documented case of a nephrectomy in an Asian small-clawed otter. Nephrectomy should be considered as a viable option for treatment of ureteral obstruction, hydronephrosis, or severe pyelonephritis.