Exogenous thyrotoxicosis in dogs attributable to consumption
of all-meat commercial dog food or treats containing excessive thyroid hormone
submitted by Patty Ewing
S K-M photo, Patty & MACH 3 Danablu
Hi Susan-
An article was just published in the Journal of the American Veterinary Medical Association by a few of my colleagues that I thought might make for an interesting feature in the Wrinkler. I pasted the article summary, abstract and my somewhat simplified interpretation of the article below. If you want the full length article, let me know and I'll email it to you. Patty
Summary of "Exogenous thyrotoxicosis in dogs attributable to consumption of all-meat commercial dog food or treats containing excessive thyroid hormone: 14 cases (2008-2013)."
Objective
To describe findings in dogs with exogenous thyrotoxicosis attributable to consumption of commercially available dog foods or treats containing high concentrations of thyroid hormone.
Design
Retrospective and prospective case series.
Animals
14 dogs. Procedures-Medical records were retrospectively searched to identify dogs with exogenous thyrotoxicosis attributable to dietary intake. One case was found, and subsequent cases were identified prospectively. Serum thyroid hormone concentrations were evaluated before and after feeding meat-based products suspected to contain excessive thyroid hormone was discontinued. Scintigraphy was performed to evaluate thyroid tissue in 13 of 14 dogs before and 1 of 13 dogs after discontinuation of suspect foods or treats. Seven samples of 5 commercially available products fed to 6 affected dogs were analyzed for thyroxine concentration; results were subjectively compared with findings for 10 other commercial foods and 6 beef muscle or liver samples.
Results
Total serum thyroxine concentrations were high (median, 8.8 μg/dL; range, 4.65 to 17.4 μg/dL) in all dogs at initial evaluation; scintigraphy revealed subjectively decreased thyroid gland radionuclide in 13 of 13 dogs examined. At ≥ 4 weeks after feeding of suspect food or treats was discontinued, total thyroxine concentrations were within the reference range for all dogs and signs associated with thyrotoxicosis, if present, had resolved. Analysis of tested food or treat samples revealed a median thyroxine concentration for suspect products of 1.52 μg of thyroxine/g, whereas that of unrelated commercial foods was 0.38 μg of thyroxine/g.
Conclusions and Clinical Relevance:
Results indicated that thyrotoxicosis can occur secondary to consumption of meat-based products presumably contaminated by thyroid tissue, and can be reversed by identification and elimination of suspect products from the diet.
http://www.bioportfolio.com/resources/pmarticle/1128695/Exogenous-thyrotoxicosis-in-dogs-attributable-to-consumption-of-all-meat-commercial-dog.html
Abstract
Journal of the American Veterinary Medical Association
January 1, 2015, Vol. 246, No. 1, Pages 105-111
doi: 10.2460/javma.246.1.105
Exogenous thyrotoxicosis in dogs attributable to consumption of all-meat commercial dog food or treats containing excessive thyroid hormone: 14 cases (2008–2013)
Michael R. Broome, DVM, MS; Mark E. Peterson, DVM; Robert J. Kemppainen, DVM, PhD; Valerie J. Parker, DVM; Keith P. Richter, DVM
Advanced Veterinary Medical Imaging, 3047 Edinger Ave, Tustin, CA 92780. (Broome); Animal Endocrine Clinic, 21 W 100th St, New York, NY 10025. (Peterson); Department of Anatomy, Physiology and Pharmacology, College of Veterinary Medicine, Auburn University, Auburn, AL 36849. (Kemppainen); Department of Veterinary Clinical Sciences, College of Veterinary Medicine, The Ohio State University, Columbus, OH 43210. (Parker); Veterinary Specialty Hospital, 10435 Sorrento Valley Rd, San Diego, CA 92121. (Richter)
Presented in abstract form at the 34th Annual Veterinary Medical Forum of the American College of Veterinary Internal Medicine, Nashville, Tenn, June 2014.
The authors thank Dr. Tad B. Coles for assistance with writing and editing this manuscript.
Address correspondence to Dr. Broome (mrbroome@avmi.net).
Patty's interpretation:
The "gullet" refers to the animal's esophagus, and "thyrotoxicosis" is hyperthyroidism, or excess thyroid hormone:
The article describes cases of thyrotoxicosis in dogs that consumed some types of all-meat commercial dog food or treats. The products were presumably contaminated with beef thyroid gland. This happens when gullet trimmings are included in dog food or treats. The gullet trimmings are often contaminated with thyroid gland so the dog that consumes them can get excessive blood/tissue levels of functional thyroid hormone.
The article mentions in the discussion that in August 1985, following an outbreak of thyrotoxicosis in people, the USDA ordered that the procedure for gullet trimming for the collection of edible meat products be discontinued at all meat packing plants, which resolved the problem in people.
But currently, USDA lists beef gullets and tracheas as acceptable for use in pet foods. This highlights the importance of knowing the meat source if you feed meat to your dogs.
We should be advocating for stricter regulation of pet food production.