What is Cushing’s Disease?

Cushing’s Disease (hyperadrenocorticism) develops when your dog has an overproduction of the hormone cortisol.

How did my dog get Cushing’s Disease?

A dog produces most of its cortisol hormone through their adrenal glands.If a tumor is present, it can cause an over-secretion of the cortisol hormone resulting in Cushing’s Disease. Adrenal tumors are responsible for approximately 20% of Cushing’s Disease that is diagnosed. The other 80% of Cushing’s Disease patients result from a tumor on the dog’s pituitary gland. The pituitary gland is located in the brain and when a tumor is present it can send signals to the adrenal glands to increase the production of cortisol, which results in Cushing’s Disease. Less common is the occurrence of iatrogenic Cushing’s Disease, which results from long term use of corticosteroids, such as prednisone.

What is Cushing’s Disease?

Cushing’s Disease (hyperadrenocorticism) develops when your dog has an overproduction of the hormone cortisol.

How did my dog get Cushing’s Disease?

A dog produces most of its cortisol hormone through their adrenal glands.If a tumor is present, it can cause an over-secretion of the cortisol hormone resulting in Cushing’s Disease. Adrenal tumors are responsible for approximately 20% of Cushing’s Disease that is diagnosed. The other 80% of Cushing’s Disease patients result from a tumor on the dog’s pituitary gland. The pituitary gland is located in the brain and when a tumor is present it can send signals to the adrenal glands to increase the production of cortisol, which results in Cushing’s Disease. Less common is the occurrence of iatrogenic Cushing’s Disease, which results from long term use of corticosteroids, such as prednisone.

Symptoms

Cushing’s Disease is more prominently found in older pets and oftentimes the disease is mistaken for the natural aging process. Here is a list of the most common signs of Cushing’s Disease:

  • Increased/excessive water consumption known as polydipsia
  • Increased/excessive urination known as polyuria
  • Urinary accidents in previously house-trained dogs
  • Increased/excessive appetite known as polyphagia
  • The appearance of food-stealing/guarding, begging, trash dumping, etc.
  • Sagging, bloated, pot-bellied appearance
  • Weight gain or its appearance, due to fat redistribution
  • Loss of muscle mass, giving the appearance of weight loss
  • The bony, skull-like appearance of the dog’s head
  • Exercise intolerance, lethargy, general or hind-leg weakness

  • New reluctance to jump on furniture or people
  • Excess panting, seeking cool surfaces to rest on
  • Symmetrically thinning hair or baldness on the torso
  • Other coat changes like dullness, dryness
  • Slow regrowth of hair after clipping
  • Thin, wrinkled, fragile, and/or darkly pigmented skin
  • Easily damaged/bruised skin that heals slowly
  • Hard, calcified lumps in the skin
  • Susceptibility to infections (especially skin and urinary)
  • Diabetes, pancreatitis, seizures

Your pet does not have to express each symptom to be diagnosed with Cushing’s Disease.

Symptoms

Cushing’s Disease is more prominently found in older pets and oftentimes the disease is mistaken for the natural aging process. Here is a list of the most common signs of Cushing’s Disease:

  • Increased/excessive water consumption known as polydipsia
  • Increased/excessive urination known as polyuria
  • Urinary accidents in previously house-trained dogs
  • Increased/excessive appetite known as polyphagia
  • The appearance of food-stealing/guarding, begging, trash dumping, etc.
  • Sagging, bloated, pot-bellied appearance
  • Weight gain or its appearance, due to fat redistribution
  • Loss of muscle mass, giving the appearance of weight loss
  • The bony, skull-like appearance of the dog’s head
  • Exercise intolerance, lethargy, general or hind-leg weakness
  • New reluctance to jump on furniture or people
  • Excess panting, seeking cool surfaces to rest on
  • Symmetrically thinning hair or baldness on the torso
  • Other coat changes like dullness, dryness
  • Slow regrowth of hair after clipping
  • Thin, wrinkled, fragile, and/or darkly pigmented skin
  • Easily damaged/bruised skin that heals slowly
  • Hard, calcified lumps in the skin
  • Susceptibility to infections (especially skin and urinary)
  • Diabetes, pancreatitis, seizures

Your pet does not have to express each symptom to be diagnosed with Cushing’s Disease.

How does my veterinarian diagnose Cushing’s Disease?

Your dog’s outward appearance and behavior will indicate to the veterinarian that there is a need for further diagnostics to determine if your pet has Cushing’s Disease. Further diagnostic tests can include:

  • Bloodwork to determine if your pet has elevated liver enzymes, cholesterol, and blood glucose levels, etc.
  • Urinalysis, looking for high levels of protein and low specific gravity indicating diluted urine.
  • Ultrasound to look for an enlarged liver or atrophied adrenal gland.

Your veterinarian’s exam and these diagnostic procedures can suggest the presence of Cushing’s but specific lab tests can help to further pinpoint a diagnosis. These tests include a urine cortisol/creatinine ratio test, ACTH stimulation test and low dose dexamethasone suppression test. However, there is no single test to diagnose Cushing’s Disease.

Prognosis

The short-term prognosis is very good. Once treated, one would expect symptoms of Cushing’s to fully resolve over the course of 4 – 6 months. Excess drinking and urinating will reduce rather quickly. It may take several months for hair and coat to improve. Dogs are generally more comfortable after the disease is under control and may live happily for years.

Left untreated, Cushing’s Disease will progress. As excess cortisol can suppress the function of the immune system, patients affected are prone to various infections. They are also predisposed to develop hypothyroidism, pancreatitis, diabetes, seizures, hypertension, congestive heart failure, blood clots, and liver and kidney failure.

Prognosis

The short-term prognosis is very good. Once treated, one would expect symptoms of Cushing’s to fully resolve over the course of 4 – 6 months. Excess drinking and urinating will reduce rather quickly. It may take several months for hair and coat to improve. Dogs are generally more comfortable after the disease is under control and may live happily for years.

Left untreated, Cushing’s Disease will progress. As excess cortisol can suppress the function of the immune system, patients affected are prone to various infections. They are also predisposed to develop hypothyroidism, pancreatitis, diabetes, seizures, hypertension, congestive heart failure, blood clots, and liver and kidney failure.

Treatment Expectations

Depending on which form of Cushing’s Disease your pet has will have an impact on how it is treated.

  • For a Pituitary Tumor your pet will most likely be treated with oral medication like Vetoryl or Lysodren and monitored every 6 – 12 months.
  • If an adrenal tumor is the cause of your pet’s diagnosis, surgery and further diagnostics will be suggested to remove the tumor and rule out cancer.
  • If your pet’s current steroid medication is causing them to have Cushing’s Disease, your veterinarian will alter your pet’s medication and monitor their progress.