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The 411 on PWDs
September 1, 2005
By
Michelle Gerhard Jasny, VMD
Franny is a 3-year-old Portuguese Water Dog (PWD) whose family has always loved the breed. How could you not love dogs that, in the old days in Portugal, were actually taught to herd fish into nets, retrieve lost tackle, and act as ship-to-ship couriers? Also known as Portuguese Fishing Dogs, their compact size was practical for small fishing vessels. Although their use as working dogs diminished as the nature of the coastal fishing industry changed, the breed was saved from disappearing by a wealthy Portuguese shipping magnate and dog fancier. The first pair came to the United States in 1958 and in1972 the Portuguese Water Dog Club of America was founded. At that time there were only 12 PWDs in the United States. As more and more people have come to appreciate their spirited but obedient disposition, and their luxurious non-allergenic, non-shedding coat, PWDs have steadily increased in popularity. They were accepted for AKC registration in 1983.
Franny’s Island family got their first PWD in 1989. A lovely dog, at the age of six, he collapsed with an acute case of an uncommon adrenal gland disorder called Addison’s disease. (Us old folks will remember that J.F.K. had this disease.) He pulled through the crisis, but several months later he developed an abdominal mass and we lost him. Soon after, the family tried again. Another beautiful dog, their second PWD succumbed to lymphosarcoma at the tender age of five. Undaunted, they tried again. Maybe third time would be the charm. Franny arrived in 2002.
This spring, Franny started to have intermittent diarrhea. This isn’t uncommon in young, high-energy dogs, and I wasn’t worried. Maybe she was getting into the garbage or the compost? PWDs are notorious for “dietary indiscretion.” One Animal Poison Control specialist commented that, considering how few PWDs there are in the United States, they seem to be over-represented in calls to the Toxicology Hotline, the callers often beginning with the comment “Guess what he ate this time.” But Franny’s owners assured me she was closely supervised. I advised routine symptomatic care — bland diet, Pepto-Bismol, and ruling our intestinal parasites. They spoke with her breeder who said that several littermates had wheat and corn allergies. We put her on wheat-free, corn-free food. She seemed to improve.
One month later, Franny suddenly lost her appetite and was up all night restless and whining. She was seen by the emergency veterinarian on call. Nothing abnormal was found except a tender tummy. More gastroenteritis medication. More bland diet. Two days later, she was increasingly lethargic and still not eating. Time for tests. X-rays were normal but blood work showed a number of abnormalities, the most dramatic being a marked elevation in her bilirubin levels, an indication there might be a problem in her liver or gall bladder. Franny was admitted to the clinic for intravenous fluid therapy. Again, she seemed to improve and was sent home with oral medication. Two days later, Franny came back again. She was in better spirits but still not eating.
On physical examination, everything looked shipshape. I got a jar of chicken baby food. Franny lapped up half eagerly. Then stopped. Although this was encouraging, half a jar of baby food ain’t much of a meal for a 50-pound dog who hasn’t eaten in six days. “Let’s check the blood work again,” I suggested, for lack of a better idea. After drawing blood I sent them home. “It’s probably just taking her a while to bounce back,” I stammered. “Go buy some baby food and call me later.” I wasn’t expecting anything dramatic in her labs, and the rest of the afternoon zipped by in a rush of animals, paperwork, and telephone calls. At the end of the day, I checked my inbox. Oh, here’s Franny’s blood work. Oh, bilirubin levels are fine now . . . but, Oh! Look at her electrolytes! Her potassium was high. Her sodium and chloride low. Just like their first PWD many years ago, Franny has Addison’s disease.
"The Great Pretender"
Technically known as hypoadrenocorticism, Addison’s disease is a malfunction of the adrenal glands that leads to inadequate production of hormones necessary for maintaining proper electrolyte balance in the body (mineralocortocoids like aldosterone) and hormones that maintain homeostasis in response to stress (glucocorticoids like cortisol.) Addison’s occurs in about one in 3,000 dogs, usually affecting young to middle-aged, female dogs, although males are also susceptible, especially in standard poodles and bearded collies. Breeds known to be predisposed include Great Danes, poodles, West Highland white terriers, Leonbergers, Nova Scotia duck tolling retrievers, bearded collies, and PWDs. It can occur in an acute form, like it did with the family’s first PWD who collapsed suddenly one night, or a chronic form, like Franny.
Chronic Addison’s has been given the name “the great pretender” as it can be easily confused with many different diseases. Difficult to diagnose, especially in the early stages, nonspecific signs such as poor appetite, vomiting, and diarrhea, wax and wane. Other symptoms may include excessive drinking, excessive urination, blood in stools, slow heart rate, and shivering. I remember one dog I saw years ago. The only sign was that the owner insisted the dog trembled when stressed. I thought it was just a case of owner anxiety, but agreed to run basic tests to reassure the mom. Mother Knows Best. Sure enough, the dog had Addison’s. A potassium/sodium imbalance is the first clue in most cases. This imbalance can be caused by other illnesses, but is a good indication to run an ACTH stimulation test to get a definitive diagnosis. Simply put, what we do is check Franny’s baseline cortisol level, then give a hormone injection that should stimulate the adrenal glands to produce more cortisol. After an hour, we draw a second sample. A normal dog will show a nice rise in cortisol levels. A dog with Addison’s disease will have little if any change.
Addison’s disease can be treated with daily oral medication or monthly injections to control electrolyte levels. Oral corticosteroids are also needed in many cases. Once the disease is under control, Franny has a normal life expectancy but, if not treated, Addisonians can go into acute crisis, which requires immediate and aggressive intervention and may be fatal. Considering how uncommon this disease is, was it just incredible bad luck for one family to have two dogs with the same condition? Well, that breed we love so dearly has an inherited predisposition to Addison’s. Instead of the overall average of one in three thousand, PWDs get Addisons at a rate of about one in a hundred. The PWD Club is documenting cases and researching about how Addison’s is passed on, so hopefully, by careful breeding, the rate of such serious inheritable problems can be reduced. In the meantime, Franny is well on her way to stabilizing and we wish her a long, happy life.
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