Diagnosing Canine Thyroid Disease

Thyroid disease is the most common endocrine disease in dogs and can be very difficult to diagnose, because the symptoms can be attributed to many illnesses and may even be contradictory to one another.

Development of Thyroid Disease

The most common form of thyroid disease, also referred to as thyroiditis, is considered to be hereditary. Though a dog without any family history of thyroid problems can acquire them later in life, evidence shows that a large portion of dogs afflicted with thyroid disease have a genetic predisposition for it.

There are several breeds that show a higher rate of thyroid problems than others. These include golden retrievers, rottweilers, doberman pinschers, boxers, German shepherds, akitas, English sheepdogs, Irish setters, Great Danes, beagles, borzois and cocker spaniels. Prevention of this disease includes screening for the disease before breeding and limiting the breeding of those dogs with thyroid problems.

Symptoms of Thyroid Disease

The thyroid is a gland in mammals that controls many different processes such as metabolism, growth and development. Most thyroid disease develops later in your dog's life and affects his metabolism. If it affects puppies, it can prevent proper development.

One of the biggest problems in diagnosing thyroid disease is that the symptoms vary greatly between dogs. Some dogs lose weight and have increased appetite and exercise level, while others gain weight and experience lethargy. Other symptoms include:

  • Skin lesions
  • Dull or greasy coat
  • Constipation
  • Diarrhea
  • Cold intolerance
  • Exercise intolerance
  • Skin odor
  • Hair loss
  • Changes in personality, such as increased aggression or anxiety.

Because these symptoms may be difficult to detect, any unexplained, prolonged behavior changes in your dog should be checked out by a veterinarian. If tests are inconclusive, ask for a full blood panel.

Diagnosis of Thyroid Disease

The only way to definitely diagnose thyroid disease is a blood panel that measures levels of T3 and T4 in your dog's body. These hormones are produced only by the thyroid gland, so any deficiencies in these levels indicates a potential problem.

When reading the results of the thyroid test, you will see that the normal range is very large. If your dog is in the lower half of the range and the symptoms continue or worsen, have him retested within a year to make sure a condition hasn't appeared.

Treatment of Thyroid Disease

If your dog's thyroid isn't producing the correct amount of hormones, this is easily treated with medication. There are several types of medications available, such as soloxine and levothyroxine, that regulate the levels of thyroid hormones in your dog's system.

If your dog is placed on thyroid medication, don't expect the symptoms to go away overnight. Hormone regulation takes some time, so your dog actually might become more lethargic or gain more weight while adjusting to the medication.

Thyroid disease can be difficult to diagnose, but it is still harmful because of the importance that the thyroid plays in the bodies of mammals throughout their life. If your dog has experienced some changes in behavior, appetite or energy level, or if you have noticed a change in the quality of your dog's coat or skin, visit your veterinarian for a blood panel.