Addison’s disease in dogs is also known as hypoadrenocorticism. Since the symptoms are not always clear, hypofunction of the adrenal glands is often recognized very late. Without treatment, Addison’s disease in dogs is fatal. You can find out everything about Addison’s disease in this article.
Addison’s disease in dogs – what is it?
Addison’s disease is a rare disease of the adrenal cortex in dogs. In most cases, the underfunction of the kidneys occurs together with diabetes (diabetes mellitus).
Addison’s disease occurs in dogs in three forms
- Primary hypoadrenocorticism: most of the adrenal gland is destroyed
- Secondary hypoadrenocorticism: the formation of ACTH is disturbed in the pituitary gland, the adrenal gland produces smaller amounts of glucocorticoids
- Iatrogenic hypoadrenocorticism: when cortisone is administered, the adrenal gland produces less cortisol. If the cortisone is suddenly discontinued, the adrenal glands need time to produce their own cortisol again.
What to do with Addison’s disease in dogs?
If there is a suspicion of Addison’s disease in the dog, special examinations such as an ACTH test should be carried out by a veterinarian. If the suspected diagnosis is confirmed, lifelong therapy is required.
The function of the adrenal glands
Right next to the kidneys are the adrenal glands, which consist of the adrenal cortex and the adrenal medulla. Glucocorticoids, mineralocorticoids and androgens are formed in the adrenal cortex. Dopamine and the stress hormones norepinephrine and adrenaline are produced in the marrow. The adrenal glands use these hormones to regulate blood pressure, the amount of sodium and potassium in the blood, water balance, energy metabolism and fat metabolism.
Addison’s disease affects life expectancy in dogs
If the disease of the adrenal glands is recognized in time, lifelong therapy must be carried out. With the appropriate treatment, the dogs have the same life expectancy as healthy dogs. If Addison’s disease is not treated in dogs, Addisonian crisis occurs. This is deadly.
Which dogs are most affected by Addison’s disease?
Secondary hypoadrenocorticism occurs in dogs of all ages. Female animals between the ages of two months and six years are particularly affected by primary hypoadrenocorticism.
Symptoms & Signs of Addison’s Disease
The symptoms of canine Addison’s disease are not specific. The dog appears tired and is no longer interested or productive. Depressive moods appear. He drinks large amounts of water and thus urinates more, including in the home.
At regular intervals, the four-legged friend suffers from vomiting and diarrhea, which is sometimes bloody. He eats little and is losing weight. The stomach hurts. Touching is avoided. If the mineral balance is disturbed, muscle spasms and cardiac arrhythmias occur. The dog keeps shaking.
The Addison Crisis
Without therapy, there is a complete derailment of the metabolism. The cells are no longer able to perform their normal functions. The internal body temperature drops sharply. The dog is weak and collapses. Blood pressure continues to drop until the heart and circulatory system fail completely. The rapid rise in potassium in the blood throws the heart out of rhythm.
The dog suffers a shock that ends fatally.
How does Addison’s disease develop in dogs?
Addison’s disease in dogs has a variety of causes. Injury, prolonged stress and inflammation of the adrenal glands can all trigger the condition, as can genetic causes. If the adrenal cortex is destroyed, sufficient hormones can no longer be produced. The dog has Addison’s disease.
Cause of Addison’s disease in dogs
The most common cause of Addison’s disease in dogs is an autoimmune disease. The tissue of the adrenal glands is destroyed by antibodies produced by the body. Sufficient hormones can no longer be produced.
A genetic background is also suspected. The disease occurs through inheritance primarily in the following dogs:
- Rottweiler
- Portuguese water dog
- Bearded Collie
- Mastiffs
- Poodle
- Leonberger
- West Highland White Terriers
Tumors, inflammation or injury to the adrenal glands also cause organ destruction and reduced hormone production. When the thyroid gland is underactive or the pituitary gland is atrophied (the pituitary gland becomes smaller), hormone production in the adrenal glands decreases. Under stress, more cortisol is produced. If the stress persists for a long period of time, the adrenal gland begins to stop producing hormones.
Cortisone side effects
Iatrogenic hypoadrenocorticism results from the administration of cortisone. The adrenal gland receives a message from the blood that there is enough cortisol in the bloodstream and stops producing cortisol. If the cortisone is administered over a very long period of time, the adrenal cortex regresses. By suddenly stopping medication that contains cortisone, the dog has less cortisol available. It takes a few days for the adrenal cortex to resume normal production.
Diagnosis – How a vet diagnoses Addison’s disease
Since the symptoms of Addison’s disease in dogs are rather unspecific, it often takes a long time for the veterinarian to make a suspected diagnosis. When measuring the blood pressure, it is noticeable that the values are repeatedly reduced. The blood test shows a clear shift in the electrolytes and the solid components of the blood. The ACTH level in the blood may be low. When examining the morning urine, it is noticeable that the specific gravity of the urine is reduced.
The ACTH stimulation test
First, the cortisol level is determined via a blood test. The vet gives the dog an injection of ACTH. After an hour, another blood sample is taken. If the cortisol level has risen, there is no disease of the adrenal glands. If the cortisol level remains constant, the dog is probably suffering from Addison’s disease.
X-ray and ultrasound
An x-ray shows enlarged adrenal glands caused by tumors. The ultrasound scan can show reduced adrenal glands with severely narrowed blood vessels. Existing changes in the lungs and heart can also be detected with these examinations.
What medications for Addison’s disease in dogs?
In canine Addison’s disease, the mineralocorticoids and glucocorticoids must be replaced. This substitution therapy is carried out by administering prednisolone and fludrocortisone.
Therapy and treatment options for the disease
A dog suffering from Addison’s disease must receive therapy for life because the disease cannot be cured. However, experience has shown that dogs treated with mineralocorticoids and glucocorticoids have the same good quality of life as healthy dogs.
Treatment of an Addisonian Crisis
If Addison’s crisis has already occurred, the dog is given an IV of sodium chloride to balance electrolytes and support cardiac activity. Mineralic corticoids and glucocorticoids compensate for the missing hormones of the adrenal cortex. The excess of potassium is reduced by an infusion of calcium gluconate. In the case of an Addisonian crisis, a veterinarian must always be consulted immediately, since the dog’s life is in danger. It is an emergency that should be announced by telephone before driving to the clinic.
Treatment of chronic Addison’s disease in dogs
The missing glucocorticoids and mineralocorticoids must be replaced for life. Fludrocortisone and prednisolone are given daily. The correct dosage is determined by regular blood tests. Stress from travel, dog shows, extreme dog sports or stressful exams at dog school should always be avoided so that the clinical picture does not worsen.
Prophylaxis and prevention – that can be done
There is no way to prevent Addison’s disease. Early diagnosis can prevent Addisonian crisis from occurring. If the disease is treated in the early stages, the quality of life and life expectancy of the dog are not changed.
Sufficient exercise, healthy and high-quality dog food, avoiding obesity and stress reduce the risk of the dog suffering from Addison’s disease. If a dog suffers from regular diarrhea, an ACH stimulation test should always be carried out as well.
For some diseases it is necessary to give the dog cortisone. The dosage set by the veterinarian should always be followed exactly. After the end of the therapy, the cortisone must be slowly tapered off. This means that the dosage is reduced every day. This enables the adrenal cortex to resume its own cortisol production.
