The Pulse Of Veterinary Medicine
Vet-To-Vet Conversation With IDEXX
After four dogs presented with clinical signs of hyperthyroidism, two dog food companies have recalled specific lots of canned dog food due to elevated levels of beef thyroid hormone.
Although we tend to consider hyperthyroidism only in cats, it is a differential worth considering in a dog presenting with consistent clinical signs. The clinical signs seen in dogs with high thyroid levels are very similar to those seen in cats and may include vomiting, diarrhea, increased heart rate, panting, restlessness, increased appetite with weight loss and increased thirst and urination.
Hyperthyroidism due to endogenous thyroid hormone in dogs is rare. When it occurs, it is almost always due to a thyroid tumor, with the vast majority being thyroid carcinoma. Exogenous thyroid hormone can also cause signs of hyperthyroidism in dogs. Iatrogenic hyperthyroidism is more commonly seen in dogs on excess thyroid supplementation. As recent recalls demonstrate, however, exposure to excess thyroid hormone can also occur via pet foods. Pet foods may contain high levels of thyroid hormone when the neck muscles and associated thyroid glands are included in the processing. A total T4 test, performed either at the reference laboratory or with the Catalyst Total T4 Test, should be considered as part of your diagnostic work-up of dogs presenting signs that could be attributable to hyperthyroidism.
Issues with manufacturing may occur even with highly reputable pet food companies. To check if a particular pet food lot is part of a recall, check the FDA pet food recall site: www.fda.gov/animalveterinary/safetyhealth/recallswithdrawals