Metronomic Chemotherapy for Myxosarcoma Treatment in a Kori Bustard (Ardeotis kori).

A 22-year-old, wild-caught male kori bustard (Ardeotis kori) developed a large, slow-growing subcutaneous mass over the keel. The mass was surgically debulked and histopathologically described as a myxosarcoma. Surgical dehiscence and concurrent local tumor regrowth, with no evidence of metastasis, occurred over the subsequent 3 months, necessitating 2 additional surgical procedures to close the wound. At 19 weeks after the initial procedure, a second debulking surgical procedure was performed, at which time carboplatin-impregnated matrix beads were placed in the lesion. Moderate local tumor regrowth was clinically appreciable 4 weeks after surgery, at which time an oral metronomic chemotherapeutic protocol consisting of daily cyclophosphamide (10 mg/m(2)) and meloxicam (0.1 mg/kg) was initiated. Four months later, the tumor was no longer palpable. While oral therapy was discontinued during the breeding season, mass regrowth was observed, and the mass was surgically debulked before reinitiating oral chemotherapy. Treatment was extended for over 1 year with no hematologic evaluation or serum biochemical abnormalities, and the bird otherwise remained clinically healthy. To our knowledge, this is the first report of a myxosarcoma in a bustard species and the first report of successful clinical application of metronomic chemotherapy in an avian species.

Effects of a gonadotropin-releasing hormone vaccine on ovarian cyclicity and uterine morphology of an Asian elephant (Elephas maximus).

This report describes the successful use of a gonadotropin-releasing hormone (GnRH) vaccine to suppress ovarian steroidogenic activity and to treat hemorrhage and anemia associated with reproductive tract pathology in a 59-year-old Asian elephant (Elephas maximus). The Repro-BLOC GnRH vaccine was administered subcutaneously as a series of 4 boosters of increasing dose from 3 to 30 mg of recombinant ovalbumin-GnRH fusion protein given at variable intervals after initial vaccination with 3 mg protein. Efficacy was confirmed over a year after initial vaccination based on complete ovarian cycle suppression determined by serum progestagen analyses. Estrous cycle suppression was associated with a significant increase in GnRH antibody binding and subsequent decrease in serum luteinizing hormone and follicle-stimulating hormone concentrations. Ultrasonographic examinations of the reproductive tract documented a reduction in uterine size and vascularity after immunization. The hematocrit level normalized soon after the initial intrauterine hemorrhage, and no recurrence of anemia has been detected. No substantive adverse effects were associated with GnRH vaccination. The results indicate that GnRH vaccination in elephants shows potential for contraception and management of uterine pathology in older elephants.

Medical and surgical management of severe inflammation of the nictitating membrane in a Giant Panda (Ailuropoda melanoleuca).

A 10-year-old male giant panda (Ailuropoda melanoleuca) presented for severe, acute swelling and protrusion of the right nictitating membrane, unresponsive to topical therapy. Excisional biopsy of the nictitating membrane and its associated lacrimal gland was elected due to necrosis and friability of the tissue. Histopathology revealed suppurative, necrotizing conjunctivitis and dacryoadenitis. Culture grew Stenotrophomonas maltophila and Enterococcus spp with extensive antibiotic resistance. Treatment with topical and systemic antibiotics based on sensitivity results was initiated. All treatments were well tolerated. Healing was uncomplicated with no recurrence of the lesion and no clinical evidence of keratoconjunctivitis sicca. Ophthalmic exams and Schirmer tear tests performed opportunistically during postoperative anesthetic procedures were unremarkable, confirming that excision of the nictitating membrane had not caused clinically significant detrimental effects. The etiology of this lesion remains undetermined, but trauma is suspected. To the authors' knowledge, this is the first report of nictitating membrane pathology and excision in the giant panda.

Solitary Osteochondroma in a Ring-Tailed Lemur (Lemur catta).

A 20-y-old, male, ring-tailed lemur (Lemur catta) presented with a large, firm mass on the proximal caudolateral left femur. The animal displayed no clinical signs associated with the mass. Radiographs revealed a mineralized mass protruding from the femur, with an intact femoral cortex. Histopathology diagnosed osteochondroma in view of the presence of a peripheral layer of cartilage with progressive endochondral ossification and typical remodeling of bony trabeculae. The mass grew quickly after the initial biopsy, and a second surgery to debulk 95% of the tumor was performed. Histopathologic features of the larger samples were similar to those of the initial biopsies, with the cartilage layer being discontinuous and development of bone from some borders progressing directly from a periost-like layer. Nineteen months after the second surgery, the mass had regrown and extended further proximally on the femur toward the epiphysis, but the animal remained asymptomatic, and additional debulking was not attempted. This report is the first description of an osteochondroma in a prosimian and describes unique behavior of the tumor compared with osteochondromas found in humans, dogs, and cats.

Surgical correction of an arteriovenous fistula in a ring-tailed lemur (Lemur catta).

A 10-y-old ovariohysterectomized ring-tailed lemur (Lemur catta) was presented for exacerbation of respiratory signs. The lemur had a history of multiple examinations for various problems, including traumatic lacerations and recurrent perivulvar dermatitis. Examination revealed abnormal lung sounds and a femoral arteriovenous fistula with a palpable thrill and auscultable bruit in the right inguinal area. A diagnosis of congestive heart failure was made on the basis of exam findings, radiography, abdominal ultrasonography, and echocardiography. The lemur was maintained on furosemide until surgical ligation of the fistula was performed. Postoperative examination confirmed successful closure of the fistula and resolution of the signs of heart failure. Arteriovenous fistulas are abnormal connections between an artery and a vein that bypass the capillary bed. Large arteriovenous fistulas may result in decreased peripheral resistance and an increase in cardiac output with consequent cardiomegaly and high output heart failure. This lemur's high-flow arteriovenous fistula with secondary heart failure may have been iatrogenically induced during blood collection by prior femoral venipuncture. To our knowledge, this report is the first description of an arteriovenous fistula in a prosimian. Successful surgical correction of suspected iatrogenic femoral arteriovenous fistulas in a cynomolgus monkey (Macaca fascicularis) and a rhesus macaque (Macaca mulatta) have been reported previously. Arteriovenous fistula formation should be considered as a rare potential complication of venipuncture and as a treatable cause of congestive heart failure in lemurs.

Pharmacokinetics of a single intramuscular injection of ceftiofur crystalline-free acid in American black ducks (Anas rubripes).

OBJECTIVE: To determine the pharmacokinetic properties of 1 IM injection of ceftiofur crystalline-free acid (CCFA) in American black ducks (Anas rubripes). ANIMALS: 20 adult American black ducks (6 in a preliminary experiment and 14 in a primary experiment). PROCEDURES: Dose and route of administration of CCFA for the primary experiment were determined in a preliminary experiment. In the primary experiment, CCFA (10 mg/kg, IM) was administered to ducks. Ducks were allocated into 2 groups, and blood samples were obtained 0.25, 0.5, 1, 2, 4, 8, 12, 48, 96, 144, 192, and 240 hours or 0.25, 0.5, 1, 2, 4, 8, 24, 72, 120, 168, and 216 hours after administration of CCFA. Plasma concentrations of ceftiofur free acid equivalents (CFAEs) were determined by use of high-performance liquid chromatography. Data were evaluated by use of a naive pooled-data approach. RESULTS: The area under the plasma concentration versus time curve from 0 hours to infinity was 783 h•µg/mL, maximum plasma concentration observed was 13.1 µg/mL, time to maximum plasma concentration observed was 24 hours, terminal phase half-life was 32.0 hours, time that concentrations of CFAEs were higher than the minimum inhibitory concentration (1.0 µg/mL) for many pathogens of birds was 123 hours, and time that concentrations of CFAEs were higher than the target plasma concentration (4.0 µg/mL) was 73.3 hours. CONCLUSIONS AND CLINICAL RELEVANCE: On the basis of the time that CFAE concentrations were higher than the target plasma concentration, a dosing interval of 3 days can be recommended for future multidose CCFA studies.