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  • Author or Editor: Karin Muth Beale x
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Summary

Thyroid function was evaluated in 20 healthy dogs by thyrotropin (tsh) response testing. Two dose regimens were used: 5 IU of tsh given iv and 1 IU of tsh given iv. Blood samples were collected prior to and at 4 and 6 hours after tsh administration. Serum was obtained and analyzed for total 3,5,3′-tri-iodothyronine and thyroxine (T4) concentrations by radioimmunoassay. All dogs were classified as euthyroid on the basis of response to 5 IU of tsh at 4 and 6 hours. The 1-IU dose of tsh failed to induce adequate increase in T4 concentration in 7 dogs at 4 and 6 hours when the criteria for normal response were post-tsh serum concentration T4 ≥ 3.0 μg/dl and serum T4 increase by ≥ 100% over baseline serum T4 concentration. One IU of tsh induced increase in serum T4 concentration over baseline; however, the increase was significantly (P < 0.05) less than that in response to a 5-IU dose at 6 hours after administration of tsh.

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in Journal of the American Veterinary Medical Association

Summary

Fifty-eight dogs with generalized dermatologic disease that had not been given glucocorticoids systemically or topically within 6 weeks of entering the study were evaluated for thyroid function by use of the thyrotropin-response test. Dogs were classified as euthyroid or hypothyroid on the basis of test results and response to thyroid hormone replacement therapy. Baseline serum thyroxine (T4), free T4 (fT4), and triiodothyronine (T3) concentrations were evaluated in the 58 dogs. Serum T4, fT4, and T3 concentrations were evaluated in 200 healthy dogs to establish normal values. Hormone concentrations were considered low if they were less than the mean – 2 SD of the values for control dogs.

Specificity of T4 and fT4 concentrations was 100% in predicting hypothyroidism; none of the euthyroid dogs with generalized skin disease had baseline serum T4 or fT4 concentration in the low range. Sensitivity was better for fT4 (89%) than for T4 (44%) concentration. Significant difference was not observed in serum T4 and fT4 concentrations between euthyroid dogs with generalized skin disease and healthy control dogs without skin disease. Serum T3 concentration was not accurate in predicting thyroid function; most of the euthyroid and hypothyroid dogs with skin disease had serum T3 concentration within the normal range.

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in Journal of the American Veterinary Medical Association
in Journal of the American Veterinary Medical Association

Summary

Antithyroglobulin antibody (ata) values were higher in dogs with low total serum thyroxine (T4) and triiodothyronine (T3) values than in dogs with T3 and T4 values within reference value limits. In the population studied, Doberman Pinschers were predisposed to the development of ata; there was no sex predilection for development of ata. Antithyroglobulin antibodies and thyroid status were evaluated in 2 groups of healthy dogs (n = 30) and in 470 canine serum samples submitted for T3 and T4 value determination. Antithyroglobulin antibodies were evaluated by elisa, and thyroid status was evaluated by measurement of total serum T3 and T4 by radioimmunoassay.

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in Journal of the American Veterinary Medical Association

Summary

Effects of 4 commonly used sedatives on the wheal-and-flare response to histamine and flea antigen were evaluated in 8 flea-allergic Beagles. Skin testing was performed on 12 separate occasions, 3 to 4 days apart. Twelve intradermal injections were given during each skin test: 5 doubling dilutions of histamine phosphate, 6 doubling dilutions of flea antigen, and a phosphate-buffered saline solution (negative control). Of the 12 intradermal skin tests, 8 were control tests performed on nonsedated dogs. The remaining 4 tests were performed on dogs sedated with xylazine, ketamine and valium combination, acepromazine, or oxymorphone. Oxymorphone had the most profound effect on skin test results, significantly (P < 0.05) decreasing skin responsiveness in 8 of 11 test sites (by objective evaluation) and in 5 of 11 test sites (by subjective evaluation). Xylazine sedation enhanced skin test results in 4 of 11 test sites (by objective evaluation) and in 1 of 11 test sites (by subjective evaluation). In no instance did xylazine significantly decrease skin responsiveness to histamine or flea antigen. Xylazine is the recommended sedative in dogs when sedation is necessary for intradermal skin testing.

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in Journal of the American Veterinary Medical Association

Summary

Five cats were treated with an azathioprine suspension (2.2 mg/kg of body weight on alternate days) and 2 cats were given vehicle (controls) for 9 weeks. Complete blood and platelet counts and serum biochemistry variables were monitored weekly. Bone marrow aspirates were evaluated every 3 weeks, and core bone marrow biopsy was performed at the end of the study. Profound neutropenia (< 600 cells/μl) was observed in all treated cats, and 1 cat developed pancytopenia. Treatment was discontinued if the wbc count was < 3,000 cells/μl. Four weeks after discontinuation of azathioprine, 1 treated cat again was given azathioprine at a lower dosage (1.1 mg of azathioprine/kg on alternate days) and neutropenia recurred within 2 weeks. During treatment, 3 cats developed thrombocytosis, and 2 developed thrombocytopenia. In 4 of 5 cats, neutropenia and thrombocytopenia resolved when azathioprine was discontinued. Bone marrow cytologic examination during treatment revealed reduction of the neutrophil line, with relative increase in monocytes. Core bone marrow biopsy at the completion of the study revealed hypocellular marrow with marked decrease in the myeloid series in cats given azathioprine. One of the cats that was treated with azathioprine had a hypercellular marrow with increased numbers of mature granulocytes and precursors; however, azathioprine had been discontinued 3 weeks prior to biopsy. Alterations in serum biochemical variables were not associated with azathioprine. Two cats that were treated with azathioprine developed respiratory tract infections, and 1 of them was euthanatized during the study.

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in American Journal of Veterinary Research