Reproductive suppression of giraffe (Giraffa camelopardalis) under managed care using a GnRH immunological product.

Giraffe present unique contraception challenges as males persistently pursue females during estrus. Year-round pursuit during frequent recurring estrus can pose significant risk under slippery conditions. Complete ovarian suppression is a useful tool in giraffe because it eliminates estrous behavior, interest from the male, and controls reproduction. Effective reproduction control in giraffes has been achieved with porcine zona pellucida, oral melengestrol acetate, and depot medroxy-progesterone acetate. However, these methods allow some degree of folliculogenesis and estrous behavior. Improvest® is a gonadotropin releasing hormone (GnRH) immunological product that elicits antibodies against GnRH and abrogates the effects of endogenous GnRH. This study evaluated the efficacy of Improvest® for gonadal suppression in seven females and one male giraffe by monitoring steroid hormones. Seven female giraffe were treated intramuscularly with an initial dose, a booster at 4 weeks and maintenance boosters at 3-month intervals (600 µg/dose) for 12 months. Six females were on supplemental contraception during the induction phase because separation from males was not possible. In the male (treated with 400 µg), testosterone concentrations decreased after the second injection. However, even with low serum testosterone concentrations, mounting (of nontreated females) behavior was still observed occasionally. Ovarian activity was suppressed in all treated females and interest by the males stopped; supplemental contraceptives (during the induction phase) did not impede the effect of Improvest®. After 15.3 months (seven doses), Improvest® was discontinued in three females which no longer needed contraception. In these females, ovarian activity was noted approximately 90 days after the last dose.

Thyroid neoplasia in captive raccoons (Procyon lotor).

Two adult, spayed, female raccoons were diagnosed with thyroid neoplasia. One raccoon had a palpable, left-sided, nonfunctional thyroid adenocarcinoma which was treated with a thyroidectomy twice with local recurrence both times. After the second recurrence, pulmonary metastases were identified. A third thyroidectomy was performed, and a vascular access port was placed for administration of intravenous doxorubicin. The raccoon developed pancytopenia and became anorexic after chemotherapy, and the owner elected humane euthanasia. The second raccoon had nonpalpable, bilateral, functional follicular thyroid adenomatous hyperplasia and was treated with a right thyroidectomy and a partial left thyroidectomy, leaving behind the grossly normal portion of the left thyroid. However, the animal was still hyperthyroid after surgery and was then successfully managed with topical methimazole gel. Thyroid pathology has been documented in raccoons in Europe, but is not reported in the United States. Thyroid neoplasia in raccoons can occur as a nonfunctional adenocarcinoma, as is commonly reported in dogs, or as a functional adenoma, as is commonly reported in cats. Raccoons with adenocarcinomas should be evaluated for pulmonary metastasis. Methimazole gel may be a viable treatment option for raccoons with hyperthyroidism.

Intraocular sarcomas in two rabbits.

Intraocular neoplasms are described in 2 adult rabbits. The left globe of an 8-year-old male rabbit was enucleated after chronic inflammatory disease resulted in a nonvisual eye. The left globe of a 5-year-old female rabbit also was enucleated after a history of lens-induced uveitis, cataract formation, and resultant glaucoma. In both rabbits, histopathology revealed a variably pleomorphic, poorly differentiated, invasive, intraocular spindle cell neoplasm closely associated with lens and lens capsular fragments. Gram stains failed to detect bacterial organisms or Encephalitozoon cuniculi. Polymerase chain reaction assays, used to amplify the 16S RNA gene of numerous bacteria and E. cuniculi, were also negative. Immunohistochemical staining demonstrated strong, diffuse expression for vimentin; however, staining for smooth muscle actin, cytokeratin, S100, and desmin were negative. Long-standing intraocular inflammation and/or traumatic insults to the eyes were considered as causes of these neoplasms. The histologic features of these intraocular neoplasms closely resemble post-traumatic ocular sarcomas in cats.

Infection with Aleutian disease virus-like virus in a captive striped skunk.

CASE DESCRIPTION: A 5-month-old captive female striped skunk (Mephitis mephitis) was evaluated because of lethargy, signs of depression, azotemia, and erythema of the skin around the eyes. CLINICAL FINDINGS: Antemortem diagnostic tests revealed renal disease but failed to identify an etiologic agent. A diagnosis of severe nonsuppurative interstitial nephritis was made on the basis of results of histologic examination of renal biopsy specimens. TREATMENT AND OUTCOME: The skunk was administered isotonic fluids SC daily and later every other day because of the handling-related stress. Because of the skunk's deteriorating condition, it was euthanized after 24 days of supportive care. Aleutian disease was diagnosed on the basis of positive results of a PCR assay that targeted the DNA from Aleutian disease virus (ADV); positive results for ADV were also obtained by use of plasma counterimmunoelectrophoresis and an ELISA. Genetic sequencing of the 365-base pair PCR product revealed 90% sequence identity with mink ADV. CLINICAL RELEVANCE: In the skunk of this report, infection with a skunk-specific parvovirus resulted in clinical signs and pathologic changes similar to those associated with ADV infection in mink. For skunks with signs of renal failure, differential diagnoses should include parvovirus infection. In confirmed cases of infection with this ADV-like virus, appropriate quarantine and biosecurity measures should be in place to prevent spread to other susceptible animals within a zoological collection.