The adrenal gland is a small gland near the canine kidney. This gland produces steroid hormones such as glucocorticoids and mineralocorticoids that help the dog maintain a healthy metabolism. When the adrenal gland is injured or infected, it may not produce these hormones. The dog becomes very sick and could die without urgent care. This rare condition is called Addison's disease or hypoadrenocorticism. The disease is treatable, and medicated dogs can live a normal, enjoyable life.
Addison's disease or hypoadrenocorticism can affect any dog. It is diagnosed more often in young to middle-aged dogs, generally 4 to 5 years old. About 70 per cent of the dogs diagnosed are female. About 30 per cent are mixed breeds. The disease is genetically more common in standard poodles, Great Danes, Portuguese water dogs, German shepherds, West Highland terriers and rottweilers. Addison's may also be triggered by adrenal gland diseases, infections and steroid medications.
Many symptoms are similar to other diseases, and the dog may not seem seriously ill. When the symptoms come and go, your dog may seem to be out of sorts but not really sick. Some days the dog may be quieter than usual and the next day back to normal. Mild symptoms include listless or lazy behaviour, lack of appetite and muscle weakness.
Addison's disease progresses to other symptoms that are more noticeable, such as vomiting right after a meal. Excessive thirst, frequent urination and diarrhoea are typical of other diseases but can indicate Addison's disease, as the missing hormones trigger gastrointestinal distress. Muscle tremors and sudden hindquarter weakness are apparent.
When the disease progresses to a critical stage, the dog may suddenly collapse, go into shock and be near death. This acute attack is called Addison or Addisonian crisis and requires emergency veterinary care and intravenous fluid therapy for survival and recovery. More than 30 per cent of diagnoses of hypoadrenocorticism are due to this attack, in dogs that have not shown signs of serious illness until the crisis occurs.
A veterinarian uses several tests to diagnose Addison's disease because other diseases can have the same symptoms. A blood test measuring adrenal gland response is usually the final step in confirming this uncommon disease. Treatment depends on the disease progression and your dog. Medications may include injections, prednisone tablets and other prescription drugs for hormone replacement. Your dog will be tested periodically to find the right combination of drugs and dosages.