HEALTH ISSUES OF GREATEST CONCERN WITHIN THE BREED

No breed of dog is free of genetic disease, and the Portuguese Water Dog is no exception.  The following list of health issues are those considered of greatest concern within the breed.

CANINE HIP DYSPLASIA

Canine Hip Dysplasia (CHD) is an abnormality of the hip joint, where the head of the thighbone does not fit properly into its pelvic joint socket.  In dogs that have the disease, it is not present at birth but typically develops within the first two years of life.  CHD is progressive and leads to joint inflammation and arthritis.  The condition can cause pain and may be aggravated by strenuous exercise.  CHD is diagnosed by taking a radiographic film (x-ray).

While parents not affected by the disease sometimes produce offspring with CHD, a puppy’s chances of having CHD are greatly reduced when both parents are normal.  All Portuguese Water Dogs used in a breeding program are required to have the proper x-rays taken to diagnose for CHD; these x-rays are then submitted for evaluation to the Orthopedic Foundation for Animals (OFA).  The OFA has developed a standardized method for determining the health of a dog’s hips, which is based on the breed of the dog.  OFA ratings that reflect healthy hips and that are considered acceptable for breeding are Excellent, Good, and Fair.  Ratings considered unacceptable for breeding and that show a dog affected with CHD include Borderline, Mild, Moderate, and Severe. 

The OFA provides a searchable database on their website that lists dogs that have gained an acceptable rating for breeding.  An article on the OFA’s website by Dr. E.A. Corley further explores CHD, and an article by Cheryl Minnier entitled “Canine Hip Dysplasia” is also an excellent resource for understanding the disease.

PROGRESSIVE RETINAL ATROPHY

Progressive Retinal Atrophy (PRA) is a degenerative disease of the retinal visual cells.  Over the course of a dog’s life, visual acuity will start to diminish, first at dusk and, later, during the day.  The disorder typically takes years to progress and leads to complete blindness.  So far researchers of the syndrome have not established the frequency of occurrence, the mechanism, or the age when early diagnosis—using ophthalmoscopy and/or electroretinography (ERG)—is possible.  PRA is usually recognized in dogs 3-5 years of age and older.       

PRA is a recessive disease; a dog may carry the disease in its genes and pass it on to its offspring without being affected by PRA itself.  In the past, the only way of knowing if a dog had PRA was through ophthalmoscopy or ERG testing.  However, in January of 1999, a DNA gene-marker test became available to screen for the disease.  OptiGen, a company that provides DNA based diagnoses as well as information about inherited diseases in purebred dogs, performs the test, which requires a blood sample of the dog.  If a dog is not affected by PRA and is also not a carrier of the disease, then that dog receives an OptiGen rating of “A,” or normal.  In a breeding program, at least one parent in a particular breeding should have an OptiGen DNA test rating of “A.”

STORAGE DISEASE (GM-1)

Storage disease is caused by the lack of a particular enzyme, which allows a build up of toxic substances in the nerve cells to occur.  Storage disease is similar to Tay-Sachs disease, found in humans.  Affected puppies eventually die of the disease; most require euthanasia, generally within the first year of life. 

Storage disease is recessively inherited; both parents must be carriers of the disorder to produce offspring that have Storage disease.  Puppies are tested for the syndrome at 7-8 weeks of age, unless both parents have litter-tested or ancestor-tested as normal (neither affected by the disease nor a carrier of the disease).  Carrier puppies are normal in all aspects and are unaffected by the disease; however, they can pass the disease on to their offspring.  In a breeding program, at least one parent in each breeding should be normal for the disease.  Assessment of Storage disease is DNA based; this test is called GM-1.  The Portuguese Water Dog Club of America, Inc (PWDCA) web site contains more information on this testing procedure.   

JUVENILE DILATED CARDIOMYOPATHY

Juvenile Dilated Cardiomyopathy (JDC) is a disease that affects young dogs.  There is no cure and no treatment for JDC at this time; the disease culminates in the death of the affected dog, which generally occurs between six weeks and seven months of life.  Symptoms of JDC include sudden loss of appetite, decreased energy level, vomiting, and/or difficulty breathing.  Some dogs show no symptoms or physical signs of having the disease; they simply die suddenly.

JDC is a recessively inherited disease.  In order for a puppy to have the disease, both of its parents must be carriers of JDC.  There is no genetic test at this time to help breeders determine if their dogs carry the disease.  Prospective owners can protect themselves against purchasing an affected puppy by asking their breeder if JDC has been produced in the breeder’s program or if it has been produced in the genetic lines that the breeder is working with.  However, since there is no way to test for this disease, there is no way for a prospective owner to be guaranteed that he or she will not receive an affected puppy.