Cushing’s disease in dogs is a common and manageable condition with prompt veterinary intervention. In fact, many dogs start to feel and act more like themselves within a few days to a few weeks after starting treatment.
Whether your dog has been recently diagnosed or you suspect they may have Cushing’s disease, we’re breaking down all of the facts for you below.
Key Points
- Cushing’s disease in dogs is a hormonal condition where the adrenal glands make too much cortisol.
- The most common signs of Cushing’s disease in dogs are panting as well as increased appetite, weight gain, water consumption, and urination.
- The main causes of Cushing’s disease in dogs are a pituitary or adrenal gland tumor or excessive dosage of steroid medication over time.
- Your vet will typically run multiple lab tests in addition to a physical exam to determine the exact cause and the right treatment plan.
What is Cushing’s disease in dogs?
Cushing’s disease (or Cushing’s syndrome) is a hormonal condition where your dog’s adrenal glands produce an excessive amount of cortisol (cortisone) hormone. This condition is also known as hyperadrenocorticism aka hyper (over-active), adreno (adrenal gland), corticism (outer part of the gland).
Cortisol affects every system in the body and is also called the stress hormone because it is used in fight, flight, or freeze responses. Cortisol also helps regulate blood sugar and metabolism, reduces inflammation, and is involved in memory. When there is too much cortisol in the system, however, things start to get out of balance.
The signs of Cushing’s disease in dogs
While Cushing’s disease usually happens in older dogs, it can affect any breed. Studies show that some breeds, like Poodles, Dachshunds, Boston Terriers, German Shepherds, and Beagles, get Cushing’s more often than others.
The most common signs of Cushing’s disease in dogs include dog panting as well as increased appetite, weight gain, water consumption, and urination. Additional clinical signs of hyperadrenocorticism in dogs can include:
- Recurrent skin or urinary tract infections
- Muscle weakness
- Pot bellied appearance
- Excessive panting
- Hair loss on the trunk
- Hyperpigmentation or darkening of the skin
- Chronic skin infections
- Thin skin
- Calcinosis cutis
- Facial nerve palsy
What are the causes of Cushing’s disease in dogs?
Dogs and humans have a gland in the brainstem called the pituitary gland. This gland sends messages to the adrenal glands to produce hormones, like cortisol. Now, Cushing’s disease occurs when the adrenal glands make too much cortisol. But why?
There are three typical causes of Cushing’s in dogs: pituitary gland tumors, adrenal gland tumors, and administering excessive amounts of steroid medications.
Pituitary gland tumors
A pituitary gland tumor (benign or cancerous) is one of the main culprits behind Cushing’s disease in dogs. This tumor causes the pituitary gland to overproduce the Adrenocorticotropic hormone (ACTH), triggering the adrenal glands to produce cortisol excessively.
Pituitary gland tumors come in different sizes, and their effects on the body can vary. Apart from the symptoms of Cushing’s disease, a larger tumor can press against other organs, causing additional signs of discomfort.
Most dogs with benign pituitary gland tumors can live normal lives for many years. Your vet can help manage the adrenal gland function with medication and close medical supervision. However, if the pituitary tumor progresses it can cause neurological symptoms that reduce your pet’s chance of recovery. Similarly, if your dog has a cancerous tumor, their prognosis may not be as good.
Adrenal gland tumors
Adrenal gland tumors can also cause Cushing’s disease in dogs. This tumor can also be either benign (not harmful) or malignant (cancerous). For benign adrenal gland tumors, surgically removing the tumor may help cure the disease. However, if it’s cancerous, surgery may help only for a while, and the prognosis may not be as good.
Excessive steroid medications
Steroids are commonly prescribed to treat inflammatory conditions. However, if your pet takes an excessive amount of steroid medications (injections, pills, creams, etc.), signs of Cushing’s disease can result. This type of Cushing’s disease in dogs is called iatrogenic Cushing’s disease or “False Cushing’s” and can actually be cured by simply lowering the dose of medication.
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How is Cushing’s disease in dogs diagnosed?
If you suspect your dog might have Cushing’s, schedule an appointment with your veterinarian ASAP.
Your vet will do a physical exam and run necessary laboratory tests to rule out other health problems and get to the root cause of your dog’s Cushing’s diagnosis. These lab tests include:
Blood tests
The typical blood tests or full chemistry panel that screens for Cushing’s include:
- Complete blood count to check the blood cells.
- Blood chemistry and bloodwork to check the function of internal organs.
- Urinalysis to check kidney function.
- Urine culture to check for urinary tract infections, and urine concentration.
ACTH stimulation test
The ACTH stimulation test helps determine if your furry friend has Cushing’s disease by checking how their adrenal glands respond to the hormone ACTH. To do this, your vet will measure your dog’s cortisol levels from a blood sample. Your vet will then inject ACTH (synthetic version) and collect another sample after an hour.
Healthy dogs have mild cortisol increase after synthetic ACTH injection, typically between 300-400 nmol/l after 1 hour. Dogs with Cushing’s have much higher cortisol levels, usually above 550-600 nmol/l.
Low dose dexamethasone suppression test
During this test, your dog will get a dexamethasone injection. Dogs without Cushing’s disease will have low cortisol levels after the injection. This is because dexamethasone stops the production of cortisol in the adrenal glands.
However, dogs with Cushing’s disease will have high cortisol levels even after receiving dexamethasone, as the drug can’t suppress the excess cortisol produced by Cushing’s.
Additional diagnostics for Cushing’s disease in dogs
Bear in mind that your vet may need some time to diagnose your dog correctly for Cushing’s disease. Your vet may order additional adrenal function tests, urine cortisol creatinine test, and a high-dose dexamethasone suppression test to determine the cause of the disease.
If your dog is diagnosed with Cushing’s, your vet may recommend an abdominal ultrasound to measure the adrenal glands. This ultrasound may help pinpoint whether the problem is in the pituitary gland or adrenal glands. It is an important test as the treatment for each type differs.
An ultrasound can also help rule out other conditions like gastrointestinal disease, liver tumors, gallbladder disease, bladder stones, or chronic inflammatory liver disease.
After running these tests, your vet will check for clues like high cholesterol, decreased BUN levels, and elevated liver enzymes in the test results. I know it can be nerve-wracking waiting for test results, but it’s incredibly important for your vet to be thorough!
How is Cushing’s disease in dogs treated?
With the right treatment, your furry friend can have a better life and lower the chances of developing other health problems. However, the treatment plan will vary depending on the type of Cushing’s disease your dog has.
Pituitary tumor treatment
If your furry friend is diagnosed with Cushing’s caused by a pituitary gland tumor, your vet may suggest medication instead of surgery if it’s a benign tumor. A common oral medication prescribed for this type of Cushing’s is Vetoryl, also known as trilostane.
Trilostane works by interfering with cortisol production, and one of the benefits of this drug is that you may be able to decrease the medication over time. Other drugs your vet may prescribe to manage Cushing’s disease in dogs include Mitotane (Lysodren), selegiline hydrochloride (Anipryl), or ketoconazole.
Adrenal tumor
Treatment options are available if your dog has Cushing’s disease caused by an adrenal tumor. If it’s a benign tumor, surgically removing the tumor can help cure the disease. However, surgical removal is a complicated procedure that only a board-certified veterinary surgeon should perform.
Another option is a medication called Mitotane, which can help control the amount of cortisol secretion and destroy tumor cells. Your veterinarian may also recommend other medications. Remember, there are options to help your furry friend feel better, but it’s important to work with your vet to find the best treatment plan.
Iatrogenic Cushing’s disease
Iatrogenic Cushing’s disease is treated by discontinuing the steroid medication. Unfortunately, the original disease that was being treated may reoccur.
Additionally, since the steroid medication may have impacted the adrenal glands, your pet may also require hormone replacement therapy to replace the hormones that the adrenal gland normally produces.
The bottom line on Cushing’s disease in dogs
Cushing’s disease in dogs is ruff, I know – but there are ways to manage it.
If your vet has diagnosed your dog and prescribed treatment for Cushing’s disease – monitor your dog’s daily habits as directed by your veterinarian. Follow all prescription instructions, and take your dog in for all follow-up appointments. In most cases, there may be a bit of an adjustment period. Your vet will work with you to “dial in” the right dosage for your pup as the wrong dose can cause side effects.
Also, you may have to increase or decrease drug dosages based on your dog’s lab tests and response to the medication. It usually takes two or three follow-up visits to get it right, and once your dog starts responding to treatment, you may only have to take them in for testing once or twice a year.
If your dog gets a high dose of any of the medications listed above, it can cause Addison’s disease (a condition where the adrenal glands don’t secrete enough hormones). Addison’s disease is basically the opposite of Cushing’s and can be dangerous if left untreated. So, closely monitor your pup’s daily habits and watch for any changes in behavior.
FAQs
What is the best treatment for Cushing’s disease in dogs?
The best treatment for Cushing’s disease in dogs depends on the underlying cause, but options may include medication, surgery, or radiation therapy. Your vet will work with you to develop a personalized treatment plan for your furry friend.
What are the main symptoms of Cushing’s disease in dogs
The main symptoms of Cushing’s disease in dogs include increased thirst and urination, weight gain, increased appetite, panting, thinning skin, hair loss, and lethargy. If you notice any of these symptoms in your furry friend, it’s important to consult with your vet.
How can I treat Cushing’s disease in dogs naturally?
If your furry friend struggles with Cushing’s disease, natural remedies like Melatonin and Lignans may help manage symptoms and promote overall health. While they may not be a complete cure, these supplements can aid in restoring your dog’s system to normal. Always consult your vet to determine the best treatment plan for your furry friend.
What is the main cause of Cushing disease?
The main cause of Cushing’s disease in dogs is usually a pituitary gland or adrenal gland tumor. These tumors cause an overproduction of cortisol leading to health complications if left untreated. Another cause of Cushing’s disease vets see is an excessive amount of steroid medications being given to the dog, which can bring about symptoms but is usually curable by lowering the dose.
- Carotenuto, G., Malerba, E., Dolfini, C., Brugnoli, F., Giannuzzi, P., Semprini, G., Tosolini, P., & Fracassi, F. (2019). Cushing's syndrome-an epidemiological study based on a canine population of 21,281 dogs. Open veterinary journal, 9(1), 27–32. https://doi.org/10.4314/ovj.v9i1.5
- C. (n.d.). Pituitary Gland: What It Is, Function & Anatomy. Cleveland Clinic. https://my.clevelandclinic.org/health/body/21459-pituitary-gland
- Treating Cushing’s Disease in Dogs. (2021, July 8). Treating Cushing’s Disease in Dogs | FDA. https://www.fda.gov/consumers/consumer-updates/treating-cushings-disease-dogs
- ACTH stimulation test Information | Mount Sinai - New York. (n.d.). ACTH Stimulation Test Information | Mount Sinai - New York. https://www.mountsinai.org/health-library/tests/acth-stimulation-test
