It’s important for all of us pet parents of senior dogs to be aware of canine Cushing’s disease symptoms. Cushing’s disease is one of the most common endocrine disorders found in senior dogs. If your Old Buddy is exhibiting signs of, or is diagnosed with this disorder, this article will fill you in on the fundamental facts you should know.

Your dog’s endocrine system (much like your endocrine system) is made up of a network of glands. These glands secrete hormones that control and regulate growth and metabolism, as well as many other bodily functions.

Simply put, if one (or more) of your dog’s glands is not functioning properly, then an imbalance occurs in hormone levels. This can result in an endocrine disorder such as Cushing’s disease. This disease is also known as hypercortisolism or hyperadrenocorticism because of the overabundance of cortisol produced by the adrenal glands.

Which of my Old Buddy’s glands aren’t working properly?

Cushing’s disease happens when there is too much production of the hormone cortisol. Cortisol is known as the “flight or fight” hormone and it helps your old Buddy regulate stress among other things. It also aids in kidney function, helps regulate blood pressure and blood sugar levels, and is important for immune responses as well as metabolizing fat.

There are two different glands in Buddy’s body responsible for cortisol production and they are the pituitary gland and the adrenal glands. Cortisol is actually produced in the adrenal glands. The adrenals are two small glands located just forward of Buddy’s kidneys. His pituitary gland is located at the base of his brain.  Face of an Old Chocolate Lab Mix with Gray Muzzle

Although the hormone cortisol is produced in the adrenal glands, the pituitary gland is responsible for making the hormone that stimulates the adrenal glands to produce cortisol. This hormone is called adrenocorticotropic hormone (ACTH).

So when a Buddy’s cortisol level goes awry enough to cause Cushing’s disease, either his pituitary gland or his adrenal glands have been compromised and are not working as they should.

In most cases (87% of the time), it’s the pituitary gland

Although this article started with the ominous warning about owners of senior dogs becoming aware of canine Cushing’s disease symptoms, there is some good news. The most common cause of naturally occurring hyperadrenocorticism in dogs is a benign tumor on the pituitary gland. (Malignant tumors of the pituitary, which are tumors that can spread through the body, are much more unusual.)

Adrenal gland tumors are responsible for the other 13% or so of naturally occurring canine Cushing’s disease and have a 50/50 chance of being malignant or benign.

There is one other major cause of Cushing’s disease in dogs, and that is the long term use of certain drugs to treat inflammatory and/or autoimmune disorders in pets. Dexamethasone and prednisone are two culprits and even ear drops containing steroids can cause the condition if used persistently over time. This cause of the disease would be the ‘non-naturally occurring’ or ‘iatrogenic’ kind, meaning the disorder was caused by medical treatment.

So what are canine Cushing’s disease symptoms?

Below is a general list of common symptoms that can be indicative of Cushing’s disease in your dog. Please keep in mind that not all dogs with hypercortisolism (an excess of cortisol in their system) display all of these symptoms and some of them can be associated with other diseases. If you think you are seeing symptoms of this disease in your dog, a trip to your veterinarian is the next step. Your dog’s doctor should make a definitive diagnosis by way of blood and urine tests before treatment can be begin.

  • Increased thirst, water consumption and urination: You notice that Buddy always seems thirsty and you’re filling his water bowl more frequently. He may even feel the need to drink any water he finds. (If this is the case, be sure to bring fresh water with you on any outings or walks to keep him from drinking from unclean or toxic sources such as puddles or swimming pools.)
  • He’s hungrier too: Affected dogs have an increased appetite as well. You may find that he wants to eat more frequently or doesn’t seem satisfied with his normal volume of food.
  • Loss of muscle mass and pot-bellied abdomen: You realize that Buddy is starting to develop a potbelly. You know he hasn’t been guzzling beer and you know he isn’t pregnant, so this is likely a sign of the onset of Cushing’s. Loss of muscle mass is also a symptom, so you might see his spine or other bony areas becoming more prominent.
  • Changes in his behavior: Buddy is just not acting like his usual, lovable self. He seems downright irritable at times and doesn’t want to go on his regular walks. He acts like he just wants to lie around, yet can’t seem to get comfortable. Navigating stairs is becoming a problem for him; Instead of jumping up into his favorite chair, he just lies beside it.
  • Skin conditions: His once beautiful coat is getting thin and scraggly.Black Terrier with Hair Loss Along with the hair loss, you can see that the skin underneath looks dark and almost papery thin. He’s getting blackheads on his skin, especially in the abdominal area. You may also notice that his skin is slightly moist and sticky with a distinctive yeasty odor, all of which are indications of a secondary skin infection.
  • Excessive panting: Even when sitting comfortably at home in the air conditioning, Buddy is panting like he just came home from a long walk in hot weather. Increased respiratory rate in is a common clinical sign of Cushing’s disease. This excessive panting can also interfere with Buddy’s sleeping patterns, contributing to insomnia or restless naps.

The road to recovery

Now that you are aware of canine Cushing’s disease symptoms, you can be on the lookout for them, particularly if you have an older dog or one who has been treated with corticosteroids for an extended period of time. Whether your veterinarian has suspected Cushing’s disease upon examination of your pet, or you have alerted the vet to your suspicions, the treatment will depend on what the cause is.

The overall prognosis of a dog diagnosed with Cushing’s disease is good. Surgery is possible for a benign pituitary tumor, but this type of pituitary-induced Cushing’s is more commonly treated with two drugs, trilostane and mitotane. The disease is relatively easily managed with these drugs, but will likely need to be administered for the rest of your dog’s life.

Treating a tumor on the adrenal gland requires major surgery. If the surgery is successful and the tumor is benign, or has not metastasized, the dog will most likely regain normal good health. If surgery isn’t an option, many dogs can be treated successfully with medication.

The treatment of iatrogenic (medicine induced) Cushing’s is fairly straightforward and involves weaning the dog very slowly off of the steroid being given. This should be done in a very controlled manner, overseen by your veterinarian. Hormone replacement therapy may be required in the future.

As with most things in life, an ounce of prevention is worth a pound of cure; So if at any time in your precious pet’s life, your veterinarian suggests the usage of corticosteroids, be sure he or she includes a discussion about the potential risks of canine Cushing’s disease. Never be afraid to ask your vet questions (or any doctor for that matter).