Nelson R W, Ihle S L, Feldman E C, Bottoms G D
Department of Medicine, School of Veterinary Medicine, University of California, Davis 95616.
J Am Vet Med Assoc. 1991 Apr 15;198(8):1401-7.
Serum free thyroxine (fT4), thyroxine (T4), and 3,5,3'-triiodothyronine (T3) concentrations were determined in 62 healthy dogs, 51 dogs with hypothyroidism, and 59 euthyroid dogs with concurrent dermatopathy or concurrent illness for which hypothyroidism was a diagnostic consideration. Status of thyroid function was based on history, physical findings, results of thyrotropin response testing, requirement for thyroid hormone replacement therapy, and in 31 dogs, on results of histologic examination of a thyroid gland biopsy specimen. Serum fT4 concentration was determined, using a single-stage radioimmunoassay. Mean (+/- SD) serum fT4 concentration was significantly (P less than 0.05) greater in healthy dogs vs dogs with hypothyroidism (0.51 +/- 0.27 ng/dl vs 0.10 +/- 0.07 ng/dl). Significant difference in mean serum fT4 concentration was not evident between dogs with hypothyroidism and euthyroid dogs with hyperadrenocorticism (0.16 +/- 0.13 ng/dl) or peripheral neuropathy (0.19 +/- 0.10 ng/dl). Mean serum fT4 concentration in all other groups of euthyroid dogs with concurrent illness was similar to values in healthy dogs and was significantly (P less than 0.05) greater, compared with values in dogs with hypothyroidism. Similar results were found for mean serum T4 concentration. Comparison of serum fT4 vs T4 concentration revealed: sensitivity, 0.97 vs 0.98; specificity, 0.78 vs 0.73; predictive value for a positive test result, 0.79 vs 0.80; predictive value for a negative test result, 0.97 vs 0.97; and accuracy, 0.78 vs 0.86, respectively. Ten (17%) and 12 (20%) of 59 serum fT4 and T4 concentrations, respectively, were inappropriately low in euthyroid dogs with concurrent illness.(ABSTRACT TRUNCATED AT 250 WORDS)
测定了62只健康犬、51只甲状腺功能减退犬以及59只甲状腺功能正常但并发皮肤病或其他疾病（需考虑甲状腺功能减退诊断）犬的血清游离甲状腺素（fT4）、甲状腺素（T4）和3,5,3'-三碘甲状腺原氨酸（T3）浓度。甲状腺功能状态基于病史、体格检查结果、促甲状腺素反应试验结果、甲状腺激素替代治疗需求，对31只犬还基于甲状腺活检标本的组织学检查结果。采用单阶段放射免疫分析法测定血清fT4浓度。健康犬的平均（±标准差）血清fT4浓度显著高于甲状腺功能减退犬（P<0.05）（0.51±0.27 ng/dl对0.10±0.07 ng/dl）。甲状腺功能减退犬与患有肾上腺皮质功能亢进（0.16±0.13 ng/dl）或周围神经病变（0.19±0.10 ng/dl）的甲状腺功能正常犬之间，平均血清fT4浓度无显著差异。所有其他并发疾病的甲状腺功能正常犬组的平均血清fT4浓度与健康犬相似，且显著高于甲状腺功能减退犬（P<0.05）。血清T4平均浓度也得到类似结果。血清fT4与T4浓度比较显示：敏感性分别为0.97对0.98；特异性分别为0.78对0.73；阳性检测结果预测值分别为0.79对0.80；阴性检测结果预测值分别为0.97对0.97；准确性分别为0.78对0.86。59只并发疾病的甲状腺功能正常犬中，分别有10只（17%）和12只（20%）的血清fT4和T4浓度异常低。（摘要截断于250字）
