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Objective

To determine outcome of cats with nonlymphoid tumors of the vertebral canal that undergo surgery.

Design

Retrospective study.

Animals

11 cats.

Procedure

Information obtained from the medical records included signalment, tumor location, gross evaluation of completeness of surgical excision, histologic diagnosis, and survival time.

Results

Median age of cats was 12 years; all cats had negative FeLV and feline immunodeficiency virus test results. All cats underwent a hemilaminectomy or dorsal laminectomy. The tumor was located in the thoracic portion of the vertebral column in 6 cats. Six cats had intradural-extramedullary tumors. Tumors included meningioma (n = 5), malignant nerve sheath tumors (2), and meningeal sarcoma, chondrosarcoma, lipoma, and osteosarcoma (1 each). One cat was lost to follow-up, 1 cat with meningioma was alive 1,400 days after surgery, and 1 cat with a nerve sheath tumor was alive 2,190 days after surgery. Median survival time for the other 4 cats with meningioma was 180 days (range, 30 to 600 days).

Clinical Implications

Cats with nonlymphoid vertebral canal tumors that undergo surgery may have a good prognosis. (J Am Vet Med Assoc 1997;210:663–664

Free access
in Journal of the American Veterinary Medical Association

Abstract

Objective—To characterize the biological effects of IM administration of a recombinant adeno-associated virus serotype 2 (rAAV2) vector containing feline erythropoietin (fEPO) cDNA and determine whether readministration of the vector or removal of muscle tissue at the injection sites alters those effects.

Animals—10 healthy 7-week-old specific pathogenfree cats.

Procedure—Cats received 1 × 107 infective units (iU; n = 3), 1 × 108 iU (3), or 1 × 109 iU (2) of rAAV2-fEPO vector IM (day 0). Two control cats received an rAAV2 vector containing the LacZ gene (1 × 109 iU, IM). In all cats, hematologic variables and serum fEPO concentration were measured at intervals; anti-rAAV2 antibody titer was measured on day 227. In cats that did not respond to treatment, the rAAV2- fEPO vector was readministered. Injection sites were subsequently surgically removed.

Results—Compared with control cats, cats treated with 1 × 109 iU of rAAV2-fEPO vector had increased Hct and serum fEPO concentrations. One of these cats developed pure RBC aplasia; its Hct normalized following injection site excision. Cats receiving lower doses of vector had no response; on retreatment, 1 of those cats developed sustained erythrocytosis that persisted despite injection site removal and the others did not respond or responded transiently. Antibodies against rAAV2 were detected in all vector-treated cats.

Conclusions and Clinical Relevance—Gene therapy may be an effective treatment for cats with hypoproliferative anemia. However, rAAV2-fEPO vector administration may result in pure RBC aplasia or pathologic erythrocytosis, and injection site removal does not consistently abolish the biological response. (Am J Vet Res 2005;66:450–456)

Full access
in American Journal of Veterinary Research

Abstract

Objective

To evaluate the potential synergy between bovine respiratory syncytial virus (BRSV) and 3-methylindole (3MI) in inducing respiratory disease in cattle.

Animals

20 mixed-breed beef calves.

Procedure

A 2 × 2 factorial design was used, with random assignment to the following 4 treatment groups: unchallenged control, BRSV challenge exposure (5 × 104 TCID50 by aerosolization and 5.5 × 105 TCID50 by intratracheal inoculation), 3MI challenge exposure (0.1 g/kg of body weight, PO), and combined BRSV-3MI challenge exposure. Clinical examinations were performed daily. Serum 3MI concentrations, WBC counts, PCV, total plasma protein, and fibrinogen concentrations were determined throughout the experiment. Surviving cattle were euthanatized 7 days after challenge exposure. Pulmonary lesions were evaluated at postmortem examination.

Results

Clinical respiratory disease was more acute and severe in cattle in the BRSV-3MI challenge-exposure group than in cattle in the other groups. All 5 cattle in this group and 3 of 5 cattle treated with 3MI alone died or were euthanatized prior to termination of the experiment. Mean lung displacement volume was greatest in the BRSV-3MI challenge-exposure group. Gross and histologic examination revealed that pulmonary lesions were also most severe for cattle in this group.

Conclusions and Clinical Relevance

Feedlot cattle are commonly infected with BRSV, and 3MI is produced by microflora in the rumen of all cattle. Our results suggest that there is a synergy between BRSV and 3MI. Thus, controlling combined exposure may be important in preventing respiratory disease in feedlot cattle. (Am J Vet Res 1999;60:563–570)

Free access
in American Journal of Veterinary Research