Lenfest Margret, Loftus John P, Huson Heather J, Gudkov Andrei, Andrianova Katerina, Fleyshman Daria, Wakshlag Joseph
Department of Clinical Sciences, Cornell University College of Veterinary Medicine, Ithaca, NY, United States.
Department of Animal Sciences, Cornell University College of Agriculture and Life Sciences, Ithaca, NY, United States.
Front Vet Sci. 2022 Jun 14;9:859066. doi: 10.3389/fvets.2022.859066. eCollection 2022.
Sled dogs are purpose-bred dogs selected for endurance work. Prior studies in racing dogs showed that serum thyroid parameters (total T4, free T4, and T3) are lower than the reference range in approximately 25% of dogs. Whether this is related to training, breeding, or body condition remains unclear. We hypothesized that retired sled dogs of normal body condition (9-13 years old) would have predominantly normal serum thyroid parameters and that serum thyroid status would be correlated to energy consumption based on metabolic body weight. Eighty-six sled dogs who were deemed healthy on physical exam, not on confounding medications, and without a prior diagnosis of hypothyroidism were included. All dogs' mean body condition scores were 5.1 ± 0.4 and body weight 24.5 ± 4.2 kg at fasting blood collection with stable dietary intake for 3 months before sampling. The total T4, free T4, and T3 serum concentrations were 23.4 ± 9.1 nmol/L, 9.53 ± 4.3 pmol/L, and 0.93 ± 0.39 nmol/L, respectively, with 38% lower than the reference range for total T4, 45% for free T4, and 37% for T3. All dogs were negative for thyroglobulin antibody, and TSH results were within normal ranges. Pearson's correlates based on kilocalories consumed on a metabolic body weight basis for total T4 ( = 0.14), free T4 ( = 0.01) and T3 ( = 0.23) showed poor correlation. No differences were observed between thyroid hormones and age, breed, or sex. Inactive, retired sled dogs can be misdiagnosed with hypothyroidism; therefore, our data suggests that misdiagnosis of hypothyroidism can occur and that the racing Alaskan sled dog has a unique reference range that should be considered when assessing serum thyroid status.
雪橇犬是为耐力工作而专门培育的犬种。先前对赛犬的研究表明，约25%的犬血清甲状腺参数（总T4、游离T4和T3）低于参考范围。这是否与训练、育种或身体状况有关尚不清楚。我们假设，身体状况正常（9至13岁）的退役雪橇犬血清甲状腺参数主要正常，且血清甲状腺状态与基于代谢体重的能量消耗相关。纳入了86只经体格检查被认为健康、未服用混杂药物且既往无甲状腺功能减退诊断的雪橇犬。在禁食采血时，所有犬的平均身体状况评分为5.1±0.4，体重为24.5±4.2 kg，采血前3个月饮食摄入稳定。总T4、游离T4和T3血清浓度分别为23.4±9.1 nmol/L、9.53±4.3 pmol/L和0.93±0.39 nmol/L，总T4低于参考范围38%，游离T4低于45%，T3低于37%。所有犬甲状腺球蛋白抗体均为阴性，促甲状腺激素结果在正常范围内。基于代谢体重消耗的千卡数，总T4（r = 0.14）、游离T4（r = 0.01）和T3（r = 0.23）的Pearson相关性显示相关性较差。甲状腺激素与年龄、品种或性别之间未观察到差异。不活动的退役雪橇犬可能被误诊为甲状腺功能减退；因此，我们的数据表明可能会发生甲状腺功能减退的误诊，并且在评估血清甲状腺状态时应考虑到阿拉斯加雪橇赛犬有独特的参考范围。
