Now all of us can understand the horror of learning that a dog that is one’s pride and joy has transmitted the gene for something nasty like JKD, especially as in a recent case the dog was one of the top dogs in the breed. The natural response is to take a defensive position and question the evidence. But the evidence here is strong. The critical factor is that a Juvenile Kidney Disease (JKD) is present in Boxer s and it is inherited; it is found in family groups, and this is the key element in its diagnosis. In this particular instance, the sire has produced four veterinary diagnosed kidney cases and is the grandsire of another published case. In addition it has a close relative who has produced several JKD cases, so all the evidence needed is there. There is not a doubt in the world that the kidney condition here is the inherited one.
But what else has been said against this conclusion?
1. It is stated, correctly, that a case was found NOT to have Renal Dysplasia (RD) on PM, this defined by the presence of premature cells in the glomerulus of the damaged kidney. The Swedish Veterinary School uses for this criterion for its research into Boxer kidney disease. This is fully justifiable for their purpose, but only a minority (1 in 8 cases) of Boxer kidney deaths are diagnosed as having RD (premature cells detected). The majority don’t, but still have a chronic kidney failure which is inherited (JKD), and this is the important point. One could say that RD is JKD with the premature cells additionally being found, and that RD and JKD are basically one and the same disease, as actually indicated by the finding that kidney cases with these cells evident (RD) and others without (JKD) can be found within the same families and even within the same litters. The absence of a specific RD diagnosis is therefore of little relevance for our purposes. The important point is that these cases have an inherited chronic kidney disease AND belong to a family within which the disease has repeatedly occurred. Evidence of the inheritance is THE vital diagnostic feature above all else.
2. It has been reported that that both parents of one of the JKD cases in question had typed negative with the Canadian Dogenes Renal Dysplasia test, implying they did not carry the responsible mutation. But the Dogenes test has been discredited even by the journal that published the original findings (Expression of concern: Novel allelic variants in the canine cyclooxgenase-2 (Cox-2) promoter are associated with renal dysplasia in dogs. PLOS ONE Editors..PLoS One. 2012;7(11):e49703. doi: 10.1371/journal.pone.0049703. The test would seem to be invalid, as this published case actually indicates. The gene test does screen for a particular mutation (in the Cox-2 gene) which seemingly is present in many Boxers, but this does NOT appear to be the gene responsible for the known inherited Boxer JKD.
3. One bitch of this breeding had a uterine tract infection, and it has therefore been suggested that lack of treatment of UTIs can cause the chronic renal failure. But UTIs are not uncommon in JKD cases. They are thought to be a CONSEQUENCE of the kidney malfunction and in fact have often led to the detection of JKD, but they are NOT the cause.
4. It has also been suggested that antibiotic treatment of young puppies can cause renal disease in adulthood. This concept is without any scientific evidence whatsoever, and it could never be imagined that vets would give treatments to pups that they knew would cause a renal failure later. And were there any risk at all, it would be true for all other breeds, whereas the incidence of chronic kidney disease in Boxers, according to the published insurance statistics, is 45 times higher than that observed in other breeds.
5. It is stressed that there are various environmental causes of kidney failure, such as drinking antifreeze, but one cannot imagine rare accidental events like this notably occurring in family groups of Boxers, in different ownerships, and living in various parts of the world, as seen in this family group.
The above are my comments as a geneticist but I hope to get a renal expert to add a specialist veterinary viewpoint. This will be published on www.BoxerJKD.com. I expect no important disagreement.
I would stress that the reporting of JKD cases is not an attack on any person, dog, or kennel. It is only a presentation of pedigrees from established cases. These, when put together, clearly demonstrate the inheritance of the disease and this will help everyone avoid producing further affected Boxers. The battle is with the disease and to win we all have to work together.
At this time when the magnitude of the problem and distribution of the gene responsible in the breed is barely understood the only breeding advice that can be recommended is that dogs and bitches that have produced JKD should not be bred from further. After all, the only way of being certain of perpetuating the problem is through continuing to breed from such animals.
Finally, I would urge those that have concerns about any of this to write to me (firstname.lastname@example.org) or send a message through www.boxerjkd.com and every effort will be made to resolve questions directly or with the help of specialists in the rapidly developing field of canine renal disease. This should not be a battle between people but rather a battle between all of us in Boxers and this lethal inherited disease.