Breeding recommendations for UK Breeders

As is evident from the pedigrees, JKD is widely spread throughout the show and other sections of the breed in the UK.  Breeding away from the problem through the use of perceived clear lines is therefore almost impossible and indications that the disease is occurring in dogs from other countries worsens the problems.  
The immediate message is that actions to deal with the disease must be limited to avoid decimation of the breed.

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Our preliminary suggestions for current breeding based on a recessive gene inheritance for JKD are: 
First and foremost, we need very active screening for all possible Boxer JKD cases with follow-up checks upon affected pups by their breeders, and reporting of all the findings.  In effect, breeders should actively look for cases arising in their stock and not rely on getting word from puppy owners alone.

1. To reduce the incidence of the disease and reduce the incidence of the gene responsible, it is vital that all animals that have been the sire or the dam of a dog showing evidence of kidney failure be withdrawn from any further breeding.  The risks of other causes of kidney failure other than by Boxer JKD can be taken to be small. 


2. Recognising that litters of affected pups may contain not only carriers, but also genetically affected (sub-clinical) individuals, it is inadvisable to breed from the siblings of confirmed Boxer JKD cases.


3. To reduce the risk of producing affected pups, breeders should avoid close inbreeding and/or doubling up closely on ancestors found to produce Boxer JKD.


4. It would be best if breeders assumed that there are no clear lines anywhere (which may actually be the case), but there will be clear dogs in all breeding lines, British, Continental and American.  Breeders should therefore continue to breed as they always have – for the best dogs – but include the screening of all puppys up to 2 to 3 years of age. Followed by the withdrawal of any sires or dams that have produced any cases of Boxer JKD from all future breeding.


5. It is vital that breeders do NOT rush to where they IMAGINE there are clear lines to look for stud dogs. This will only reduce genetic diversity of the breed further and may not successfully avoid the disease either.


6. To increase the chance of finding stud dogs that are clear of the Boxer JKD gene. The focus should be on bringing as many dogs onto the breeding scene as possible and abandoning the standard practice of giving a small numbers of stud dogs almost all of the stud work.  Avoid the 'Popular Sire' syndrome. This is also becoming a necessity for the survival of the breed, let alone for dealing with Boxer JKD.


7. These dogs should be available at stud to ALL quality bitches (other than siblings of Boxer JKD cases) but always with total commitment to identify and withdraw from breeding those parents that produce any affected progeny.


8. A further option both for detection of developing Boxer JKD and for selection of breeding stock would be use of the urine specific gravity screen (USG) which is highly sensitive for detecting any developing kidney failure.  This has most application in younger animals which are at most risk of developing Boxer JKD but may pick up indications of the disease in older animals.  Here it is of great value for screening bitches prior to breeding.


9. STOP PRESS, a new screen for ‘symmetric dimethylarginine (SDMA)’ as a biomarker for kidney failure, if validated, may prove of vital use for identifying dogs with partially damaged kidneys.

The key messages for dealing with Boxer JKD and maintaining the health of the breed are: 
Reduce the Coefficient of Inbreeding (COI)
Screen and share any cases of JKD
Limit the use of Popular Sires
Avoid all inbreeding

Photo reproduced with full permission of Dreamweavers Photography New Zealand