Cushing's Disease & Hypothyroidism

Just like you, your dog’s endocrine system has seemingly boundless duties—from regulating mood to body temperature to how fast he grows, according to the Mayo Clinic. As such, it’s easy to see how a disease of the endocrine system, such as Cushing’s disease or hypothyroidism, can interfere with your dog’s normal functioning. And both of these conditions are quite common in dogs, according to the Merck Veterinary Manual.

  1. Basics

    • Both Cushing’s and hypothyroidism involve either too little or too much of a hormone being made. In the case of Cushing’s, too much of the hormone cortisol (known as the stress or "fight-or-flight" substance) is produced, according to MVM. It’s the other way around with hypothyroidism; when your dog has the condition, he makes too little of the thyroid hormone.

    Risks

    • As your dog gets older, his chances of developing Cushing&'s go up. The average dog with Cushing&'s is 6 or 7 years old. Specific breeds are not as prone to Cushing&'s, and whether your dog is male or female doesn&'t make a difference. When it comes to hypothyroidism, your dog&'s gender may not make a difference, but females that have been spayed are at greater risk, as are certain breeds, such as Irish Setters, cocker spaniels and golden retrievers.

    Symptoms

    • A telltale sign of Cushing&'s is, as with humans who suffer from the disease, a pot belly, as high cortisol levels tend to cause fat to accumulate in the abdomen. Other signs include extreme thirst and frequent urination, as well as excessive panting and hair loss. Your dog may have hypothyroidism if he gains a lot of weight for no apparent reason and appears listless and weak. A coat that lacks sheen and spots or blotches on the skin have also been noted.

    Diagnosis

    • It&'s not enough for your dog to show the "classic" symptoms of Cushing&'s disease. Along with examining your pet&'s medical history, your veterinarian will also run a gamut of tests--including a blood chemistry panel that examines various components of the blood and a urinalysis, which evaluates elements like how concentrated your pet&'s urine is and its color. Hypothyroidism is easier to diagnose, as a blood test can check for the levels of thyroid hormones T3 and T4.

    Treatment

    • If an abnormal growth on the pituitary gland is causing your dog to make too much cortisol, it may have to be removed. In far fewer cases, an adrenal gland tumor is responsible and may have to be surgically removed. There are also non-surgical options, which include medications your dog may take by mouth, such as Lysodren. Your dog stands a good chance of beating hypothyroidism by taking an oral medication that mimics the naturally-occurring thyroid hormone that his body doesn&'t make in sufficient supply on its own.