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.

[1]  M. Peterson,et al.  Clinical Features and Treatment Outcomes of 41 Dogs with Sublingual Ectopic Thyroid Neoplasia , 2014, Journal of veterinary internal medicine.

[2]  G. Daniel,et al.  Thyroid scintigraphy in veterinary medicine. , 2014, Seminars in nuclear medicine.

[3]  M. Ridgway,et al.  Thyrotoxicosis in a dog induced by the consumption of feces from a levothyroxine-supplemented housemate. , 2013, The Canadian veterinary journal = La revue veterinaire canadienne.

[4]  F. Zeugswetter,et al.  Hyperthyroidism in dogs caused by consumption of thyroid-containing head meat. , 2013, Schweizer Archiv fur Tierheilkunde.

[5]  C. Mooney,et al.  Assessment of the value of quantitative thyroid scintigraphy for determination of thyroid function in dogs. , 2012, The Journal of small animal practice.

[6]  D. Roth,et al.  Ectopic thyroid tissue in the periaortic area, cardiac cavity and aortic valve in a Beagle dog - a case report. , 2012, Experimental and toxicologic pathology : official journal of the Gesellschaft fur Toxikologische Pathologie.

[7]  R. Neiger,et al.  Dietary hyperthyroidism in dogs. , 2012, The Journal of small animal practice.

[8]  A. Kappeler,et al.  Intracardiac ectopic thyroid adenoma in a dog , 2010, Veterinary Record.

[9]  M. Piechotta,et al.  Autoantibodies against thyroid hormones and their influence on thyroxine determination with chemiluminescence immunoassay in dogs , 2010, Journal of veterinary science.

[10]  S. Wasser,et al.  Non-invasive measurement of thyroid hormone in feces of a diverse array of avian and mammalian species. , 2010, General and comparative endocrinology.

[11]  L. Hendriks,et al.  Hyperthyroidism caused by excessive consumption of sausages. , 2010, The Netherlands journal of medicine.

[12]  B. Brisson,et al.  Ectopic thyroid carcinoma causing right ventricular outflow tract obstruction in a dog. , 2009, Journal of the American Animal Hospital Association.

[13]  C. Mooney,et al.  Quantitative thyroid scintigraphy in greyhounds suspected of primary hypothyroidism. , 2009, Veterinary radiology & ultrasound : the official journal of the American College of Veterinary Radiology and the International Veterinary Radiology Association.

[14]  W. Kittisupamongkol.  Hyperthyroidism or thyrotoxicosis? (November 2008) , 2009, Cleveland Clinic Journal of Medicine.

[15]  D. Fishbein,et al.  Thyrotoxicosis outbreak linked to consumption of minced beef and chorizo: Minas, Uruguay, 2003-2004. , 2008, Public health.

[16]  K. Uchida,et al.  Functional thyroid gland adenoma in a dog treated with surgical excision alone. , 2007, The Journal of veterinary medical science.

[17]  R. Page,et al.  Sodium iodide I 131 treatment of dogs with nonresectable thyroid tumors: 39 cases (1990-2003). , 2006, Journal of the American Veterinary Medical Association.

[18]  M. Peterson,et al.  BSAVA manual of canine and feline endocrinology , 2004 .

[19]  M. Parmar,et al.  Recurrent hamburger thyrotoxicosis. , 2003, CMAJ : Canadian Medical Association journal = journal de l'Association medicale canadienne.

[20]  R. Nachreiner,et al.  Prevalence of serum thyroid hormone autoantibodies in dogs with clinical signs of hypothyroidism. , 2002, Journal of the American Veterinary Medical Association.

[21]  R. Kemppainen,et al.  Effect of storage conditions on cortisol, total thyroxine, and free thyroxine concentrations in serum and plasma of dogs. , 1998, Journal of the American Veterinary Medical Association.

[22]  H. Feit,et al.  Thyrotoxicosis Factitia Veterinarius , 1997, Annals of Internal Medicine.

[23]  G. Daniel,et al.  Quantitative 99mTc-pertechnetate thyroid scintigraphy in normal beagles. , 1997, Veterinary radiology & ultrasound : the official journal of the American College of Veterinary Radiology and the International Veterinary Radiology Association.

[24]  S. Savastano,et al.  Usefulness of a chromatographic method to detect circulating antithyroid hormone autoantibodies in canine serum , 1996, Journal of endocrinological investigation.

[25]  R. Kemppainen,et al.  Autoantibodies to triiodothyronine and thyroxine in a golden retriever. , 1996, Journal of the American Animal Hospital Association.

[26]  E. Feldman,et al.  99mTc-pertechnetate imaging of thyroid tumors in dogs: 29 cases (1980-1992). , 1994, Journal of the American Veterinary Medical Association.

[27]  P. Vos,et al.  The measurement of fecal thyroxine in the diagnosis of thyrotoxicosis factitia. , 1993, Thyroid : official journal of the American Thyroid Association.

[28]  L. Braverman,et al.  Werner and Ingbar's the Thyroid: A Fundamental and Clinical Text , 1991 .

[29]  A. W. Layton,et al.  Hyperthyroidism associated with a thyroid adenoma in a dog. , 1991, Journal of the American Veterinary Medical Association.

[30]  G. Lantz,et al.  Surgical excision of ectopic thyroid carcinoma involving the base of the tongue in dogs: three cases (1980-1987). , 1989, Journal of the American Veterinary Medical Association.

[31]  P. Pinsky,et al.  Community outbreak of thyrotoxicosis: epidemiology, immunogenetic characteristics, and long-term outcome. , 1988, The American journal of medicine.

[32]  R. Nelson,et al.  Canine and Feline Endocrinology and Reproduction , 1987 .

[33]  R. Janssen,et al.  An outbreak of thyrotoxicosis caused by the consumption of bovine thyroid gland in ground beef. , 1987, The New England journal of medicine.

[34]  R. Rosenthal,et al.  Clinical and pathologic features of thyroid tumors in 26 dogs. , 1986, Journal of the American Veterinary Medical Association.

[35]  D. Lana,et al.  Aortic body tumour with adjacent ectopic thyroid tissue in a dog. , 1986, Journal of comparative pathology.

[36]  R. Kemppainen,et al.  Evidence for episodic but not circadian activity in plasma concentrations of adrenocorticotrophin, cortisol and thyroxine in dogs. , 1984, The Journal of endocrinology.

[37]  R. Jaenke,et al.  Ectopic Thyroid Carcinoma with Metastases in a Beagle Dog , 1982, Veterinary pathology.

[38]  I. Leav,et al.  Adenomas and carcinomas of the canine and feline thyroid. , 1976, The American journal of pathology.

[39]  K. Miyoshi,et al.  Clinical observations on thyreoidismus medicamentosus due to weight reducing pills in Japan. , 1971, Endocrinologia japonica.

[40]  E. Rose,et al.  Occult factitial thyrotoxicosis. Thyroxine kinetics and psychological evaluation in three cases. , 1969, Annals of internal medicine.