Wheaton Catharine J, Sullivan Kathleen E, Bassiouny Enass, Burns Charlene M, Smukall Matthew J, Hendon Jill M, Mylniczenko Natalie D
Disney's Animals, Science and Environment, Animal Programs, Lake Buena Vista, FL, United States.
Michigan State University Veterinary Diagnostic Laboratory, College of Veterinary Medicine, East Lansing, MI, United States.
Front Vet Sci. 2025 Feb 26;12:1504527. doi: 10.3389/fvets.2025.1504527. eCollection 2025.
Thyroid disease is an important condition to understand in elasmobranchs, with goiters being predominant. To identify dysfunction, measuring serum thyroid hormone levels is a standard of practice for diagnosing disease in most species. Although these levels have been reported in elasmobranch literature, the testing methodology is varied and values are not clinically useful for most aquarium species. In a group of aquarium-housed elasmobranchs, thyroid hormone levels had been persistently low or not detectable in otherwise healthy animals as well as animals with thyroid disease. The concern for reliability of these results to diagnose thyroid disease, prompted a shift to serum iodine levels as a proxy to determine thyroid health.
This study assesses thyroid hormone and iodine levels as compared to thyroid disease stage in elasmobranchs with and without dietary supplementation, to determine the efficacy of using these serum values to guide clinical decisions.
Serum thyroid hormone results were lower than the readable range of the standard curve in both sharks and rays; thus reported values are usually extrapolated. Including additional standards down to the limit of sensitivity improved detection, however increasing the sample volume tested was determined to be the most important factor for obtaining measurable results in low-value thyroid hormone samples. Serum iodine levels are reported in three groups of southern stingrays (). Other elasmobranch species maintained in aquaria with and without thyroid disease were used for biological comparisons. Non-goiter, diseased animals reliably had elevated levels (over baseline) of thyroid hormones and iodine; in goiter cases, hormones were not useful. Additionally, it was found that cobalt levels were also elevated in some disease states and correlated positively with serum iodine levels.
Current available thyroid testing may not provide clinically useful values unless methodology is adjusted, or disease is severe. Serum iodine may be a useful marker to investigate thyroid health. Further, while thyroid disease may be identifiable with thyroid hormones, it is not straightforward or substantial enough alone for diagnosis.
甲状腺疾病是了解板鳃亚纲动物时的一个重要情况，甲状腺肿最为常见。为了确定功能障碍，测量血清甲状腺激素水平是大多数物种诊断疾病的标准做法。尽管这些水平已在板鳃亚纲动物文献中有所报道，但检测方法各不相同，且这些值对大多数水族箱物种的临床诊断并无实际用途。在一组饲养在水族箱中的板鳃亚纲动物中，甲状腺激素水平在其他方面健康的动物以及患有甲状腺疾病的动物中一直较低或无法检测到。由于担心这些结果用于诊断甲状腺疾病的可靠性，促使人们转而使用血清碘水平作为判断甲状腺健康的替代指标。
本研究评估了有或没有膳食补充的板鳃亚纲动物的甲状腺激素和碘水平，并与甲状腺疾病阶段进行比较，以确定使用这些血清值指导临床决策的有效性。
鲨鱼和鳐鱼的血清甲状腺激素结果均低于标准曲线的可读范围；因此报告的值通常是外推得出的。增加直至灵敏度极限的额外标准可改善检测效果，然而，增加检测的样本量被确定为在低甲状腺激素值样本中获得可测量结果的最重要因素。报告了三组南方黄貂鱼的血清碘水平。还使用了饲养在水族箱中有或没有甲状腺疾病的其他板鳃亚纲物种进行生物学比较。无甲状腺肿的患病动物的甲状腺激素和碘水平可靠地升高（超过基线）；在甲状腺肿病例中，激素并无诊断价值。此外，还发现钴水平在某些疾病状态下也会升高，且与血清碘水平呈正相关。
除非调整方法或疾病严重，否则目前可用的甲状腺检测可能无法提供临床有用的值。血清碘可能是研究甲状腺健康的有用标志物。此外，虽然甲状腺疾病可能通过甲状腺激素来识别，但仅凭甲状腺激素进行诊断并不直接或充分。
