Presumed Choline Chloride Toxicosis in Cats With Positive Ethylene Glycol Tests After Consuming a Recalled Cat Food.

Four previously healthy adult domestic shorthair cats (2 male, 2 female) from one household developed acute vomiting and ataxia less than 12 hours after consuming a commercial canned cat food. Blood work abnormalities included mild hyperglycemia with increased alanine aminotransferase (n = 1) and decreased blood urea nitrogen (n = 2). The veterinarian conducted whole blood ethylene glycol (EG) tests, which were positive for all cats. There were no known EG exposures. All cats were treated for suspected EG toxicosis and fully recovered after 48 hours. Separately from the cats' case, the same food was voluntarily recalled by the manufacturer 5 days later due to a higher-than-formulated amount of choline chloride added to the food. The 4 cats' canned cat food was tested for choline, choline chloride, EG, diethylene glycol, and propylene glycol to look for causes of the positive whole blood EG test. The cat food contained an average of 165,300 ppm (165,300 mg/kg) choline and 221,600 ppm (221,600 mg/kg) choline chloride on a dry matter basis, which is at least 65 times the recommended choline amount for adult cats. No glycols were detected. This case documents suspected choline toxicosis in cats after consuming a commercial canned cat food with a higher-than-formulated amount of choline chloride, and it suggests that choline toxicosis may cause a positive result on some EG whole blood tests. Choline toxicosis could be a possible differential diagnosis when a cat has a positive EG test and no known exposure to antifreeze.

Pet Food-Associated Dietary Exogenous Thyrotoxicosis: Retrospective Study (2016-2018) and Clinical Considerations.

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.