Thyroid hormones in food sicken dogs

At least three dogs developed hyperthyroidism after eating food containing active thyroid hormones, prompting two recalls March 17.

In a March 27 letter to veterinarians, Food and Drug Administration officials said the dogs, which live in separate homes, had unusual clinical signs including increased thirst, increased urination, restlessness, and weight loss. Thyroid panel results were most consistent with an external hormone source, and the dogs’ clinical signs improved over three to four weeks with a change in diet.

Product tests revealed thyroid hormone and excess iodine were present in unopened cans from the same product lines fed to the dogs, likely because the foods contained thyroid gland tissue, agency information states.

The sickened dogs are a 4-year-old Shetland Sheepdog, an 8-year-old Tibetan Terrier, and a 15-year-old Labrador Retriever.

One recall affects one lot of Blue Buffalo Company’s Blue Wilderness Rocky Mountain Recipe Red Meat Dinner Wet Food for Adult Dogs; cans from that lot will have a UPC of 840243101153 and a best-sold-by date of June 7, 2019. The other recall affects WellPet’s Wellness 95% Beef Topper for Dogs in 13.2-ounce cans with best by dates of Feb. 2, 2019, Aug. 29, 2019, and Aug. 30, 2019.

The agency letter indicates the unique illnesses in these dogs “reinforce the importance of practitioners getting a detailed dietary history, including the type and amount of food as well as frequency of consumption.” Veterinarians who suspect a dog has such an external source of hyperthyroidism may want to run a full thyroid panel “including T3, free T3, T4, free T4, TSH, thyroid autoantibodies, and iodine,” the letter states.

FDA officials also asked that veterinarians report any laboratory results and clinical signs consistent with exogenous hyperthyroidism.

The letter to veterinarians is available at jav.ma/FDAthyroid.