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Health of the Breed

This stunning and unique breed is steeped in history and it should be no surprise that breeders and owners are passionate about their health and breeding for the future.

We hope to inform, direct and link to sites that may help you with any health problems you wish to explore or that we have found within the breed. It should be noted that compared to other breeds the PWD is healthy and with ongoing care of breeding it should remain that way.


Alongside the wealth of information our committee members hold, a new post has been introduced from the Kennel Club of a Health Co-ordinator.


Find out more about the role here or contact our Health Co-ordinator, Wendy Smith, via email

Health Testing

  • Gangliosidosis GM1
    GM1-Gangliosidosis (GM1) in the Portuguese Water Dog (PWD) is an inherited storage disorder that causes a fatal disease in puppies. Research conducted by Wang et al. (J. Inherit. Metab. Dis. 23, 2000; 593-606) identified the GM1 causal mutation and DNA testing had been provided by the research group at New York University until mid-2013. In July 2013, an exclusive license of the patented GM1 was transferred to OptiGen where the test is now available. ​ PWD puppies affected with GM1-Gangliosidosis develop nervous system manifestations including ataxia, seizures and changes in temperament. Dogs affected with GM1-Gangliosidosis rarely survive beyond 6 months of age. To avoid producing GM1-affected puppies, breeders are encouraged to test their dogs before they are bred, and to refrain from breeding two carriers to each other. The table below highlights in yellow the breedings that will NOT produce GM1-affected pups. These breedings include at least one parent proven "Normal/Clear" by the OptiGen GM1 test. All other combinations are at risk of producing affected pups.
  • Hips and Elbows
    What is hip dysplasia? Hip dysplasia is a condition where the hip joint does not develop correctly. As the dog gets older, the joint undergoes wear and tear and the joint deteriorates, leading to a loss of function. This can cause varying degrees of pain, discomfort, stiffness and lameness. How is hip dysplasia inherited? Hip dysplasia is a complex inherited disorder, which is influenced by a number of different genes and by several environmental factors (e.g. diet, exercise or factors when in the womb before birth etc.). Each of the genes that help to make a dog’s hips may have different possible versions. Some versions increase the risk of hip dysplasia, while others decrease the risk. Each dog will have a mix of these “good” and “bad” versions of genes, making it very difficult to predict to what extent a dog will be affected. The impact one version of a gene has might only be slight, but lots of genes having a small influence will have a combined additive effect. The way in which these conditions are inherited is not straight forward; hence the name complex inherited disorders. These complex diseases are usually seen across many different breeds and are also described in both cross breeds and mixed breeds (taken from KC page link below) When breeding a breeder will consider the scores for both sire and dam. The hips are scored individually then added together and the total is scored out of 106. (0 being the best and 106 the worst) ​ The current breed Scores taken from BVA: ( Breed dogs scored in 15 years = 156 dogs 15 year Range 2- 68 and Median Score 12 5 year Range Median Score 11 Breed Specific Statistics – 1 January 2001 to 31 December 2016 What is Elbow dysplasia? Elbow dysplasia is a condition where the elbow joint does not develop correctly. As the dog matures, the joint undergoes wear and tear and the joint deteriorates, leading to a loss of function. This can cause varying degrees of pain, discomfort, stiffness and lameness.
  • JDCM Juvenile Dilated Cardiomyopathy
    Juvenile Dilated Cardiomyopathy (JDCM) is an inherited fatal disease in young Portuguese Water Dogs that is caused by a recessive gene (both parents of a puppy must carry the gene to produce the defect). Puppies affected with JDCM die suddenly or with very little warning usually between the ages of six weeks to seven months old. There have, however, been cases reported younger than six weeks as well as older than seven months. The signs and symptoms of JDCM include a 12 to 48 hour onset of loss of appetite, decreased energy level, vomiting, and difficulty breathing. Some pups have no physical signs or symptoms at all, may just collapse and die, or are found dead by the breeder or new owner. At this time, there is no known cure or treatment but there is a way to prevent producing JDCM affected puppies. ​ We now have a DNA gene based test, based on a cheek swab or a blood sample, which will determine if a dog is Normal (not carrying the gene) or is a Carrier of the JDCM gene. All breeding animals can be tested to determine their status, thus avoiding the breeding of two JDCM carriers and producing puppies which will die of this deadly disease. ​ Researchers at the University of Pennsylvania have recently developed this DNA test for detecting dogs who do not have the JDCM gene and dogs who are carriers of the JDCM gene. Breeders are now able to have their breeding animals tested for Normal or Carrier status. Never breed two carriers together or you will produce puppies which will die. ​ Dogs used for breeding should be DNA tested for JDCM status and that one of a breeding pair, either the sire or the dam, be tested as Normal. It is important that all prospective puppy buyers discuss Juvenile Dilated Cardiomyopathy with breeders. Ask if the parents have been tested for JDCM and what their status is, Normal or Carrier. A puppy from a JDCM DNA tested Normal sire or dam will not be affected with this fatal disease. ​ More information can be found from the link below
  • PRA (prcd) Progressive Retinal Atrophy
    (progressive rod cone degeneration or disease): This is a condition of the eye in the Portuguese Water Dog that causes degeneration of the retina and eventually will cause blindness. It is usually a late onset condition. The condition was first reported in the Portuguese Water Dog in 1990 and since that time research into the condition has produced a DNA mutation gene test to identify dogs that either carry the gene (carriers) do not carry the gene (clear) or affected by the condition (affected). Mode of inheritance is Autosomal recessive. Carrier and Affected dogs should only be bred to Clear dogs to avoid ever producing prod puppies. Testing for PRA (prod) is done by blood sample or by Cheek Swab and the laboratories carrying out this test are Optigen in the USA ( and Laboklin ( A new form of PRA which is early onset has been discovered in the PWD in 2017 and DNA-based test has been developed to target the mutation responsible for Early Onset PRA (EOPRA) in the Portuguese Water Dog. For more information click here: OptiGen - Tests offered - Canine genetic testing, Ithaca, New York
  • CDDY Chondrodystrophy with IVDD risk
    Chondrodystrophy (CDDY and IVDD) and Chondrodysplasia (CDPA) | Veterinary Genetics Laboratory (
  • MO-PWD Microphthalmia Syndrome
    Penn Vet | Genetic Tests (
  • Addison's disease (no DNA test available)
    Find more information at:
  • Paroxysmal Dyskinesia (no DNA test available)
    Fact sheet for more info:

Many health problems can affect any breed and the use of available health tests can not only assist the breeder to make informed breeding decisions but also add valuable information to build our breeds genetic profile for the future.


Breeders will be considering the health of the stud dog they wish to use and the bitch to breed from. The Club has a list of recommended tests and how to use them.

Also find below links and additional information on some of these health conditions 

Health Research

Part of learning about our breed is the sharing of information so new knowledge can be acquired and a confidential record kept by the club. In the coming year we hope to explore our breeds health using a health questionnaire /survey.

If you have an active interest in taking part in research then these 2 projects are currently available:

  • GOdogs - Investigating the genetics of obesity in dogs 

  • Generation Pup - The first study to follow all breeds of dog throughout their lives

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