By: Dr. Fiona Caldwell
Idaho Veterinary Hospital
For Pets Best Insurance
Charlie hadn’t eaten in three days. He was weak, seemed wobbly and had been excessively urinating. He was only a year old, and had always been a great eater. Although Charlie didn’t have pet insurance, when his owners became concerned, they brought him to see me. He is a beautiful white spotted cattle dog mix, and I could tell in the exam room that he didn’t feel well.
His physical exam revealed only weakness and lethargy, so a screening blood test and urinalysis were performed. While the physical exam was unremarkable, the diagnostic tests were very abnormal. The bad news was that Charlie was Addisonian; the good news is that his disease, while it can be fatal, is treatable.
Typical Addison’s disease, or hypoadrenocorticism is an inability of the body to produce steroids (cortisol) and mineralocorticoids. It is caused by immune-mediated destruction of the adrenal cortex, part of the adrenal glands. Your body is continuously adjusting your levels of cortisol, increasing levels during times of stress in order to keep you healthy. Mineralocorticoids are responsible to ensuring your electrolytes are in balance. Without them your kidneys cannot retain water, causing dehydration, and electrolytes can become dangerously imbalanced.
There is an Atypical form of Addison’s disease where there is a lack of cortisol only, and not mineralocorticoids. These dogs will have normal electrolytes on blood work and can be very difficult to diagnose.
Charlie had dangerously high potassium. Levels too high can be cardiotoxic, causing heart rhythm abnormalities. He was dehydrated, but he still had diluted urine since his kidneys were inappropriately wasting water. He was admitted to the hospital for overnight care to correct his electrolyte imbalance and to administer steroids and mineralocorticoids. Pet health insurance would have been helpful in Charlie’s case!
Diagnosis of this disease, while suggestive on routine screening blood work, is done by a test called an ACTH test. This test measures the body’s ability to produce steroids in response to a hormone normally produced in the pituitary gland. A synthetic version of this hormone is administered intravenously and a normal dog will respond by producing cortisol, which is subsequently measured. A dog with typical and atypical Addison’s disease will not produce any cortisol in response. Cortisol insufficiency can result in a decrease in the production of glucose used for energy and tolerance to stress is diminished.
Typical clinical signs of this disease can be varied from just lethargy and anorexia, like Charlie’s case, to vomiting, diarrhea, anemia, collapse and even shock. Intensive hospitalization and aggressive treatment is always warranted in the acute phase of an “Addisonian crisis.”
After the ‘crisis’ has been treated, medication for this disease is given long term, for the life of the pet. Most pets with Addison’s disease need to take daily prednisone and have monthly injections of a mineralocorticoid to keep their electrolytes balanced. Generally they need a little extra TLC too, as everyday ‘stressful’ things, such as family coming to visit, vacations, or kenneling can be hard for their bodies to adjust to. With some extra diligence though, most pets can live a long healthy life when well controlled. Always consider dog insurance to help defray unforeseen costs of pet care.