FDA Alerts Pet Food Manufacturers About Thyroid Hormones in Pet Food
The U.S. Food and Drug Administration is advising pet owners and caretakers, veterinarians, and the pet food industry to be aware that pet food and treats made with livestock gullets—meat from the throat region—have the potential to contain thyroid tissue and thyroid hormones. Pets that eat food or treats containing thyroid hormones may develop hyperthyroidism, a disease that is rare in dogs and usually triggered by thyroid cancer.
Symptoms of hyperthyroidism include excessive thirst and urination, weight loss, increased appetite, restlessness, hyperactivity, elevated heart rate, rapid and/or labored breathing, vomiting and diarrhea. Continued exposure to excess thyroid hormones can cause damage to the heart and in some cases, death.
The FDA issued the alert after a recent Center for Veterinary Medicine investigation into reports of three dogs in different households that showed signs of hyperthyroidism. In these cases, extensive testing on all three dogs conducted at a reference laboratory showed elevated thyroid hormone in the blood, but ruled out thyroid cancer. Reference lab interviews with the dogs’ owners revealed that all three dogs had been fed BLUE Wilderness Rocky Mountain Recipe Red Meat Dinner Wet Food for Adult Dogs and/or Wellness 95% Beef Topper for Dogs.
Based on the recommendation of the reference lab’s consulting veterinarians, the feeding of these dog foods was discontinued. Once the dogs stopped eating these products for a few weeks, their clinical signs disappeared and thyroid hormone levels returned to normal. An FDA lab tested unopened cans of the two products and confirmed that they contained active thyroid hormone. The source of thyroid hormones is likely the use of gullets from which the thyroid glands were not completely removed before adding to pet food or treats.
After consulting with the FDA, both WellPet (the maker of Wellness) and Blue Buffalo (the maker of Blue Wilderness) initiated voluntary recalls of select lots of the affected products on March 17.
WellPet voluntarily recalled of certain lots of 13.2 ounce cans of Wellness 95% Beef Topper for Dogs with best-by dates of 02 FEB 19, 29 AUG 19, and 30 AUG 19 printed on the bottom of the can. The UPC Code is 076344894506.
Blue Buffalo Company voluntarily recalled of one lot of 12.5-ounce cans BLUE Wilderness® Rocky Mountain Recipe Red Meat Dinner Wet Food for Adult Dogs with a best-by date of June 7, 2019 printed on the bottom of the can. The UPC code is 840243101153.
In a letter addressed to members of the pet food industry, the FDA expressed appreciation for the cooperation and swift action taken by both companies to address this issue.
Pet food and treats in all forms (dry food, canned food, treats, etc.) with elevated thyroid hormone levels likely contains animal gullets (laryngeal tissue) in which the thyroid glands were not completely removed, said USAD officials. USDA prohibits the use of thyroid glands and laryngeal muscle tissue for human food. Any products containing livestock gullet or laryngeal tissue is a potential source of thyroid hormones.
If a thyroid gland is not completely removed from a gullet and that gullet is then added to pet food or treats, remnant thyroid tissue could be a source of thyroid hormones. One way to be certain that there are no traces of thyroid in pet food is to avoid the use of livestock gullets, USDA officials advised in the letter.
The USDA noted in the letter that the thyroid glands might not have been completely removed from animal gullets and then those gullets are used in pet food or treats. Suppliers can ensure that they have fully removed thyroid glands from gullets before providing them to manufacturers. The FDA recommends consulting industry trade organizations, such as the Pet Food Institute or the Association of American Feed Control Officials (AAFCO) for best practices and advice.
Manufacturers can carefully assess their suppliers’ practices and take steps to ensure that they are receiving raw materials and ingredients that do not contain thyroid hormone secreting tissue.
"If you suspect that there is a problem with your product or supply, the best course of action is to assess your products and practices, consulting the FDA as needed," the letter concluded.