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Health issues

For the latest health information please see the Health sections on the Portuguese Water Dog Club of Great Britain website: 

or the PWD Club of America site:

We believe it is essential that all PWD breeders should fully health test their breeding dogs. We do this and we will gladly and openly share the results with prospective owners and explain what they mean.


Whilst the PWD is a relatively hardy and healthy breed, as with all breeds, there are certain known health conditions that can affect breeding. Different health issues can appear at any age so look for a breeder who undertakes all relevant tests before mating and doesn't breed their dogs until they are at least two years old. 

Many health problems can affect any breed and the use of available health tests will assist the good breeder to make informed breeding decisions and add valuable information to build the breeds genetic profile for the future. The more breeders who undertake the tests the more accurate the data we will have to ensure a healthy breed going forward. If a breeder has done no health tests - then walk away.


Whilst these issues don’t affect all PWDs it is important to be aware of the following if you are considering the breed:

X-ray tests

  • Hip Dysplasia 

  • Elbow Dysplasia

DNA  / gene testing

  • Progressive Retinal Atrophy (PRA)  & Early Onset PRA (EOPRA)

  • JCDM Junior Dilated CardioMyopathy

  • GM1-Gangliosidosis

Others tests & health issues

  • Improper coat 

  • Addison's Disease

Kennel Club inter-breeding coefficient

Currently, there are no mandatory veterinary screening schemes or DNA tests relevant to this breed under the Assured Breeder Scheme, however, we test our dogs for all currently available tests at the time and we believe that all reputable breeders should and would want to do this too.  If they don’t test or won’t disclose the results, I would have to ask why and I certainly wouldn’t have a puppy. Most of the results from breeders who test are freely available on the Kennel Club ( KC) Website. Some labs automatically put the results on the KC website but if they didn't have a licence to do this it may say “results with breeder”. The breed tests have just changed again to “My dog DNA “,  a new laboratory, and its not clear whether they will be automatically submitting uploaded results to the KC for each dog.  All reputable breeders test and share the results for their breeding PWD.


You really have to question why a breeder won't test - it costs around £800 for the full set of tests which is nothing in comparison to the income from a litter of puppies. If a breeder only ever has one litter of 10 puppies then it is only £80 per puppy. Of course the test results last a life time and cover all litters the bitch or dog has thus reducing the effective cost to £20 per puppy over four litters.

Please ask your breeder about their test results and ask to see their paperwork. It is not only the responsibility of all breeders but also the responsibility of everyone enquiring about puppies to ensure the healthy continuation of this rare breed.

​X-Ray tests

Hip Dysplasia  

Hip Dysplasia is a heritable and complex condition in which the thighbone doesn't fit snugly into the hip joint. 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 on one or both rear legs, but you may not notice any signs of discomfort in a dog with hip dysplasia. As the dog ages, arthritis can develop. Hip dysplasia can be hereditary, but it can be made worse by environmental factors, such as rapid growth from a high-calorie diet or nutritionally depleted diet,  injuries incurred from over-exercise when too young, climbing stairs under a year old, jumping or falling on slippery floors. Scoring for Hip Dysplasia is done by the British Veterinary Association (BVA) / Kennel Club (KC) scheme - a dog’s hips are X rayed and the plates are evaluated by a team of appointed specialists to determine anatomical and pathological changes indicative of hip dysplasia. The scores shown are one for each hip and then the combined total. The range is from 0 to 106 (0 being the best score and 106 being the worst).


A score would look like:            left: 3 / 53      right: 3 / 53          total hip score: 6/106

The current BVC/KC screening (2019)  PWD  5 year mean score is 14.3 (median score is 11.0) 


A good breeder will 

  • always do the tests before they breed. If a breeder says it isn’t worth doing then walk away. Some also don’t test saying the results aren’t reflective because there are too few tested. If only they bothered to test then the numbers would increase and the research and understanding of hip dysplasia in the breed would increase. Some simply don’t bother because it costs.

  • know the test results for both the breeding bitch and dog.

  • only breed if each dog’s total score is near or below the average. 

  • know the hip score of the tested dog’s parents and grandparents and the scores should be declining over time. 


Elbow Dysplasia

Elbow dysplasia is similar to hip dysplasia - 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. The x-ray tests in the UK are only starting to be done by breeders. It is scored out of 3. A good breeder will be doing this test because the more they are done the more information the breed will have to see if there are any issues in the breed. Currently, a good breeder would expect to breed PWD with an elbow score of 0 out of 3. 

DNA Gene tests

Basic background genetic understanding to help you understand test results. 

All genetic / DNA tests look for a specific gene or marker for a disorder or disease and it separates dogs into three groups according to their genetic status:

  • Normal/Clear: the dog does not carry the gene; will never develop the disorder or disease and won't pass it on to the puppies.

  • Carrier: the dog is a probable carrier of the gene but they do not have and will not develop the disorder or disease. However, they will pass on their carrier genes to the next generation. Just like humans, we all carry various genes which will only be an issue and affect your babies if you mate with another carrier or affected person. If you are a carrier the disease will never show itself in your offspring if you mate with someone without the gene. 

  • Affected:  the dog not only carries the gene but will be affected and suffer from the disorder. They will pass on the disorder to the puppies.


A good breeder can ensure, through selective breeding, that none of the puppies will be affected. They will always

  • do the tests well before even considering breeding.

  • know the results from both parents before breeding.

  • will always ensure at least one parent is clear (normal)

  • they will use a table like the one below to make sure that no puppies have the risk of being affected.



















You can see that you need to have at least one parent to be normal/clear to ensure that there is no risk of having puppies affected with the disorder. These are the yellow boxes on the table.

  • Clear with Clear will produce clear puppies    IDEAL

  • Clear with Carrier will produce clear and carrier puppies QUITE ACCEPTABLE as no puppy will become affected.

  • Carrier with Carrier will produce 25% affected puppies  BAD 1 in 4 puppies will suffer from the disease.

  • Affected with Carrier will produce 50% affected puppies   BAD 1 in 2 puppies will suffer from the disease.

  • Affected with Affected will mean 100% - all puppies will be affected.  BAD as all puppies will suffer. 

Some breeders do not test their breeding dogs saying that they are clear by hereditary, meaning that the parents or grandparents were clear.  This is only true if the line has actually been recently tested and they can prove the results were clear. If the line has not been tested then you can not say it is clear. The Kennel Club advises always retesting every 2nd generation to make sure. The American PWD Club says that it should be no more than 1 generation gap. Make a breeder prove they have done this. 

It is vital that if a breeder doesn't do the tests, won't share them with you or says they aren't worth doing then walk away. They should always want to know if their breeding bitch and dog are possible carriers. Why would a breeder not do the tests and risk the certainty all or some of the puppies being affected and contracting the disorder or disease. I think you are probably getting the message by now!

gm1 table.jpg
Dog Genetics.jpg

DNA / Genetic tests

prcd-PRA rogressive rod cone degeneration - Progressive Retinal Atrophy (prcd -PRA)

This is a degenerative eye disorder that eventually causes blindness from the loss of photoreceptors at the back of the eye. PRA is detectable years before the dog shows any signs of blindness. Fortunately, dogs can use their other senses to compensate for blindness, and a blind dog can live a full and happy life. All reputable breeders have their dogs tested.

Breeders take the Optigen DNA gene mutation test for prcd-PRA rather than the older  'marker' test previously offered.. The test provides a means to eliminate prcd-PRA from the Portuguese Water Dog and it  identifies the gene responsible for the Progressive Rod Cone Degenerative (prcd) form of PRA common to the PWD. Like all DNA testing, it separates dogs into three groups of normal (clear), carrier and affected. 

Juvenile Dilated Cardiomyopathy (JDCM)

This is an inherited heart disease that causes sudden death in puppies between the ages of five weeks and seven months. It is a recessive gene and if both parents carry the gene then the puppy will be affected. 


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 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. The only way is for breeders to prevent producing affected puppies by knowing the test outcomes of their breeding dogs and avoiding breeding carriers of the gene. 

GM1-Gangliosidosis  (GM1) 

This is an inherited neurological / storage disorder that causes a fatal disease in puppies who rarely live beyond 6 months. Storage Disease (GM1) is a recessive genetic disorder caused by a lack of an enzyme and allows the buildup of toxic substances in the nerve cells. It is fatal to puppies produced by two carriers. PWD puppies affected with GM1-Gangliosidosis develop nervous system manifestations including ataxia, seizures and changes in temperament. A DNA test has been developed to determine whether dogs are normal or carriers. This is currently tested by OptiGen and has dramatically reduced the incidence of both carriers and affected puppies. 

If breeders don’t do these tests for both parents or one of them is affected - then walk away. You have to ask yourself why the breeder won’t do the tests. If they don’t do the test then they don’t know if their puppies are affected. Why would you give a puppy to a new family not knowing if there is a chance it they will be affected by the disoredr later in life or could die at 6 months? It's still the same message - I hope it is getting through!

Other health issues:

Improper Coat test

Improper coat (IC) is a genetic mutation found in purebred Portuguese Water Dogs, probably originating with the inclusion of some other breed at some point in our history. It is not a health issue. It is a coat issue with the dogs having a coat that does not grow long and stays short to the skin and will shed. An IC Portuguese Water Dog is healthy and in every other way and can be as correct to the Breed Standard, structurally and mentally, as any of its properly coated littermates. The test just allows breeders to breed out this mutation and have dogs with structurally correct curly or wavy coats. 

Addisons Disease

Addison’s disease is a dysfunction of the adrenal glands and is also known as hypoadrenocorticism or adrenal insufficiency.  Many vets often believe an ill dog is suffering from Kidney failure. It means that Addison's should always be a considered diagnosis when a dog is suddenly ill with vomiting, diarrhea, lethargy or dehydration and there is no apparent reason. In short, testing for Addison's disease should be part of the vet's diagnostic process with any really sick dog when the cause of the illness is not clear.

Addisons is a disease which can and does affect all dogs, but it is thought that PWD amongst a few other dogs may have a predisposition to it. This, however,  may simply be a result of American PWD breeders and owners being far more aware and so the breed is tested more often and therefore thought to have a greater occurrence - whereas, in reality, it may be in all breeds. It is not known to be a major occurrence within the UK breed but it certainly does exist. Different research in the USA on limited numbers of dogs put it anywhere between 0.6% and 12.8% - a massive and highly inconclusive range from the various research. The research at the moment is not definitive. Two sets of US scientists agree that the disease is an inherited trait but the mode of inheritance is not agreed. Currently, there is no dna test for this disease.


One US research paper has a link between the breed coefficient and the likelihood of Addisons. i.e the more closely related the parents are the higher the rate of the disease. That is why we always recommend that you search out a breeder who does the breed coefficient before breeding. The score is out of 100 and the breed average is currently 9.1. The higher the score the more genes the parents have in common. A score of 25 is the equivalent of shared genes between grandfather & grand-daughter. Whilst it doesn't have a direct indication of Addisons or any other genetic issues - it can help to ensure breeding isn't too close and ensures a widening and strengthening of what is currently a very small gene pool. But this research is also very limited and inconclusive.


The symptoms of Addisons are so incredibly wide and varied that it is very difficult for a vet to diagnose it to one particular cause. Vets may try various treatments first to rule out other more common causes. In the end, many vets often believe an ill dog is suffering from Kidney failure and treat accordingly. It means that Addison's should always be a considered diagnosis when a dog is suddenly ill with vomiting, diarrhea, lethargy or dehydration and there is no apparent reason. In short, testing for Addison's disease should be part of the vet's diagnostic process with any really sick dog when the cause of the illness is not clear. As a pet owner, it is worth talking to your vet if your PWD is very ill and making them aware that this could be a cause.


It is not something I unduly worry over as a PWD pet owner - if the breeder has done the required health tests and the breed coefficient then they are doing everything to reduce the likelihood of all genetic issues. Good breeders will also record any known cases in their breed lines (that is if the vets have undertaken the test to confirm the dog has it and then the owners have informed the breeder) It is something PWD owners should be aware of if their pet becomes ill with symptoms so they can talk to their vet.

Eye issues:

Distichiasis is a painful eye disorder where too many eyelashes grow around the eyelid. This is typically where two hairs grow out of one single follicle. The condition needs to be treated as soon as possible otherwise a dog's corneas many become ulcerated which might cause permanent damage to their eyes.

Entropion is an abnormality of the eyelids in which the eyelid rolls inward. This inward rolling often causes the hair on the surface of the eyelid to rub against the cornea resulting in pain, corneal ulcers, perforations, or pigment developing on the cornea which can interfere with vision.

If you have got to the bottom of this page, you have surely got the message by now! Test, test, test!! :)

Breed Coefficient: Current breed average is 4.9 (2022)

A free Kennel Club test aimed at reducing in-breeding and helping ensure PWD remain healthy and genetically diverse in what is a very limited PWD gene pool. Search out a breeder who does the breed coefficient before breeding and ensures and can prove it is low. You can check it yourself for free on the KC website - all you need is the kennel names of both parents and a good breeder will willingly provide this information and show you how to find the results. Ask a breeder for the coefficient for all of their last litters - a good breeder will be willing to tell you.

See the KC website for more information:

The score is out of 100 and you should only breed at or below the breed average which is currently around 4.9 (2022) -  the lower the better. The higher the score the more genes the parents have in common and the increased likelihood of passing on genetic issues.  Scores indicate:

  • 0% = a dog with two apparently unrelated parents (based on all available pedigree information)

  • 12.5% = the genetic equivalent of a dog produced from a grandfather to granddaughter mating, or the mating of a half-brother/sister

  • 25% = the genetic equivalent of a dog produced from a father to daughter mating, or the mating of full-brother/sister.

This quick and free KC check needs to be done to ensure breeders minimise the health issues from mating to a close relation. It ensures a strong and diverse gene pool. Ask yourself why it is not a good idea to breed with your parent, grandparent or sibling! If you are in doubt please ask for advice. If a breeder doesn't know about it, don't do the check before mating or they just let their dogs mate as they wish - we would advise you to walk away. 

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