Infographic: Your Guide to Cushing’s in Pets
What is Cushing’s Disease?
Cushing’s Disease is caused when your pet overproduces steroids. Common causes include the formation of a small tumor in the brain’s pituitary gland, or an adrenal gland tumor in the adrenal gland (produces steroids).
Signs of Cushing's syndrome in dogs
Your pet will show increased panting, increased urinating and drinking, have a “pot-bellied” appearance, thin skin, increased appetite, anxiety, hair loss, and more frequent skin infections.
Remember! These signs can also be seen with other diseases, so book an appointment with your vet to do proper testing to diagnose your pet.
Diagnosis
Based on signs and changes of your pet’s routine examination, such as high liver values and protein in the urine, your vet may want to test for Cushing’s.
2 tests for Cushing’s Disease
ACTH stimulation test: takes 2 hours
Low dose dexamethasone suppression test (LDDST): takes 8 hours
Other tests include blood pressure measurement, urine cultures, urine protein: creatinine ratio, a head CT scan and/or an abdominal ultrasound (to detect an adrenal tumor).
Complications
In rare cases, the pituitary tumor can cause seizures and other behavioural abnormalities. Adrenal tumors are usually benign, but can be cancerous and spread to other organs.
Other complications include high blood pressure, strokes, increased urinary tract and skin infections, calcinosis cutis (deposition of calcium in the skin), skin-color changes, lung clots, and muscle and hair loss.
How to treat Cushing’s Disease
Treatment depends on the cause. If the cause is …
An Adrenal Tumour: Surgery to remove the affected gland is usually the best option. Since this is a major surgery, it is advised that a board-certified surgeon with 24-hour post-operative care perform this surgery.
A Pituitary Tumor or surgery is not an option: There are 2 possible medications – Lysodren (also known as mitotane) & Trilostane (also known as Vetoryl).
Lysodren destroys the adrenal gland, so your pet must be monitored closely to prevent too much of the adrenal gland to die off. During the induction phase, your pet will receive high doses of the medication once to twice daily for around 5-10 days. If your pet has vomiting or diarrhoea, or you are worried for other reasons, call your vet. If the disease is controlled, your pet will enter a maintenance period with medication 1-4 times per week at lower doses.
Trilostane inhibits cortisol production. It has less potential for side effects and is safer, but can inhibit a too little production of cortisol which is not as effective. It is given twice daily.
With both medications, your vet will perform periodic ACTH stimulation tests, blood pressure tests and blood work to monitor your pet’s response to therapy.
Treatment Complications: If the adrenal gland is too severely affected (by surgery or medication), your pet may become Addisonian - not producing enough steroids. This can be life-threatening, and potentially permanent, so your pet will need to be treated with steroids to see whether the adrenal glands will get back to normal.
Prognosis
Most pets with Cushing’s Disease will have a normal life span if they are treated appropriately. Since Cushing’s is a lifelong condition, I recommend that pet owners maintain good contact with their vet. I always strive to work alongside pet owners to support them and educate them through the treatment process to ensure the well-being of their pets.