Cushing's disease can cause serious symptoms and complications, and even threaten your pooch's longevity. Our Orlando vets explain the condition and its causes, as well as potential treatments for Cushing's disease in dogs.
Causes of Cushing's Disease in Dogs
If your dog's body has an excessive concentration of cortisone, the culprit could be a tumor in your dog's pituitary gland.
This can cause pituitary-dependent Cushing's diseases (also known as hyperadrenocorticism), a clinical condition that can put your dog at risk for a variety of serious conditions and illnesses, from diabetes to kidney damage.
Symptoms & Complications of Cushing's Disease in Dogs
The most common signs of Cushing's disease in dogs include:
- Increased appetire
- Hair loss
- Thick skin
- Muscle weakness
- Excesssive thirst or drinking
While a dog with Cushing's disease will display at least one of these symptoms, it's uncommon for a pooch to display all of them. Since the signs are vague, we strongly recommend visiting your veterinarian right away if you notice any of them.
Dogs with Cushing's disease have an increased risk of kidney damage, high blood pressure and blood clots.
Diagnosing Cushing's Disease in Dogs
Our veterinarians at East Orlando Animal Hospital are trained to diagnose and treat several internal diseases and conditions. The diagnostic imaging tools and treatment methods in our vet lab allow us to effectively identify and manage these issues.
Your veterinarian will need to perform a physical exam and take blood tests to diagnose Cushing's disease. Tests might include but are not limited to a full chemistry panel, complete blood panel, urine culture, urinalysis and adrenal function tests (low-dose and high-dose dexamethasone suppression test, and potentially ACTH stimulation test). Keep in mind that adrenal function tests may result in false positives when similar clinical signs of another disease are present.
While ultrasound can help to diagnose Cushing's disease, it's more useful to help identify other conditions that might be causing the symptoms you've noticed in your dog. Other diseases that may cause similar symptoms include tumors in the spleen or liver, chronic inflammatory liver disease, bladder stones, gallbladder disease and gastrointestinal disease.
The results of an ultrasound can be influenced by patient movement or interference due to gas in the overlying intestine, which means we may not be able to detect enlargement with an ultrasound. Most vets prefer an MRI (magnetic resonance imaging) - an effective but expensive diagnostic imaging procedure - to check your dog's adrenal glands.
Treatments & Medication for Cushing’s Disease in Dogs
Currently, two main drugs can treat Cushing’s disease in dogs. Treatment options include a form of the insecticide DDT (drug names include Lysodren® and mitotane) can destroy the cells that produce cortisone in the adrenal glands.
Other medication such as trilostane help decreases the amount of cortisone that the adrenal glands produce. This accomplishes this goal by inhibiting specific steps in the cortisone production process. Both trilostane and mitotane can effectively treat and control the signs of Cushing’s disease.
When it comes to discussing how to treat Cushing's disease in dogs with your vet, follow their instructions diligently and ask questions if necessary.
After the induction phase with mitotane, you will need to bring your dog to our clinic for an ACTH stimulation test, which “stimulates” the adrenal gland. This test can be done on an outpatient basis to help your vet determine the starting point for a mitotane maintenance dose. If the mitotane is working, the adrenal gland will not overreact to the stimulation.
Though you won’t need an induction phase for trilostane, dogs often require small adjustments to trilostane doses early in treatment. Over their lifetime, routine monitoring of blood tests may indicate that other adjustments need to be made. How well clinical symptoms of Cushing’s disease can be controlled can also mean changes are required.
No matter the medication, your dog will likely be on it for the long term, and may require periodic adjustments in doses. He or she will need to come in for ACTH stimulation tests as often as monthly until we can control the excessive production of cortisone. Regular testing will be needed.
If we discover that your pet requires a procedure or expertise that we do not offer, we can refer you to an experienced internal medicine specialist.
Adverse Reactions & Prognosis
With diligent observation and long-term management, the symptoms of the disease can be minimized. When provided in the proper dosage, medication for this condition can prove very effective in treating Cushing's disease in dogs. However, the wrong dose can cause mild or severe side effects.
With blood test monitoring, it’s unusual for adverse reactions to appear. But if they do, they may include:
- Lethargy, depression or weakness
- Gastrointestinal (stomach) upset - diarrhea or vomiting
- Picky eating, eating slowly (taking longer than normal to eat or leaving food), or decreased appetite
If you notice any of these symptoms, discontinue the medication and call your veterinarian right away.
While medication costs and the need for frequent blood monitoring can make Cushing’s disease expensive to manage, diligent followup care and monitoring for adrenal function can make for a good prognosis.
Pets who do not receive adequate monitoring and follow-up often experience relapses and severe illness or death, as a result of complications.
Note: The advice provided in this post is intended for informational purposes and does not constitute medical advice regarding pets. For an accurate diagnosis of your pet's condition, please make an appointment with your vet.