Cushing’s disease is not a known hereditary condition of Bedlington Terriers. But a number have been diagnosed. It occurs in middle aged and older dogs.
Cushing’s disease occurs when there is a build-up of cortisol (steroids) in the blood. Occasionally this can be iatrogenic (due to treatment with steroids), this should resolve when the treatment is stopped. Usually it is due to excess steroids being produced by the adrenal glands. The underlying cause in 85% of cases is a microscopic, usually benign, tumour in the pituitary gland (under the brain) stimulating the adrenal glands excessively. In the remaining 15% of cases it is related to an abnormality of the adrenal glands, often a tumour, which is sometimes cancerous.
The most common sign of Cushing’s is a severe increase in thirst and urination. There are many other reasons why this may occur. Other signs, which may or may not be present include a poor coat (thin and pale), thin skin, a pot-bellied appearance, weakness, loss of muscle, panting excessively. As the signs come on gradually in most cases it may be mistaken for old age.
A urine test and general blood tests usually show changes which would make the vet suspicious of Cushing’s and help to rule out other causes. Commonly the liver parameters are increased so it is important to differentiate whether Cushing’s is the cause of that rather than liver disease, including copper toxicosis. To do this either an ACTH Simulation Test or a Low Dose Dexamethasone Suppression Test are usually performed. Both tests have advantages and disadvantages a vet may prefer one test or the other.
If a diagnosis is obtained treatment (which is generally safe as long as regular monitoring is done to make sure the dose of treatment is neither too high or too low) can be given unless the dog has other health issues which would be adversely affected. Generally, a cure cannot be obtained and ongoing medication is necessary, but many dogs will live happily for a number of years on treatment. Often the excessive drinking and urination will improve within 2 weeks, the other signs can take longer.