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Abstract

Objective

To determine the phenotype of naturally developing lymphomas in young ferrets.

Animals

10 ferrets with lymphoma.

Procedure

Neoplastic tissues were graded histologically according to the National Cancer Institute's Working Formulation for non-Hodgkin’s lymphoma and phenotype was determined by means of immunohistochemical staining. A polyclonal anti-human CD3 and a monoclonal anti-human CD79 antibody were used to classify the lymphomas in situ as T-cell or B-cell origin. Specificity of antibodies was determined by evaluating lymphoid tissue from normal ferrets in situ, which was confirmed by western blot analyses.

Results

All 10 ferrets had clinically aggressive tumors, irrespective of the phenotype. Nine ferrets had T-cell lymphoma that extensively involved the mediastinum. Remnants of thymic tissue, indicative of thymic origin, were identified in lymphoma of these 9 ferrets. One ferret had a B-cell multicentric lymphoma without involvement of the mediastinum.

Conclusions

The majority of lymphomas in these young ferrets involved the mediastinum and were of T-cell phenotype.

Impact for Human Medicine

There are many similarities between the lymphoma syndrome of ferrets and the condition documented for cats and children with lymphoma of the mediastinal area.

Clinical Relevance

Differential diagnoses for young ferrets with clinical signs of lethargy or respiratory distress should include T-cell lymphoma of the mediastinum. ((Am J Vet Res 1998;59:1281-1286)

Free access
in American Journal of Veterinary Research

Abstract

Objective—To evaluate pituitary-adrenal function in a population of critically ill dogs by measuring serial plasma concentrations of basal cortisol, ACTH-stimulated cortisol, and endogenous ACTH.

Design—Prospective study.

Animals—20 critically ill dogs admitted to an intensive care unit (ICU).

Procedure—Basal plasma cortisol, ACTH-stimulated cortisol, and endogenous ACTH concentrations were measured for each dog within 24 hours of admission and daily until death, euthanasia, or discharge from the ICU. Established reference ranges for healthy dogs were used for comparison. Survival prediction index (SPI) scores were calculated for each dog within 24 hours of admission.

Results—No significant difference was found between initial concentrations of basal cortisol, ACTH-stimulated cortisol, and endogenous ACTH in 13 dogs that survived and those in 7 dogs that died. High initial basal endogenous ACTH concentrations were correlated with subsequent high values. Low basal ACTH-stimulated cortisol concentrations were predictive of higher subsequent values. All basal and ACTH-stimulated cortisol concentrations were within or above the reference range in the 52 plasma samples collected from the 20 dogs during hospitalization. The SPI scores correlated with outcome (ie, alive or dead), but none of the plasma hormone concentrations correlated with SPI score or outcome.

Conclusions and Clinical Relevance—Results indicate that none of the critically ill dogs in our study population developed adrenal insufficiency during hospitalization in the ICU. (J Am Vet Med Assoc 2002;220:615–619)

Full access
in Journal of the American Veterinary Medical Association

Abstract

Objective

To determine adverse effects of single and multiple doses of liposome-encapsulated cis-bis-neodecanoato-trans-R, R-1, 2-diaminocyclohexane platinum (II) (L-NDDP) administered IV to healthy adult cats.

Animals

10 healthy adult cats.

Procedure

8 cats were given a single dose of L-NDDP (at rates of 75, 100, 150, or 200 mg/m2), and 2 cats were given liposomal lipid (1,500 mg/m2). Six of the 10 cats were given doses of L-NDDP at the maximum tolerated dosage (100 mg/m2) or a lower dosage (75 mg of L-NDDP/m2) at 21-day intervals, for a total of 4 treatments. Hematologic and serum biochemical analyses, urinalyses, and physical examinations were used to monitor effects of L-NDDP.

Results

All cats had transient pyrexia, lethargy, vomiting (1 to 3 times/24 h), inappetence, and an acute species-specific infusion reaction that was prevented by administration of atropine-diphenhydramine. Dose-limiting toxicosis was evident as a 10- day course of lethargy, intermittent vomiting, and diarrhea. In cats given multiple doses, dose-related thrombocytopenia, cumulative myelosuppression, transient increased hepatic transaminase activity, and mild to moderate hepatic hydropic degeneration and proximal renal tubular lipidosis in excess of lipidosis expected for this species were detected. Bone marrow hypoplasia was detected in some cats that received higher doses (cumulative dosages of 300 or 400 mg of L-NDDP/m2).

Conclusion

Cats can safely be given L-NDDP at potentially therapeutic dosages without inducing renal or pulmonary toxicoses.

Clinical Relevance

Because L-NDDP has better tumoricidal activity than cisplatin (in vivo and in vitro) and is not cross resistant, it may be similarly or more efficacious than cisplatin in humans and dogs. (Am J Vet Res 1999;60:257–263)

Free access
in American Journal of Veterinary Research

Abstract

Objective—To determine whether thalidomide inhibits the growth of primary and pulmonary metastatic canine osteosarcoma in mice after xenotransplantation.

Animals—Athymic nude mice.

Procedure—Canine osteosarcoma cells were injected SC in 50 mice. Mice were randomly placed into the following groups: control group (n = 13; DMSO [drug vehicle] alone [0.1 mL/d, IP]); low-dose group (12; thalidomide [100 mg/kg, IP]), mid-dose group (13; thalidomide [200 mg/kg, IP]); and high-dose group (12; thalidomide [400 mg/kg, IP]). Starting on day 8, treatments were administered daily and tumor measurements were performed for 20 days. On day 28, mice were euthanatized and primary tumors were weighed. Lungs were examined histologically to determine the number of mice with metastasis and tumor emboli. Mean area of the pulmonary micrometastatic foci was determined for mice from each group.

Results—Primary tumor size and weight were not significantly different among groups. The number of mice in the mid-dose (200 mg/kg) and high-dose (400 mg/kg) groups with micrometastasis was significantly less than the number of control group mice; however, the number of mice with tumor emboli was not affected by thalidomide treatment. Size of micrometastasis lesions was not affected by thalidomide treatment.

Conclusions and Clinical Relevance—Mean area of micrometastases was not affected by treatment; however, growth of micrometastases had not yet reached an angiogenesis-dependent size. Although thalidomide did not affect growth of primary tumors in mice after xenotransplantation of canine osteosarcoma cells, our findings indicate that thalidomide may interfere with the ability of embolic tumor cells to complete the metastatic process within the lungs. ( Am J Vet Res 2004;65:659–664)

Full access
in American Journal of Veterinary Research

Abstract

Objective—To determine response rates and survival times for cats with lymphoma treated with the University of Wisconsin-Madison chemotherapy protocol.

Design—Retrospective study.

Animals—38 cats with lymphoma.

Procedure—Medical records were reviewed, and information on age, sex, breed, FeLV and FIV infection status, anatomic form, clinical stage, and survival time was obtained. Immunophenotyping was not performed.

Results—Mean ± SD age of the cats was 10.9 ± 4.4 years. Overall median survival time was 210 days (interquartile range, 90 to 657 days), and overall duration of first remission was 156 days (interquartile range, 87 to 316 days). Age, sex, anatomic form, and clinical stage were not significantly associated with duration of first remission or survival time. Eighteen of the 38 (47%) cats had complete remission, 14 (37%) had partial remission, and 6 (16%) had no response. Duration of first remission was significantly longer for cats with complete remission (654 days) than for cats with partial remission (114 days). Median survival time for cats with complete remission (654 days) was significantly longer than median survival time for cats with partial remission (122 days) and for cats with no response (11 days).

Conclusions and Clinical Relevance—Results suggested that a high percentage of cats with lymphoma will respond to treatment with the University of Wisconsin-Madison chemotherapy protocol. Age, sex, anatomic form, and clinical stage were not significantly associated with duration of first response or survival time, but initial response to treatment was. (J Am Vet Med Assoc 2005;227:1118–1122)

Full access
in Journal of the American Veterinary Medical Association

Abstract

Objective

To determine whether healthy dogs given high doses of methylprednisolone sodium succinate (MPSS) develop gastrointestinal tract ulcers and hemorrhage.

Animals

19 healthy male hound-type dogs.

Procedure

Dogs were assigned randomly to intravenously receive high doses of MPSS (30 mg/kg of body weight, initially, then 15 mg/kg 2 and 6 hours later, and, subsequently, every 6 hours for a total of 48 hours; n = 10) or an equal volume of saline (0.9% NaCl) solution (9). Gastroduodenoscopy was performed before and after treatment. Endoscopic evidence of gross hemorrhage in the cardia, fundus, antrum, and duodenum of each dog was graded from none (0) to severe (3), and a total stomach score was calculated as the sum of the regional gastric scores. Number of ulcers were recorded. The pH of gastric fluid and evidence of occult gastric and fecal blood were measured. Food retention was recorded.

Results

Gastric hemorrhage was evident in all dogs after MPSS administration and was severe in 9 of 10 dogs but not visible in any dog after saline treatment. Occult gastric blood was detected more commonly (9/10 vs 2/9), median gastric acidity was greater (pH 1 vs pH 3), and food was retained more commonly (7/10 vs 1/9) in the stomach of MPSS-treated dogs.

Conclusions and Clinical Relevance

High doses of MPSS cause gastric hemorrhage in dogs. All dogs treated with high doses of MPSS should be treated with mucosal protectants or antacids to prevent gastric hemorrhage. (Am J Vet Res 1999;60:977–981)

Free access
in American Journal of Veterinary Research

Abstract

Objective

To determine whether administration of misoprostol prevents gastric hemorrhage in healthy dogs treated with high doses of methylprednisolone sodium succinate (MPSS).

Animals

18 healthy hound-type dogs of both sexes.

Procedure

All dogs were given high doses of MPSS (30 mg/kg of body weight, initially, then 15 mg/kg 2 and 6 hours later, and, subsequently, q 6 h for a total of 48 hours) IV. Dogs were assigned randomly to receive concurrent treatment with misoprostol (4 to 6 μg/kg, PO, q 8 h; n = 9) or an empty gelatin capsule (9). Gastroduodenoscopy was performed before and after treatment. Hemorrhage was graded from none (0) to severe (3) for each cardia, fundus, antrum, and duodenum. A total stomach score was calculated as the sum of the regional stomach scores. Food retention was recorded, and pH of gastric fluid was determined. Gastric and fecal occult blood was measured.

Results

Gastric hemorrhage was evident in all dogs after MPSS administration, and its severity was similar in both groups. Median total stomach score was 6 for misoprostol-treated dogs and 5.5 for dogs given the gelatin capsule. Difference in gastric acidity, frequency of food retention, and incidence of occult blood in gastric fluid and feces was not apparent between the 2 groups.

Conclusions and Clinical Relevance

Administration of misoprostol (4 to 6 μg/kg, PO, q 8 h) does not prevent gastric hemorrhage caused by high doses of MPSS. Alternative prophylactic treatment should be considered. (Am J Vet Res 1999;60:982–985)

Free access
in American Journal of Veterinary Research

Abstract

Objective—To determine the effects of administration of 1 dose of tulathromycin on the incidence of various diseases and growth, identify risk factors for slow growth, and determine the association of Mycoplasma bovis status with the incidence of otitis media in calves.

Design—Randomized controlled trial and cross-sectional study.

Animals—788 dairy heifer calves (median age, 3 days).

Procedures—Calves received tulathromycin or a saline (0.9% NaCl) solution control treatment once. Calves were observed daily for 8 weeks by farm staff to detect diseases. Nasal swab specimens were collected from some calves for Mycoplasma spp culture.

Results—Tulathromycin-treated calves had significantly lower odds of developing otitis media (OR, 0.41; 95% confidence interval, 0.58 to 0.82) versus control calves. Control calves had significantly higher odds of developing diarrhea (OR, 1.8; 95% confidence interval, 1.2 to 2.6) versus tulathromycin-treated calves. Control calves and those with failure of passive transfer, fever, lameness, respiratory tract disease, or diarrhea had significantly lower average daily gain versus other calves. Seventeen of the 66 (26%) calves that underwent repeated testing had positive Mycoplasma spp culture results, but positive results were not associated with otitis media. One of 42 calves with otitis media tested for Mycoplasma spp had positive results, and 1 of 43 age-matched calves without otitis media had positive results.

Conclusions and Clinical Relevance—Tulathromycin-treated calves in this study had a lower incidence of diarrhea and otitis media versus control calves. Various diseases had negative effects on average daily gain. Mycoplasma bovis status was not associated with otitis media in calves.

Full access
in Journal of the American Veterinary Medical Association

Abstract

Objective—To determine clinical response and toxic effects of cis-bis-neodecanoato-trans-R,R-1,2- diaminocyclohexane platinum (II) (L-NDDP) administered IV at escalating doses to cats with oral squamous cell carcinoma (SCC).

Animals—18 cats with oral SCC.

Procedure—Cats that failed to respond to conventional treatment or had nonresectable tumors were included. Data included a CBC, serum biochemical analyses, urinalysis, cytologic examination of a fineneedle aspirate of enlarged lymph nodes, and thoracic and oral radiographs for clinical staging. A starting dose (75 to 100 mg/m2 of L-NDDP) was administered IV. At 21-day intervals, subsequent doses increased by the rate of 5 or 10 mg/m2. Response was evaluated every 21 days by tumor measurement and thoracic radiography. Quality of life was assessed by owners, using a performance status questionnaire.

Results—On average, cats received 2 treatments. Toxicoses included an intermittent, acute anaphylactoid- parasympathomimetic reaction, lethargy or sedation (≤ 24 hours), inappetence or signs of depression (≤ 72 hours), mild to moderate increase in hepatic enzyme activity, and melena. Pulmonary, renal, or hematopoietic abnormalities were not evident. Performance status surveys indicated normal behavior and grooming or decreased activity and self-care (19/20 assessments), ate well with or without assistance (15/20), and did not lose weight (15/20). Median survival time was 59.8 days (mean, 54.1 days).

Conclusions and Clinical Relevance—L-NDDP was ineffective for treatment of cats with oral SCC. None of the cats had a complete or partial remission. Acute toxicoses and poor therapeutic response limit therapeutic usefulness of L-NDDP in cats, unless dosage, frequency, and administration procedures can be improved. (Am J Vet Res 2000;61: 791–795)

Full access
in American Journal of Veterinary Research