Article Text

Download PDFPDF
Juvenile hyperthyroidism in a dog
  1. Christina Maunder1,
  2. Ed J Friend2,
  3. Michael Day3 and
  4. Christopher Warren-Smith1
  1. 1 Veterinary School, University of Bristol, Bristol, UK
  2. 2 Highcroft Veterinary Referrals, Bristol, UK
  3. 3 Veterinary Pathology, Infection and Immunity, University of Bristol, Bristol, UK
  1. Correspondence to Christina Maunder; c.maunder{at}


Hyperthyroidism is the most common endocrinopathy in cats, and most cases are caused by multinodular hyperplasia or follicular cell adenoma, although thyroid carcinomas occur infrequently. Hyperthyroidism is rare in dogs, and most cases are caused by functional thyroid carcinomas. There are case reports of canine hyperthyroidism secondary to exogenous sources, and rarely thyrotoxicosis can be seen with therapeutic doses of levothyroxine prescribed for hypothyroidism. A case of juvenile hyperthyroidism has been reported in a cat and a histopathological diagnosis of diffuse thyroid hyperplasia was made. This is the first reported case of functional eutopic thyroid tissue in a young dog. Histopathological examination reported bilateral hyperplastic change in the thyroid glands, similar to the case of feline juvenile hyperthyroidism.

  • canine
  • thyroxine
  • hyperplasia
View Full Text

Statistics from


  • Contributors CM was the major contributor in writing the manuscript and collated the data. CW-S analysed and interpreted the diagnostic imaging data and provided the image for publication. MD performed and reported the histopathological data. EJF performed the surgery, provided the image and reported the surgical findings. All authors read and approved the manuscript.

  • Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.

  • Competing interests None declared.

  • Provenance and peer review Not commissioned; externally peer reviewed.

  • Data statement Data can be obtained by contacting the corresponding author.

Request Permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.