Have you noticed your older pooch looking a bit plump around the middle? A pot-bellied appearance is one of the most common signs of Cushing’s Disease in dogs. Also known as hyperadrenocorticism, Cushing’s occurs when the body produces too much cortisol, a hormone that helps regulate many important functions. Cushing’s is the opposite of Addison’s disease, where the body doesn’t make enough cortisol. Continue reading to learn about Cushing’s and how it impacts dogs.
Symptoms of Cushing’s Disease in Dogs
As with any medical concern, noticing these signs and symptoms of Cushing’s disease means it’s time to make a trip to the vet:
- Hair Loss: Many dogs with Cushing’s experience hair loss/thinning, particularly along their back and belly, while their head or legs aren’t affected.
- Poor Hair Regrowth After Shaving: Dogs that require regular grooming may have slow or uneven regrowth of fur. New growth may be more thin and brittle than before.
- Pot-Bellied Appearance: Cushingoid dogs may develop a “pot-belly,” as body fat moves to the area. The skin often appears thinner around the abdomen, with blood vessels becoming more visible.
- Increase in Hunger or Thirst: Cushing’s can cause dogs to feel so hungry they raid the trash or steal food off your plate. They might also be very thirsty and start having accidents in the house.
- Muscle Weakness: Cushing’s can also cause muscle loss. Your dog might appear more bony and feel weaker than usual. They may struggle to jump onto furniture, tire more quickly, or hesitate during walks or when climbing stairs.
- Lethargy: Dogs with Cushing’s may seem more tired, sleep more, or lose interest in their usual activities.
- Excessive Panting: Most dogs pant during exercise or when excited. Cushingoid dogs may pant frequently, even at rest.
- Recurring Infections: Cushingoid dogs may take longer to recover from illness and are more prone to infections (especially urinary tract infections).
- Seizures: In rare cases when Cushing’s is caused by a tumor near the brain that grows large enough to press against it, the dog may experience seizures.
Not all dogs will show every symptom, but closely monitoring your pup’s behavior, attitude, and appearance can help you realize there’s a problem more quickly.
Causes of Cushing’s Disease in Dogs
Cushing’s happens for two primary reasons in dogs: pituitary gland tumors and adrenal gland tumors. According to the Merck Veterinary Manual, 85-90% of dogs with Cushing’s disease have a pituitary gland tumor while the remaining 10-15% have adrenal gland tumors. However, this disease can sometimes be caused by long-term use of steroidal medication like prednisone.
Pituitary Gland Tumors in Dogs
In most cushingoid pups, the cause is a small, noncancerous (benign) tumor on the pituitary gland. This gland is located near the brain and controls important functions like growth, metabolism, and stress response. Occasionally, the tumor grows large enough to press against the brain and cause seizures.
Adrenal Gland Tumors in Dogs
In a few cases, Cushing’s disease results from a tumor on one of the adrenal glands. These glands sit on top of the kidneys (one on each kidney) and produce hormones like cortisol. When a tumor forms in these glands, it can lead to an overproduction of cortisol. Adrenal tumors can be benign or malignant (cancerous) and often require surgical removal.
Iatrogenic Cushing’s Disease in Dogs
This form of Cushing’s disease is caused by giving your buddy corticosteroid medications, like prednisone, to treat other health issues. Steroids mimic the effects of cortisol and can lead to Cushing’s symptoms.
How Do Vets Diagnose Cushing’s in Dogs?
Diagnosing Cushing’s disease can be challenging since its symptoms can resemble those of other conditions. If your vet suspects your pup has Cushing’s, they’ll start with a nose-to-tail physical exam and review your dog’s medical history.
After the exam and a discussion with you, your vet may recommend testing. Blood and urine tests can help your vet check for elevated cortisol levels, which can point to Cushing’s disease in your dog.
Adrenocorticotropic Hormone (ACTH) Stimulation
Frequently called an ACTH-stim test, this procedure helps assess your dog’s adrenal gland function. This test involves the following steps:
- Initial Blood Draw: Your vet will take a blood sample to measure baseline cortisol levels.
- Injection: Next, your vet will give your dog an injection of a synthetic form of ACTH. This hormone activates the adrenal glands, causing them to produce cortisol.
- Second Blood Draw: A second blood sample, drawn about 1–2 hours after the injection will also measure cortisol levels. If the level is significantly elevated, your dog likely has Cushing’s disease.
Low-Dose Dexamethasone Suppression Test (LDDST)
The LDDST is another important test that evaluates how your dog’s body responds to dexamethasone, a type of steroid.
- Initial Blood Draw: Your vet will take a blood sample to measure baseline cortisol levels.
- Injection: Next, your vet will give your dog an injection of dexamethasone. This hormone naturally reduces cortisol production in healthy dogs.
- Second Blood Draw: A second blood sample, drawn about 4–8 hours after the injection will also measure cortisol levels. If the level remains high, your dog likely has Cushing’s disease.
See also
Urine Tests
Your vet may also recommend urine tests to confirm your dog’s diagnosis of Cushing’s disease. A urine cortisol-to-creatinine ratio (UCCR) test helps evaluate cortisol levels related to creatinine (a waste product found in urine). If there is more cortisol than creatinine in your dog’s urine, they may have Cushing’s.
Imaging
In some cases, your vet may suggest imaging such as X-rays or ultrasound to examine the adrenal glands. This can help them determine if they are abnormal or have developed tumors. A CT scan can help identify a pituitary gland tumor, but this test is very expensive, so vets don’t recommend it often.
Treatment for Cushing’s in Dogs
If your dog has Cushing’s, the treatment typically depends on what’s the cause. Regardless of the treatment, regular follow-ups will be necessary to monitor their response to treatment. Although treatment can help, there is no cure for Cushing’s disease.
For pituitary gland tumors, the most common treatment is medication. Trilostane (brand name Vetoryl) and mitotane help reduce cortisol production. Adrenal tumor patients may be candidates for surgery to remove the tumor(s). In cases of iatrogenic Cushing’s, the vet will gradually decrease the steroid dosage to help reduce symptoms.
What Dogs Breeds Get Cushing’s?
Common breeds of dogs that get Cushing’s include Miniature Poodles, Dachshunds, Boxers, Boston Terriers, Yorkshire Terriers, and Staffordshire Terriers. However, any dog can become a cushingoid.
High Cortisol Doesn’t Mean Low Hope
Discovering your dog has Cushing’s disease can be heartbreaking. But understanding the condition and getting a proper diagnosis are the first steps toward managing your pup’s health. While Cushing’s disease is a serious concern, it doesn’t have to define your dog’s future. With the right treatment and your vet’s guidance, you can keep cortisol levels low, maintain high hopes, and enjoy a long, fulfilling life with your canine companion!
