December 21, 2016

Thyroiditis in a Group of Laboratory Dogs: A Study of 167 Beagles

     This article is trying to answer why changes in the thyroid glands of Beagles happen on such a large scale and what causes them. It is interesting because the Beagle is widely used in many studies as a standard laboratory animal. These changes are usually interpreted as inflammatory but few research has been published regarding inflammatory lesions of the canine thyroid gland. A possible explanation is that Thyroiditis occurs spontaneously in the beagle dog breed. For 2 years,  a group of purebred Beagles were fed various foods preserved by irradiation. The dogs that were fed irradiated foods were fed irradiated foods to the extent of 20 to 35% of their diet by dry weight. The rest of their diet consisted of commercial dog food with added supplements designed to achieve proper nutritional balance. There was a control group that was not fed any irradiated foods. At the end of the 2 year feeding period the dogs were sacrificed and necropsies were performed.

     The study found sufficient histologic evidence to conclude Thyroiditis in 16.2% of all the Beagles studied with equal rates of Thyroiditis found in dogs fed Irradiated foods and the control group. This means Thyroiditis will occur in Beagles regardless of diet.

Reviewed by Jonathan Guzman