­­­Health Testing

We take health testing extremely seriously.

Families searching for a puppy have long been advised to check that parents have been health tested in order to have the best chance of having a healthy puppy. The huge problem with this is firstly that simply being health tested doesn't guarantee healthy puppies, it's the results of the health testing that are important! These results need to be carefully analysed and used  to make decisions as to breeding suitability based on whether puppies  are at greater or lesser risk of inheriting disease.

The recent advent of DNA health testing means that it's possible to ensure that no puppies can be born with any inherited disease that can be tested for. It's now possible to test for a multitude of diseases, some which can affect dogs of any breed and some more breed specific.

With diseases that cannot be DNA tested for, such as hip dysplasia, checking the parents for signs of the condition has never been satisfactory as these results in isolation can be misleading as they do not accurately predict whether progeny are likely to be affected with the condition.  Parents with good hip scores can produce severely dysplastic puppies, and conversely parents with bad hip scores themselves can produce puppies whose own hips show no problems. This is why Estimated Breeding Values (EBVs) are vitally important (see below).

Another factor that people are mindful of is that health and vitality is directly related to the presence of common ancestors, in other words how many ancestors are related to each other (how inbred the dog is, also known as the Coeffecient of Inbreeding (COI)). This is one reason why so many people favour crossbred dogs over purebred, as the parents of crossbred dogs cannot share ancestors in common. The positive effects of this are known as hybrid vigour, or heterosis. 

In recognition of the HUGE significance of these factors in determining the health of puppies, there are now ways of determining genetic risk for diseases for which DNA testing isn't available, ie how likely a particular dog is to pass on hip dysplasia to its offspring. It is also now possible to use a calculation to show the degree of inbreeding in any particular dog.  These 2 factors, along with the recent introduction of  DNA health testing covering a multitude of inherited diseases, have a massive impact on the health of the dog's offspring and using these 3 different tools give a hugely more accurate prediction as to the health of their progeny than has previously been possible.

The first calculation defines  the degree of inbreeding-known as Coefficient of Inbreeding or COI.

This is hugely significant because the lower the COI in an individual dog the lower the risk of deleterious (disease creating) recessive genes doubling up which would result in disease creation. A low COI (lower level of inbreeding) also results in dogs which have a much increased likelihood of having strong, healthy functioning immune systems bringing increased disease resistance, increased fertility and increased longevity. These effects are also known as Hybrid Vigour or heterosis and this is the very reason that many people choose crossbreeds over purebred dogs often having previously had negative experiences with health related issues in their purebred companions. However, if crossbreeders are not ensuring that their parent dogs have low COI's themselves then the positive effects of hybrid vigour in their offspring are obviously greatly reduced and these offspring are therefore at risk of suffering the negative effects of inbreeding (inbreeding depression) passed down from their parents, which include higher risk of disease, lower functioning immune systems and decreased longevity. This is because the COI of an individual dog does not give you an idea of the COI of their ancestors. For example, an F1 Goldendoodle will have a COI of virtually zero because there will be minimal similarity between a Golden Retriever and a Poodle. However, the Golden Retriever parent and the Poodle parent themselves could have much higher COIs depending on how related their parents were, and therefore have the resultant negative effects to pass onto their offspring.

The second calculation defines the statistical likelihood of a dog passing on specific genetic disease, which again is hugely significant. This calculation is very much more accurate in determining the genetic risk, ie the risk of passing the condition onto puppies, than looking at an individual dog's hip or elbow scores. This is because with traditional hip scoring you are merely looking at the dog in question's hips to see how healthy they are, but you are not looking at the genes they carry for this condition and therefore can pass onto offspring. Therefore hip scoring alone is of very limited use in determining whether a dog will pass on hip dysplasia to its offspring. Research has shown that at best, hip dysplasia has only 25% heritability, but probably considerably less than this! A much more accurate way to determine the risk is by, as well as hip scoring the dog in question, also looking back through many generations of the dog's ancestors for prevalence and severity of the disease. By doing so, a means of calculating a specific dog's genetic risk (ie risk of passing the diseases onto their offspring) has been devised. This is a complex algorithm but it is now possible to look up this statistical value for certain breeds, known as an Estimated Breeding Value (EBV), on a calculator which can be found on the Kennel Club website. Golden Retrievers and Irish Setters are amongst the first breeds for whom data has been input so anyone can look up the EBV of any KC registered Golden Retriever or Irish Setter on the relevant section of the KC website

By using EBVs- you are able to much more accurately predict the dog's relative risk of passing on genetic disease. This gives a picture of far greater accuracy of the dog's genotype (genes they carry) than hip and elbow scoring alone which merely accesses a dog's phenotype (their own hips and elbows).  This is a really huge move forward for breeders as they are able to make very much more accurate decisions as to inclusion of dogs in their breeding programs than was possible before by using just hip scoring, which we now know is a very poor indicator of the genetic risk. Breeders who are ensuring that their breeding dogs also have EBVs of average or better (marked as green on the Kennel Club scale) for their specific breed are doing everything they can to reduce the risk of their puppies inheriting these genetic conditions. Coupled with only breeding from parent dogs whose COIs are as low as possible and definitely lower than the breed average, and also by using all available DNA testing, the puppies produced from these parents will statistically have a very much increased likelihood of stronger immune systems, increased longevity and freedom from inherited genetic disease.

In view of the huge significance on the potential health of their puppies,  all breeders should be in a position to prove to potential puppy owners that the COIs or their parent dogs are lower than the breed average, and that the EBVs of their parent dogs are also better than average. By doing so, along with carrying out vital DNA testing and ensuring that they are only breeding from one clear parent (thus ensuring that no puppies affected with the particular disease can be produced), this shows that they have done everything in their power to breed from parents who have the greatest likelihood of healthy puppies. The tide is beginning to turn as these new tools and updated knowledge is filtering through to breeders, and responsible, ethical breeders who have the health and wellbeing of their puppies to the fore will be making use of these and will be able to provide evidence of this to their potential puppy owners.

Here at Kizzabella we are making extensive use of the above tools. We only breed from dogs who have low COIs and also EBVs for hips and elbows that are better than average (green on the KC scale). We show concrete evidence of this to our potential puppy owners. In addition, our boys are extensively DNA health tested AND ARE CLEAR FOR OVER 160 CONDITIONS!! This will ensure that we are never going to produce a puppy with a disease that could have been prevented by testing. Our boys have always all been  DNA prcd PRA clear but as there are now opportunities to do much more extensive health testing we are using these tools to further ensure that our puppies are free from EVERY inherited disease that can be DNA tested for.  Again we are able to show the DNA clear certificates to potential owners which will prove that our puppies cannot be affected by any diseases for which there are DNA tests available.

 It is a immense responsibility to bring puppies into the world and as responsible breeders we do everything in our power to increase the likelihood of robust health in our puppies by means of using the latest research and tools as described above.  No breeder should be doing anything less! To bring puppies into the world who have a high risk of ill health and decreased life expectancy is highly irresponsible and unethical! Unfortunately it is currently definitely not  common practice to use these tools. Our puppy owners can be secure in the knowledge that we go way above and beyond to ensure that our puppies are as healthy and robust as they can be.

DNA TESTING Our parent dogs are all paired to ensure that puppies cannot be affected by ANY of the above recessive genetic conditions AS AN ABSOLUTE MINIMUM*. In most cases our puppies have one parent who is EXTENSIVELY DNA CLEAR OF OVER 160 CONDITIONS hence their puppies cannot be affected*(Please note that currently we are testing for PRA rcd4/LOPRA results pending).

Our families are given full details of parents’ health testing including hip/elbow scores, DNA test results, EBVs and COIs and in most cases also grandparents and sometimes earlier generations too. Our crossbreed dogs all have fully traceable linage back to their KC registered heritage.

Hip Scores should be around or below average and the dog must have a lower than average Estimated Breeding Value (assessment of multiple generations to better determine the genetic likelihood of a dog passing on the condition). Currently for Goldendoodle breeders EBVs are only available for Golden Retrievers. However it is still possible to check several generations for incidence of hip dysplasia and to only choose dogs to include in breeding programs who have good scores over several generations. Hip scoring/EBV’s mandatory for all larger breed parents regardless of the status of the other parent. This is because hip dysplasia is inherited via a complex mode of inheritance and therefore a low score in one parent does not rule out the possibility of the disease developing in offspring.

Elbow Scores (are not a recommended/required test for Irish Doodle breeders) should be 0:0 (0:1/1:0 is acceptable but less desirable) only and the dog should have a lower than average Estimated Breeding Value (assessment of multiple generations to better determine the genetic likelihood of a dog passing on the condition).

It is important to be aware that dysplastic puppies can still occur in litters where both parents have good hip/elbow scores and good hip/elbow scores in previous generations. However as breeders it's vital that we do everything we can to minimise the risks.

DNA Testing. Breeds that can be affected by a condition are marked with a √in the tables above. It is imperative that one parent in a pairing is DNA clear for the disease in question. This will ensure that no puppies in the litter can be affected by the disease. A breeder therefore needs to be using pairings that include one clear dog for each of the possible inherited diseases to ensure that no puppies can be affected by the condition. If using one clear parent for the specific condition, the puppies cannot be affected therefore the status of the second parent for that particular gene isn’t relevant to the health of their puppies.

Most diseases that can be DNA tested for are breed specific so if the specific disease is not found in a particular breed they will be automatically classed as clear for that disease.

There are some DNA tests which we carry out that are new to the UK so as yet many breeders won’t be carrying them out.  Longer term it is hoped that breeders will be ensuring that they are only breeding from a pairing that cannot result in puppies affected by any preventable health condition. There are also several diseases that can be found in numerous breeds and aren't breed specific, so for these diseases it is necessary to have one clear parent. 

Please don't hesitate to contact us for information or advice about health testing.