Breed Club testing for haemophilia in male German shepherds

Haemophilia is a hereditary disorder that leads to anomalies in the blood’s ability to clot, due to the lack of what is known as Factor VIII, a vital element in clotting and wound healing. Dogs that are deficient in Factor VIII may potentially bleed prolifically (internally and externally) any time they get a cut or minor injury, as their blood will not clot and scab properly to heal the wound.

This means that even a small injury can be critical and even potentially fatal for affected dogs, and so poses a significant risk to the health and wellness of haemophiliac dogs.

Whilst haemophilia affects every dog differently and some dogs will have only minor clotting problems, the fact that invisible injuries and internal bleeds can go unnoticed poses an additional risk. Dogs that have a severe form of the condition may even begin to bleed internally spontaneously, which tends to lead to a short lifespan and premature death.

As a hereditary health condition, certain breeds of dogs are considered to be at much greater risk of inheriting the condition than others, and up until around twenty years ago, the German shepherd dog was at the top of the list in terms of risk.

It is also important to note that it is male dogs that are particularly at risk, and haemophilia in female dogs is very rare-however, females can pass on the condition to their young, and so, lead to further affected males.

Large-scale breed club health screening of German shepherd dogs prior to mating has significantly reduced the occurrence of the condition within the breed, and as such, the German Shepherd Dog Breed Council of Great Britain strongly encourages breeders of German shepherds to get their own stud dogs tested prior to mating.

In this article we will look at haemophilia in the German shepherd dog breed in more detail, including why testing is still advised, and how to decide if you should get your own dog tested. Read on to learn more.

More about haemophilia in German shepherds

Exactly why haemophilia became prevalent within the German shepherd breed in the first place is the source of some debate. Around 25 years ago when it first became evident that haemophilia was appearing within a lot of dogs of the breed, there were relatively few genetically diverse German shepherds within the breed pool of show dogs and desirable breeding stock.

One very famous and popular stud dog, Cantro Von Der Wienerau is thought to have been the likely source of the introduction of the condition into the breed. Whilst the dog himself was not tested, he died at a young age in a way that indicated haemophilia, and the female dogs that he sired prior to his death tested positively as carriers.

Since that point, virtually all cases of haemophilia within the German shepherd breed can be traced back along the breed line to that one original stud dog and his offspring.

Why are male dogs at risk but not females?

Haemophilia is an interesting condition in that it only generally affects male dogs due to its mode of heredity (with the highly irregular exception in very occasional females) but is carried through the female side of the bloodline.

Haemophilia A, the variant of the condition that affects German shepherds is inherited by means of X-linked recessive heredity, or the female side of the sex gene, with females being designated as XX and males as XY. A female dog needs to inherit two copies of the faulty gene in order to be affected by the condition, whilst males only need one. This is why the condition is virtually unheard of in female dogs, but females are the main carriers, as they have two “X” genes and only one needs to be affected, whilst males only have one.

Male puppies born to a female carrier have a 50% chance of being affected, and a 50% chance of being healthy. Females that are known carriers should not be used for breeding, due to the risk this poses to their male offspring.

What sort of German shepherds should be tested prior to breeding?

Because the condition is passed on through the maternal lineage, it seems logical to most people that it is female German shepherds that should be tested for the condition prior to breeding, but this is not the case-only male dogs can be tested reliably.

Blood tests on male dogs can detect haemophilia and so, male dogs can be certified as either clear or affected; however, due to the way that the condition is inherited, blood testing cannot determine carrier status in the female, which is why it is the male dogs of the breed are tested.

If you own a male German shepherd and wish to breed from them, it is important to have them tested first, in order to ensure that they are clear and cannot pass the condition on. If you need to get your dog tested, simply ask your vet to run a blood panel for the condition and let you know the results.