Consumer complaints about sick pets have spurred nationwide recalls by WellPet LLC and Blue Buffalo Co. because of potentially excessive levels of beef thyroid hormone in their dog foods.

Each company — WellPet LLC of Tewksbury, MA, and Blue Buffalo Co. of Wilton, CT — recalled specific production lots of one flavor of their canned dog food.

The recalled products are:

• WellPet’s “Wellness 95% Beef Topper for Dogs” in 13.2-ounce cans with best-by dates of “02 FEB 19,” “29 AUG 19” and “30 AUG 19.” The best-by dates can be found on the bottom of the cans.
• Blue Buffalo’s “Blue Wilderness Rocky Mountain Recipe Red Meat Dinner Wet Food for Adult Dogs” in 12.6-ounce cans with the UPC number 840243101153 and a best-by date of June 7, 2019, on the bottom of the cans.

The Food and Drug Administration is investigating four complaints, one associated with the Blue Buffalo product and three associated with the WellPet product. The investigation revealed the potential “…for elevated levels of naturally occurring beef thyroid hormone” in these products, according to the recall notices.

Thyroid hormone can be introduced into meat through the process of “gullet trimming,” which is the harvest of the neck muscle from the area of the larynx, according to the New England Journal of Medicine.

In 1984-1985, the U.S. Centers for Disease Control and Prevention investigated an outbreak of thyrotoxicosis that affected 121 residents of Minnesota, South Dakota and Iowa. The source of the outbreak proved to be beef trimmings from a plant near Luverne, MN. The meat plant employed gullet trimming to harvest meat from the area of the larynx, a process that resulted in portions of the thyroid being included in the harvested meat.

based on conclusions from the investigation, the U.S. Department of Agriculture prohibited gullet trimmings in beef and pork for human consumption. Gullets and meat trimmed from the area of the larynx are still permitted in pet food.

Dogs that ingest excessive beef thyroid hormone may exhibit symptoms that include increased thirst and urination, weight loss, increased heart rate and restlessness. Prolonged exposure to high thyroid hormone levels may lead to additional symptoms, such as vomiting, diarrhea, and rapid or difficulty breathing.

These symptoms are similar to those produced by an overactive thyroid.

The recalled Blue Buffalo dog food was distributed nationwide through pet specialty and online retailers. The WellPet dog food was distributed throughout North America online and through pet specialty stores. PetSmart and Pet Food Express have posted recall notices for both products on their websites.