Features October 2011 Issue

Properly Diagnosing Addison’s Disease and Your Dog’s Treatment Options

Addison’s disease can mimic many other conditions; here’s how to positively identify it.

Something’s wrong with your dog but you’re not sure what. She seems listless, her eyes have lost their spark, and she just seems “off.” You might notice intermittent muscle weakness, tremors, and an inability to jump into the car or onto a sofa. Or your dog frequently ignores her dinner, vomits, or has diarrhea. These vague symptoms, which may improve and then return, could stem from a dozen canine illnesses – or they might point to Addison’s.

Aiyana, a 3-year-old Italian Greyhound owned by Lydia Kunzler, developed Addison’s last fall, but like many dogs she was initially misdiagnosed. Aiyana is better now, but her medications still require some adjustment.

Addison’s disease, named for the 19th century physician who defined this adrenal gland dysfunction, is also known as hypoadrenocorticism or adrenal insufficiency. While fatal if left untreated, with appropriate treatment Addison’s can be managed so that affected patients lead normal, active lives. First diagnosed in dogs in the 1950s, it is considered an uncommon canine disorder. However, veterinarians who routinely test for Addison’s often find it, suggesting that the illness is not really rare but rather under-diagnosed and under-reported. You don’t find Addison’s unless you look for it. Some veterinarians speculate that Addison’s disease occurs in dogs at a rate as much as 100 times the rate in humans.

Aiyana, a three-year-old Italian Greyhound who lives with Lydia Kunzler in Northern Utah, developed symptoms when she was nine months old, but none of the several veterinarians Kunzler consulted could find the cause.

“Last fall I noticed Aiyana was starting to lose weight,” she says, “and because I had a lot of things going on I attributed her loss of appetite to stress and tried to feed her more. But a week after one of my other dogs passed away she became very sick. She was vomiting, very lethargic, and her digestive system just shut down, sometimes going days without a bowel movement. A few weeks went by, and we had to keep her on intravenous fluids or she’d get really sick again. Finally I decided to change vets. I knew all this vomiting, alternating diarrhea and constipation, and other symptoms weren’t normal.”

Aiyana’s new veterinarian immediately recognized the signs of Addison’s and did an ultrasound test, saw how small the dog’s adrenal glands were, and ordered an adrenal hormone blood test to confirm the diagnosis.

Recognizing Addison’s 

Dogs of any breed, either sex, and any age can develop Addison’s. About 70 percent of dogs with Addison’s are female, although in some breeds, including Standard Poodles and Bearded Collies, males and females are equally affected. The median age of dogs diagnosed with Addison’s disease is 4 to 6 years, but it has been reported in puppies and in dogs as old as 12.

Certain breeds may be predisposed to Addison’s, including Portuguese Water Dogs, Bearded Collies, Standard Poodles, Great Danes, Soft Coated Wheaten Terriers, Airedale Terriers, Basset Hounds, Springer Spaniels, West Highland White Terriers, Leonbergers, Labrador Retrievers, Rottweilers, Saint Bernards, Nova Scotia Duck Tolling Retrievers, Airedale Terriers, German Shepherd Dogs, German Shorthaired Pointers, other Poodles, and mixes of these breeds.

Commonly reported symptoms, which can vary dramatically from dog to dog, include loss of appetite, weight loss, depression, listlessness, vomiting, diarrhea, hind-end pain, muscle weakness, tremors, shivering, increased thirst, excessive urination, a painful or sensitive abdomen, muscle or joint pain, and changes in coat, which may become thicker, thinner, longer, or even curly. About 15 to 20 percent of Addisonian dogs will have dark, tarry stools (melena, caused by gastrointestinal hemorrhage) or blood in their vomit. Symptoms often wax and wane, with the dog getting worse, then better, for months or even years.

Veterinarians examining Addison’s patients may notice mental depression, a thin or emaciated body, muscle weakness, dehydration, patches of darkened skin, a slow and weak pulse, low body temperature, low blood pressure, and pale mucous membranes. Blood tests may show any of the following: elevated potassium, low sodium, elevated BUN and creatinine, elevated liver enzymes, low glucose, high calcium, low protein (albumin and globulin), anemia, low cholesterol, and metabolic acidosis. Urine may be dilute (low specific gravity). A sodium/potassium ratio of less than 27 is strongly indicative of Addison’s, but a normal ratio does not rule it out as many veterinarians assume. A sick dog with normal or elevated lymphocytes and eosinophils (lack of a stress leukogram) can point toward Addison’s.

Addison’s disease, called “The Great Pretender,” is often misdiagnosed because it resembles so many other illnesses. Patients with Addison’s are often erroneously diagnosed as having gastrointestinal diseases such as inflammatory bowel disease (IBD), infections, parasites, cancer of the gastrointestinal tract, or poisoning. Acute renal failure, liver disease, urinary blockage, pancreatitis, insulinoma, hyperparathyroidism, and protein-losing enteropathy are other common misdiagnoses.

The ACTH response test is the definitive test for Addison’s disease. The cortisol level of a dog’s initial blood sample is measured; then the dog is injected with ACTH. An hour later, another blood sample is taken, and the cortisol level measured again. If there is little or no change in the dog’s cortisol levels after the ACTH stimulus, Addison’s is the diagnosis.

The most dramatic Addison’s symptom is the endocrine emergency called Addisonian crisis. This occurs when the dog goes into shock due to circulatory collapse, and it can happen so quickly that a healthy looking dog is suddenly, within a few hours, close to death.

In an Addisonian crisis, the lack of adrenal hormones depletes sodium levels (hyponatremia) and body fluids (hypovolemia), resulting in potassium retention (hyperkalemia), bradycardia (slow heart rate), hypotension (low blood pressure), associated cardiac arrhythmias (abnormal heart beats), and collapse. In other diseases, hypovolemia and shock cause tachycardia (rapid pulse); in Addison’s, the pulse slows. Low blood sugar levels (hypoglycemia) can cause seizures. Vomiting and diarrhea are common.

For many dog owners, the crisis is their first sign that something is wrong. About 30 to 35 percent of dogs with Addison’s are initially diagnosed during a crisis. Patients treated in time with intravenous fluid therapy and glucocorticoid steroids show such rapid improvement that it seems a miracle cure, though some have to be monitored and treated for several days before their condition stabilizes. And the cure is temporary, for without appropriate maintenance care, another crisis will follow.

As many as 90 percent of dogs in adrenal crisis will have elevated creatinine and BUN, which can lead to a misdiagnosis of acute renal failure. Dehydration and low blood pressure cause blood filtration to drop, resulting in “prerenal azotemia,” where waste products build up even though the kidney itself is functioning. Gastrointestinal bleeding can also cause increased BUN. The response to treatment is more dramatic for dogs with Addison’s disease than for those with kidney disease.

Next: Addison’s Anatomy

Comments (7)

Check out group for dogs with Addison's Disease on Facebook--Addison's Disease in Dogs. Great group with experts in low dosing of the medicines. A group on Yahoo too. Check it out. You will be glad you did!

Posted by: Judy J | January 9, 2014 4:07 PM    Report this comment

My 2 yr old Standard Poodle just diagnosed with Addison's. It was so hard to find a diagnosis, we went to our bush property and she went for a wander and would normally only go to the river or hang around with our other standard, she went out onto the highway and luckily we found her and called her back in. Then a very sick dog, no appetite, collapse in hindsight all the classic symptoms of addison's but we thought she must have been bitten by a snake, picked up a poison etc Vet checked for all types of toxin's, she was on a drip for 11 days, testing for everything. Vet noticed she responded really well when he gave her electrolytes or steroids but then fail again the next day. He then tested for Addison's and we had an answer. She is still very weak but on injections & tablets. She was a very active standard - running flat out and loved to swim. Can I expect her to ever get back to full fitness? I am scared to exert her and my other dog is very bored without our daily morning 5km walk or afternoon swims. Can't take one and leave the other behind. How long will it take before she is literately up & running again?

Posted by: Unknown | December 6, 2013 7:27 PM    Report this comment

Hi my four year old female Boerboel has just been diagnosed with Addisons, I was due to have a litter from her next season, could this be harmful now with this condition?

Posted by: Unknown | August 24, 2013 3:12 PM    Report this comment

My mini bull terrier Finn was diagnosed with Addison's around 3 years ago. At first they said he had liver failure. I had already been doing research on my own and his symptoms weren't conducive to liver failure so I took him for a second opinion. My new vet was relentless is finding the diagnosis. Unfortunately shortly after diagnosis, he was bit by a baby copperhead which made getting on track and better twice as hard. Through the unwavering dedication of my vet an myself he was nursed back to health. He takes .9cc of Percorten injections every 25 days. Prednisone barely, more just as needed. This article was great to read. I just recently posted the letter Fiona Apple wrote to her fans when she had to cancel her tour to go home and be with her dog, who was older and about to pass, who also lived with Addison's til 14 years old. Thank you for writing this.

Posted by: Unknown | August 6, 2013 6:46 AM    Report this comment

My Standard Poodle, 1.5 year female, got bit 3 months ago. While at the vet to get stitched up she was given a saditive and that caused a huge reaction, she had diaeriha all over the floor almost immediately. Since than she has never been the same, mostly diaherra or very loose stools. She has been on animal digest, low residual food and flagel twice a day since, not much improvement. She also seems more nervous now. Her energy level is good but has lost 4 lbs in the last month. We haven't done the addisons test yet but I suspect it and suppose we should do it ASAP.

Posted by: Unknown | August 15, 2012 10:03 PM    Report this comment

Thank you for getting the word out on K9 Addison's. The Yahoo K9 Addison's support group was instrumental in helping me manage Duke's (80# Lab-Sheppard X) Addison's. He was diagnosed while in crisis. Fortunately, our Vet had some experience w/ Addison's and confirmed w/ test. He's been on Fludrocortisone (purchased from compounding pharmacy on-line) for 3 yrs now. It took a year to find his "sweet spot". He only gets prednisone (just a quarter tab) in advance of situations like July 4th fireworks because Flud has some prednisone in it naturally. Duke is a picture of health, and cost can be managed. Work with a knowledgeable vet, communicate your concerns with the Addison's support group, and don't be afraid to share your opinion with your Vet and be the voice of your animal. I elected to take the advice of my extremely knowledgeable moderators from Yahoo support group, and had to insist with my vet to move to, in my case a higher dosesage, than what his "book" recommended. But it worked--in Addison's--"it takes what it takes".

Posted by: Unknown | October 27, 2011 9:04 AM    Report this comment

Thank you for a great article on Addison's disease. I received this issue four days too late for my 5-year-old Bichon, Shasta, who I had put to sleep on Tuesday for liver failure. She was one of those pups that always had a medical problem. Reading this article and articles about liver failure put many of her problems into perspective; and, possibly treatable. I wish the vet had put together her recurring bouts of diarrhea, vomiting, and then finally bloody diarrhea in March, and had started looking for a cause. When she got sick last week with a high fever, vomiting, and diarrhea; again, they treated her for the symptoms not for an underlying problem. I definitely will push harder at the vet's office in the future to find a problem early before it reaches a point of no return.

Posted by: Viki N | October 2, 2011 11:47 AM    Report this comment

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