Causes of Thyroid Problems in Dogs

Thyroid problems in dogs is a rather common issue, especially in canines that inherit certain genes linked to developing thyroid problems. In most cases, thyroid conditions can be categorized as either hyperthyroidism or hypothyroidism. In hyperthyroidism, too many hormones are being produced in the body. Hypothyroidism, on the other hand, means that not enough hormone is being supplied. 

The thyroid produces hormones referred to as T3 and T4, and these hormones are an important part of your pet's metabolism. Hormone levels that are too high or too low can result in:

  • digestive problems
  • weight issues
  • heart conditions
  • reproductive issues
  • skin problems

While canines can have either hyperthyroidism or hypothyroidism, hypothyroidism is much more likely to develop in dogs than hyperthyroidism. 

Canine Hypothyroidism

Hypothyroidism in dogs occurs when the thyroid gland begins a process called atrophy or when lymphocytes enter the thyroid gland and harm the tissue. There is no known cause of why this occurs in certain dogs, but it is believed that some breeds are more prone to hypothyroidism than others. Boxers, Beagles, Terriers, Poodles, Spaniels, Cocker Spaniels, German Shepherds, Labrador Retrievers, and other mixed breeds have a higher risk of developing hypothyroidism in their life time. 

Symptoms of Hypothyroidism

There are various types of signs and symptoms to watch out for if you believe your pet is suffering from hypothyroidism. These symptoms may include the following:

  • Slow heart rate
  • Unexplained weight gain
  • Thin hair
  • Loss of energy
  • Ear problems
  • Confusion
  • Hair loss 
  • Inability to exercise
  • Cold intolerance
  • Scabs or rashes on the skin
  • Spots on skin 
  • Lethargy
  • High cholesterol
  • Infertility
  • Eye problems

If you notice any of these common signs of hypothyroidism in your dog, contact your veterinarian for a proper diagnoses and treatment. 

Diagnosing Canine Hypothyroidism

A veterinarian will diagnose this condition by testing the levels of hormones within your pet's body. If the levels are considered low, hormone replacement treatment will likely be used. 

Canine Hyperthyroidism

Unfortunately, the most common cause of hyperthyroidism in dogs is thyroid cancer. The cancer forms when a tumor or mass develops on the thyroid gland and releases too many hormones. These tumors are usually quick to grow and large. Thyroid cancer is a very serious disease in dogs with a high risk of fatality. Surgery is normally required to remove the mass or tumor, but the survival rate can be low. As stated earlier, hyperthyroidism is not very common in dogs. 

Symptoms of Hyperthyroidism in Dogs

There are not as many signs and symptoms with hyperthyroidism as there are with hypothyroidism in dogs. The most common signs of hyperthyroidism in canines are as follows:

  • Unexplained weight loss
  • Abnormal heart rate
  • Increase in appetite