Factor VII deficiency (FVIID for short) is a deficiency of factor VII, which is necessary to allow the blood to clot properly. It is a hereditary health condition that cannot be caught or transmitted between dogs other than by means of being passed down in the breed line, and can lead to anything from a mild to a moderate inability to clot the blood when necessary, such as if the dog gets a cut or a graze.
The condition is similar in its presentation to other bleeding and clotting disorders such as haemophilia and Von Willebrand’s disease, and occurs because affected dogs do not produce enough Factor VII, which is synthesised in the liver of healthy dogs. Factor VII is a type of protein that is necessary to allow blood to clot and coagulate properly, and a lack of it can cause excessive bleeding either internally or externally if the dog is injured, or has to undergo surgery for any reason.
By nature of the condition, it can go undiagnosed for many years potentially, until the dog in question is injured and proves unable to heal their injury naturally. However, as most dogs today or spayed and neutered and because surgical incisions of course break the skin, it is often identified at the time of neutering.
This is of course not relevant to dogs that are left entire to be used for breeding, and poses a problem in that dogs that are affected by the condition may unwittingly be bred from before they are diagnosed.
The Kennel Club and the British Veterinary Association runs a testing scheme for the condition in breeds known to be affected by it, in order to allow dogs to be tested for the condition prior to breeding.
In this article, we will look at Factor VII deficiency in dogs in more detail, including what sort of dogs can develop the condition, how the heredity of the condition works, and how to get dogs of at-risk breeds tested for the markers of the condition. Read on to learn more.
Factor VII deficiency means that Factor VII, an important agent required for blood coagulation, is either missing or not produced in large enough quantities to be effective at clotting the blood and stopping bleeding. Dogs may be only mildly affected by the condition, which will usually mean that they take longer to stop bleeding than normal but this is unlikely to be problematic unless they suffer from a large injury.
However, the condition can be more severe in other dogs, leading to a potentially fatal loss of blood if the skin is broken (or internal bleeding occurs) which can prove fatal, or result in the need for an urgent blood transfusion in order to save the dog’s life.
Factor VII deficiency has been identified in various different breeds of dog worldwide, but when it comes to UK dog populations, only a couple of breeds have been identified as possessing the gene mutation that can lead to the condition at high enough incidence rates as to warrant testing.
Testing is advisable for the Alaskan Klee Kai, the beagle and the Scottish deerhound, and the addition of the Beagle to recommended breeds for testing is a relatively recent thing, having only come into play with the UK Kennel Club in 2015.
It is also important to bear in mind that mixed breed dogs containing partial ancestry from any of the affected breeds can potentially inherit the condition too.
Factor VII deficiency is an autosomal recessive hereditary condition, which means that the status of any given dog where the condition is concerned depends on the combination of genes that they inherit from the parent dogs.
Dogs are assigned one of three statuses for the condition: clear, carrier or affected. Clear dogs do not have any form of the gene mutation that causes the condition, and so will not be affected by it nor can pass it on to their offspring. Carriers of an autosomal recessive health condition will not be affected by the condition themselves, but will be able to pass it on to their offspring.
Affected dogs are both themselves affected by the condition and can of course pass it on.
In terms of how the disease is passed on through the breed line, different combinations of status in the parent dogs lead to different results in their offspring.
A simple DNA test is all that is required to return a result on the status of your own dog, and this can be performed with a DNA sample submitted to one of The Kennel Club’s approved laboratories, who will return a result of your dog’s status as either clear, carrier or affected.