Cushing’s syndrome is caused by the overproduction of adrenal gland hormones, especially of cortisol. It may be the result of long-term glucocorticoid or cortisol medication, or the overproductin of the body’s own cortisol. The reason for overproduction of cortisol can be a tumour in the pituitary gland or in adrenal gland or a functional disorder of these organs.
The disease is rare in cats but common in dogs. Middle-aged or old dogs are usually affected, and often small breeds have Cushing’s: Maltese dogs, poodles, Dachshunds and Boston Terriers. In larger breeds, e.g. Boxers, the reason often is a tumour in the adrenal gland.
Typical symptoms are increased drinking and urinating, rise in appetite, weight gain, depression and muscle weakness. The patient may also be less resilient to heat, it may pant and have behavioural problems.
There are also skin symptoms related to the disease, such as thin skin, blackheads and darkening of the skin. The animal may also have symmetrical bald skin areas e.g. on its sides.
Cushing’s disease is treated with medicine, surgery or both. The medicine, mitotane, destroys the adrenal gland cells and decreases the secretion of the hormones. The treatment is lifelong. You must wear gloves while handling the medicine.
If the medication causes side effects (loss of appetite, vomiting, diarrhoea, fatigue etc.) divide the dose into 2-4 smaller doses and mix the medicine with food. If the symptoms continue, contact the vet.
If there are side effects, contact Your vet.
The vet will take a control sample after 1,5 months, and then every 3-6 months.
The prognosis for patients on mitotane is uncertain. Some of the patient (approx. 25 %) must discontinue the medication due to side effects. With the treatment, some patients live 3-5 years.
The first symptom to disappear is increased drinking (within 2 weeks). Skin symptoms and baldness take the longest to heal (approx. 3-5 months).