Dog Breeds Prone to Hypothyroidism: Risks & Care

Hypothyroidism is a common health disorder in dogs that significantly affects their metabolic function by interfering with thyroid gland hormone production. It usually results in a reduced level of thyroid hormones such as thyroxine (T4), leading to symptoms like weight gain, lethargy, and skin changes. There are several types of hypothyroidism in dogs, including primary, secondary, congenital, and neoplastic forms, with prevalence and causes varying among breeds. Typically, dogs show early signs between four and six years of age.

Breeds Most at Risk of Developing Hypothyroidism

While any dog, including mixed breeds, can develop hypothyroidism, research highlights that certain pure breeds are more genetically predisposed. Knowing these risks supports responsible ownership and early veterinary care.

• Dachshund puppies
• Labrador Retriever puppies
• Golden Retriever puppies
• Cocker Spaniel puppies
• Boxer puppies
• English Bulldog puppies
• Great Dane puppies
• Greyhound puppies
• Doberman Pinscher puppies
• Tibetan Terrier puppies (not in original list but recognised high risk breed)

Other breeds with moderate susceptibility include:

• Siberian Husky puppies
• Mastiff puppies
• Rottweiler puppies
• American Staffordshire Terrier puppies
• Border Collie puppies
• Maltese puppies
• Dalmatian puppies
• Weimaraner puppies
• Bernese Mountain Dog puppies
• Chinese Shar-Pei puppies

Secondary Hypothyroidism Explained

Secondary hypothyroidism in dogs is usually caused by a tumour affecting the pituitary gland or from cancers that impact the thyroid gland indirectly. While rare, it has been observed more commonly in breeds such as the Golden Retriever, Boxer, and Beagle. The presence of cancerous growths can suppress normal hormone production, leading to hypothyroid symptoms.

Neoplastic Hypothyroidism

This form results from abnormal growths directly on the thyroid gland or may arise from destruction of thyroid tissue causing iodine deficiency. Boxers and Giant Schnauzers are particularly prone. Diagnosing neoplastic hypothyroidism requires thorough veterinary evaluation and imaging.

Congenital Hypothyroidism

Often called juvenile onset hypothyroidism, this inherited form affects puppies from a young age. Breeds such as Toy Fox Terriers, Giant Schnauzers, and German Shepherd Dogs have been identified with a higher likelihood of passing this condition genetically. Responsible breeding practices help reduce incidence of congenital hypothyroidism by screening parent dogs.

The Importance of Responsible Breeding

Responsible and selective breeding is key to reducing the prevalence of congenital hypothyroidism. Breeders who focus on health screening and avoiding mating dogs known to be affected can significantly improve breed health over generations. Any prospective dog owner should seek reputable breeders who prioritise health and genetic testing to support this effort.

Early Diagnosis is Essential

Diagnosing hypothyroidism early improves treatment outcomes and quality of life. Vets use a combination of blood tests including total T4, free T4, and thyroid stimulating hormone (TSH) to confirm diagnosis. Some dogs may require additional tests for a definitive diagnosis. Early detection helps prevent complications like heart or neuromuscular problems.

Once diagnosed, lifelong hormone replacement therapy with levothyroxine is usually prescribed. Regular veterinary follow-up ensures the medication dosage remains effective and safe as the dog ages.

Additional Tips for Owners

• Watch for signs such as increased weight, lethargy, hair loss, or skin changes, and seek prompt veterinary advice.
• Keep comprehensive medical records to share with your vet for ongoing monitoring.
• Maintain a balanced diet and regular exercise routine to support overall health.

Conclusion

Understanding which dog breeds are prone to hypothyroidism and recognising the importance of early diagnosis helps dog owners provide better care throughout their pet’s life. Responsible breeding remains crucial to limiting inherited cases, while timely treatment enables most affected dogs to live comfortable, happy lives. Staying informed and closely working with a vet ensures the best outcomes for dogs challenged by hypothyroidism in 2025.