Office of Surveillance and Compliance, Food and Drug Administration Center for Veterinary Medicine, Rockville, MD, USA.
Office of Research, Food and Drug Administration Center for Veterinary Medicine, Laurel, MD, USA.
Top Companion Anim Med. 2021 Jun;43:100521. doi: 10.1016/j.tcam.2021.100521. Epub 2021 Feb 5.
Dietary exogenous thyrotoxicosis is infrequently observed in pet food. A retrospective evaluation of pet food investigations (PFI) was conducted for 17 dogs, including review of medical records, dietary and environmental exposure interviews, food testing, and regulatory action. Five PFIs occurring between 2016 and 2018 involved 7 food products including 2 food types, jerky treats or canned food, made from beef or bison. The dogs' serum thyroid hormone concentrations were evaluated before and after diet change. The foods were tested for active thyroid hormones and hormone precursors using high performance liquid chromatography with inductively coupled plasma mass spectrometry detection. The foods were also examined microscopically. Serum thyroid hormone concentrations of thyroxine (T4) varied depending on the food type consumed. Dogs that consumed dried jerky containing greater T4 concentrations often had increased serum T4 concentrations, whereas dogs that consumed canned products containing greater and 3,4,5- and 3,5,3'-triiodothyronine (T3) concentrations often had decreased serum T4 concentrations. After the diets were changed, serum T4 and T3 concentrations normalized at 1 month. Seven foods containing beef or bison had iodine concentrations greater than 11 mg/kg, and iodine speciation identified variable concentrations of iodide, T4, T3, monoiodotyrosine (MIT), and di-iodotyrosine (DIT). Thyroid gland was found in microscopic sections from one finished food and one ingredient, gullet. FDA performed Health Hazard Evaluations to categorize the exposure risk, and 5 foods were recalled for which the product packaging had not been discarded. Dietary exogenous thyrotoxicosis should be considered in dogs exhibiting clinical signs compatible with hyperthyroidism, especially if consuming beef-based food. A thyroid panel that includes serum iodine, coupled with a thorough feeding history can aid in diagnosis. Thyrotoxicosis is typically reversible after removing the contaminated food from the diet.
宠物食品中罕见出现外源性甲状腺毒症。对 17 只犬进行了宠物食品调查（PFI）回顾性评估，包括查阅病历、饮食和环境暴露访谈、食品检测和监管行动。2016 年至 2018 年间发生的 5 起 PFI 涉及 7 种食品，包括 2 种食品类型，即牛肉或野牛制成的肉干零食或罐头食品。在改变饮食前后评估了犬的血清甲状腺激素浓度。使用高效液相色谱法-电感耦合等离子体质谱检测法检测食品中的活性甲状腺激素和激素前体。还对食品进行了显微镜检查。血清甲状腺素（T4）的浓度因食用的食物类型而异。食用含有较高 T4 浓度的干肉干的犬常伴有血清 T4 浓度升高，而食用含有较高 T3 和 3,4,5-和 3,5,3'-三碘甲状腺原氨酸（T3）浓度的罐头产品的犬常伴有血清 T4 浓度降低。改变饮食后，1 个月内血清 T4 和 T3 浓度恢复正常。7 种含牛肉或野牛的食品碘含量大于 11mg/kg，碘形态分析鉴定出碘化物、T4、T3、单碘酪氨酸（MIT）和二碘酪氨酸（DIT）的浓度不同。在一个成品食品和一个原料（食管）的显微镜切片中发现了甲状腺组织。FDA 进行了健康危害评估以对暴露风险进行分类，有 5 种食品被召回，因为产品包装未被丢弃。如果犬出现与甲状腺功能亢进症相符的临床症状，特别是如果食用基于牛肉的食物，应考虑其患有外源性甲状腺毒症。包括血清碘在内的甲状腺功能检测，加上全面的喂养史有助于诊断。去除饮食中的污染食物后，甲状腺毒症通常是可逆的。
