Addison’s disease, also known as hypoadrenocorticism, is a hormonal disorder in dogs resulting from the adrenal glands’ insufficient production of cortisol and aldosterone. These two small glands, located adjacent to the kidneys, play crucial roles in regulating various bodily functions. Cortisol assists dogs in managing stress, while aldosterone is vital for maintaining the body’s water and electrolyte balance. A deficiency in these hormones leads to hypoadrenocorticism.
There are two primary forms of Addison’s disease: primary and secondary. Primary Addison’s disease is more common and can be further categorized into typical and atypical forms. In the primary type, the dog’s own immune system attacks and destroys the adrenal glands, a process known as idiopathic destruction. Less frequently, medications, toxins, cancer, or other concurrent diseases can cause primary hypoadrenocorticism. Additionally, the medication used to treat Cushing’s syndrome can sometimes damage too much adrenal tissue, leading to a deficiency in cortisol and aldosterone.
Secondary Addison’s disease stems from issues with the pituitary gland, a critical hormonal regulator in the brain, often due to a tumor. It can also develop if a dog has been on long-term steroid treatment and the medication is suddenly discontinued.
Symptoms of Addison’s Disease
The symptoms of Addison’s disease in dogs can be varied and may include lethargy, weakness, poor appetite, vomiting, weight loss, depression, dehydration, diarrhea, and excessive thirst. Dogs may also feel cool to the touch, exhibit shaking, and have a slow heart rate. In severe cases, a dog may experience an Addisonian crisis.
Recognizing an Addisonian Crisis
An Addisonian crisis is a life-threatening emergency. If your dog suddenly displays extreme weakness, severe vomiting and diarrhea, or collapses, contact your veterinarian immediately. This sudden downturn often indicates a critical drop in hormone levels.
Diagnosing Addison’s Disease
When you suspect your dog might have Addison’s disease, your veterinarian will conduct a thorough physical examination and gather detailed information about your dog’s history. Given that the symptoms can overlap with many other conditions, diagnostic tests are crucial to pinpoint the cause.
These tests may include:
- Chemistry tests: To assess kidney, liver, and pancreatic function, as well as blood sugar levels.
- Antibody tests: To check for exposure to vector-borne or other infectious diseases.
- Complete Blood Count (CBC): To rule out blood-related disorders.
- Electrolyte tests: To determine if your dog is dehydrated or experiencing an electrolyte imbalance.
- Urine tests: To screen for urinary tract infections, other diseases, and evaluate the kidney’s concentrating ability.
- Thyroid test: To check if the thyroid gland is producing adequate thyroid hormone.
- ECG: To screen for abnormal heart rhythms that could indicate underlying heart disease.
- ACTH-stimulation test: This is a key test to evaluate cortisol levels in the blood and confirm the diagnosis of Addison’s disease.
Treating Addison’s Disease
Fortunately, dogs diagnosed with Addison’s disease can often be successfully treated with oral medication. With proper treatment, many dogs can maintain their normal diet and activity levels, leading a full life, even after experiencing an Addisonian crisis.
Your veterinarian will closely monitor your dog’s progress, especially during the initial phase of treatment. This may involve short periods of hospitalization for observation and follow-up testing to ensure the medication is effective and well-tolerated.
Dogs with Addison’s disease typically require lifelong hormone replacement therapy for both cortisol and aldosterone. During stressful events, such as boarding, traveling, or undergoing surgery, dosages of certain medications, like cortisol, may need to be temporarily increased. Regular veterinary check-ups are essential to ensure your dog remains stable and responds well to her medication. Your veterinarian will make any necessary adjustments based on follow-up blood and urine tests.
The prognosis for dogs diagnosed with Addison’s disease is generally good to excellent once a diagnosis is confirmed and they are on a stabilizing medication regimen.
If you have any questions or concerns regarding your dog’s health, always consult your veterinarian. They are your most reliable resource for ensuring the well-being of your beloved pet.
