Addison’s Disease


 

What is Addison’s disease (hypoadrenocorticism)?

Addison’s disease results from loss of production of corticosteroids, principally mineralocorticoids (mainly aldosterone) and glucocorticoids (mainly cortisol).

Immune mediated destruction of the adrenal glands is the most common cause of Addison’s disease. This form of disease is classified as primary hypoadrenocorticism and usually results in deficiencies of both glucocorticoids and mineralocorticoids, however cases of isolated glucocorticoid deficiency have been reported (atypical hypoadrenocorticism).

Secondary hypoadrenocorticism (caused by pituitary dysfunction), results in the deficiency of adrenocorticotropic hormone (ACTH). This is a very rare cause of canine hypoadrenocorticism and tends to result in glucocorticoid deficiency only.

How to recognise Addison’s disease

Because Addison’s disease isn’t so easy to identify, being more aware of this condition is half the battle. Addison’s disease is a potentially life-threatening condition.

However as clinical signs associated with the disease are non-specific, can wax and wane, and dogs can respond to non-specific therapy (e.g. intravenous fluids) this condition can be easily mistaken for other diseases (e.g. kidney disease, gastroenteritis including parvovirus infection, neuromuscular and metabolic diseases).

The most common signs of Addison’s disease are:

Almost all cases Common Less common
Clinical History Inappetence Weakness Diarrhoea
Lethargy Vomiting Weight loss
Shivering/muscle stiffness
Polyuria
Polydipsia
Physical examination Depression Dehydration Bradycardia
Weakness Hypothermia