Termed medically as hypoadrenocorticism, Addison's disease refers to a malfunction within the adrenal glands, most commonly observed in dogs. Afflicted animals lack the production of essential hormones necessary for optimal bodily operations, making this condition potentially fatal if overlooked. Dive into our curated articles on Addison's disease to gain a deeper insight.
How Veterinarians Diagnose Addison's Disease in Dogs
Veterinarians employ various methods to pinpoint Addison's disease in dogs. Key steps include:
- Obtaining a detailed medical history.
- Conducting a comprehensive physical assessment.
- Performing complete blood tests.
- Utilizing the ACTH stimulation blood test, which primarily evaluates cortisol deficiency.
If a dog significantly improves after receiving treatments like intravenous fluids and steroids for shock, the veterinarian might consider Addison's disease the potential root cause.
Complete blood tests often showcase high potassium and reduced sodium concentrations. However, these electrolyte imbalances might not be evident in the case of atypical Addison's disease. Occasionally, high kidney enzyme levels (azotemia) might impersonate kidney ailments. In rarer cases, blood sugar levels might be diminished, resembling a pancreatic tumor known as insulinoma.
The cornerstone diagnostic test for Addison's disease is the ACTH test. A blood sample is drawn to ascertain cortisol concentration (a stress hormone). Subsequently, an intravenous ACTH dose is administered – ACTH being the brain hormone that triggers corticosteroid release during stressful situations.
Another blood sample is obtained an hour post-administration to evaluate the dog's ACTH response. A diagnosis of Addison's disease is considered when the baseline cortisol is found low and there's a negligible reaction to the administered stress hormone.
In urgent scenarios, baseline cortisol levels might be analyzed. If found low, a comprehensive ACTH stimulation test could be scheduled once the dog regains stability. At times, an abdominal ultrasound might be carried out to detect undersized adrenal glands.
Additional diagnostic tests might include the urine cortisol-to-creatinine ratio, inherent plasma ACTH concentrations, and plasma renin levels, concentrating on the canine's plasma metrics—generally, patients without Addison's disease typically display a typical ACTH stimulation test outcome.
It's worth noting that some breeds, especially those originating from the Pacific Rim, like Shiba Inus and Akitas, often present with elevated potassium levels in their blood tests. Also, it's essential to be aware that whipworm infections can artificially elevate potassium and reduce sodium concentrations, potentially leading to misinterpretations during the diagnosis of Addison's disease.
Treatment for Addison's Disease in Dogs
During an Addisonian crisis, treatment primarily focuses on robust intravenous fluid administration and injectable steroids. Addressing low blood sugar (hypoglycemia) and rectifying irregular heartbeats may also be crucial. Most affected canines show a swift positive response and often achieve full recovery.
Replenishing mineralocorticoids, such as aldosterone, a steroid hormone, is central to treating Addison's disease. This can be achieved through oral fludrocortisone, taken twice daily, or by injecting DOCP (desoxycorticosterone pivalate) every 25-30 days. Your veterinarian will guide you toward the best treatment course tailored to your dog's needs.
Dogs given fludrocortisone benefit from both its glucocorticoid and mineralocorticoid properties. On the other hand, canines on the DOCP injection will need supplemental glucocorticoids (like oral prednisone) as DOCP exclusively offers mineralocorticoid benefits.
While some experts lean towards DOCP for its superior electrolyte management compared to oral fludrocortisone, the choice often hinges on individual vet preferences and the dog's needs. For instance, some canines may react negatively to injections, while others could resist oral medications. Your veterinarian will suggest the optimal treatment method based on your dog's diagnosis.
After therapy initiation, periodic checks are typically scheduled, including electrolyte blood tests and ACTH stimulation tests. These checks are often set for days 10, 30, and 90. Adjustments in the mineralocorticoid medication are made once the electrolyte balances stabilize. To maintain this balance, periodic checks are conducted a few times annually.
During times of heightened stress, it might be necessary to augment the glucocorticoid dosage. Situations like vet appointments, journeys, owners traveling, or other potentially stressful events can amplify stress in Addisonian canines. Temporarily upping the steroid dosage can help in averting symptoms such as fatigue, vomiting, diarrhea, and, most importantly, an Addisonian crisis.