Canine Addisons Disease
Canine Addisons disease, also called hypoadrenocorticism (glandular disorder) is a reduced level or a deficiency of hormones released by the adrenal cortex in the adrenal glands. These hormones are collectively called adrenocortical hormones. This condition is more common in young to middle age dogs. Some dogs like poodles and collies are genetically predisposed to canine addisons. The primary cause is still unknown, but diseases which degenerate adrenal tissues, cancers, injury and overdoses of mitotone are suspected to be the cause of canine Addison’s disease. The Condition is characterized by repeated gastroenteritis (inflammation of the mucous membrane), progressive loss of body condition, anxiety and stress. Vomiting, diarrhea and anorexia are also associated with the condition. Death usually occurs due to circulatory collapse. A treatment plan should be considered a medical emergency; requiring fluid therapy, steroids, mineralocorticoids (hormone that is one of the steroids of the adrenal gland) and glucocorticoids (A steroid hormone produced by the Adrenal Cortex of animals) is the preferable treatment.
Causes of Canine Addisons disease:
The exact cause for canine addisons disease is unknown as of yet; it means that the actual phenomenon; which results into a deficiency of adrenocortical hormones, has not yet been discovered.
- Infections: Any infectious or non infectious disease, which can cause a degeneration and destruction in the tissues of adrenal glands, will likely lead to reduced secretions of cortisol and aldosterone or glucocorticoids (a steroid hormone produced by the Adrenal Cortex of animals) and mineralocorticoids (hormone that is one of the steroids of the Adrenal gland).
- Tumors: Other then diseases, some tumors which are cancerous or metastatic in nature can cause degeneration or suppression of adrenal secretions, despite the fact that the cells of adrenal glands grows in numbers. These tumors actually reduce the capacity of adrenal tissues.
- Injuries: Internal injury or trauma to the adrenal gland causes swelling and thus, loss of function in the end; this causes adrenal failure and results in a deficiency in the hormones.
- Drugs:
In hyperadrenocorticism (glandular disorder) or Cushing’s
disease,
mitotone is used as a primary choice for treatment. Prolonged
therapies of this adrenolytic agent, cause degeneration and suppression
of adrenal tissues; which may be another cause for Canine Addison’s
disease.
Signs & Symptoms of Canine Addisons disease:
Addisons disease in dogs is more common in female adult dogs. It may be due to the unknown phenomenon of immune mediated pathogenesis (disease); which is more hyper (active) in females as compared to male dogs.
Repeated gastroenteritis (inflammation of the stomach or intestines) is one of the most common signs of canine Addison’s disease. Vomiting and diarrhea can also be noted, even during symptomatic treatment; it can recur.
Reduced secretion of aldosterone (a steroid hormone secreted by the Adrenal Cortex); which is the primary mineralocorticoid of the adrenal glands can cause a severe imbalance of minerals in the body; such as potassium, chloride and sodium. As the disease persists, potassium levels in the blood plasma increases; as a result, a slower heart rate and circulatory collapse is expected.
Along with circulatory collapse, renal failure is possible due to mineral problems with mineral re-absorption and excessive water loss Dehydration and weakness are signs; which are associated with renal imbalance.
Some other signs are progressive weight loss and lethargy.
Diagnosis of Canine Addisons disease:
A presumptive diagnosis can be made on the basis of clinical signs and history. Laboratory examination may confirm the diagnosis, confirmed by an elevated level of potassium in the blood serum and slight hypoglycemia (low blood sugar levels).
In the case of Canine Addisons disease an ECG (A graphical recording of the Cardiac cycle) can be helpful in describing an irregular heart rate. The T–Wave will appear elevated, while the P– Wave is will either be flattened or absent. Canine Addison disease dog should be differentiated from gastrointestinal problems, pancreatitis, renal failure or any type of poisoning.
Treatment of Canine Addison’s disease:
Canine Addison’s disease is an adrenal crisis and should be considered as a medical emergency.
Treatment should be initiated with a 0.9% saline infusion, through an IV route immediately after diagnosis. In case of hypoglycemia (reduced glucose level in blood) 5% of dextrose can be added.
Dehydration should be preferably addressed by infusion of the above mentioned solution, 60–70 mL/Kg B.W in 1–2 hours; which is necessary, otherwise an acute circulatory collapse can occur and death may occur after shock. Fluid therapy should be continued until lab abnormalities and dehydration subsides.
In case of shock, take dexamethasone at a dose rate of
2.2–4.4 mg/Kg B.W. Electrolytes, renal function and glucose
levels; should be closely monitored and should be addressed the same as
the fluid therapy, previously described.
Long term maintenance
therapy is required after the initial management, desoxycorticosterone
pivalate should be administered, IM or SC injections for 25–28 days; at
a dose rate of 2.2 mg/KG B.W.
Monitoring of electrolytes, glucose and renal activity must be completed every 2–3 days, during treatment.
Homeopathic natural remedies can be used to help reduce the symptoms of canine addisions. They are safe to use and could provide an added level of support. Adrenal Super-Boost is one product that is specifically made to help dogs that have additions. It contains herbs such as Chamomilla, Zingiber and Lycopus. All three can help the body maintain balance in the endocrine system and temporarily relieve adrenal fatigue. The manufacturer offers additional information and clinical studies that support the use of herbal products for this condition.
After recovery, the dog must be re-examined every 3–6 months
for
recurring signs of Addison’s disease.
References for Addison Disease Dog:
Dobson, J.M, Text Book of Small Animal Medicine (W.B Saunders London. 2001)
