Factor XI deficiency and haemophilia C in dogs

Haemophilia is a blood clotting disorder that can affect a wide range of different species of mammals, including dogs and of course, humans. Haemophilia comes in various different types, depending on the reason for the disorder and the effects that it has on the animal in question, and it is a hereditary condition that can be passed on from parents to their offspring.

Various different dog breeds have been identified as having certain types of haemophilia within the bloodlines of a significant enough number of dogs of the breed for it to be considered as a potential risk to the overall health and future health of the breed – and one of these is the Kerry blue terrier.

In the Kerry blue terrier breed, haemophilia C is the variant that has been identified as a hereditary health risk – and this in turn is caused by a deficiency of Factor XI, which is an important component in the body that assists with clotting of the blood, and maintaining coagulation of the blood. However, haemophilia C is still relatively rare both across dogs as a whole and within the Kerry blue terrier breed specifically, and so there is no mandatory health testing protocol in place for the disorder within the Kerry blue terrier breed.

In this article, we will look at factor XI deficiency and haemophilia C in the Kerry blue terrier, and examine how the condition is transmitted, how it affects dogs that inherit factor XI deficiency, and how Kerry blue terrier breeders can find out the status of their breeding stock. Read on to learn more.

What is factor XI deficiency?

Factor XI is one of several clotting factors that are naturally produced by the body, and which helps to coagulate blood so that it is dense enough to support life, as well as being vital in clotting and coagulation for wound healing.

It is a type of blood protein that enables the blood to clot in order to heal a wound and stop bleeding, but in dogs with factor XI deficiency, not enough factor XI is produced, which can lead to bleeding disorders and excessive bleeding if the dog is injured.

Unlike some of the various other clotting factors, factor XI deficiency doesn’t cause the dog’s blood to flow faster when they are wounded, but it does mean that wounds won’t heal properly, and they will often bleed for a long time after a cut or injury occurs. How acutely this affects any given dog with the disorder can vary from case to case.

What is haemophilia C?

Haemophilia is the name given to a group of disorders that affect the body’s ability to coagulate the blood and clot the blood to heal wounds, and there are various different forms of haemophilia, each of which pertains to the clotting factor that is deficient or absent within them.

In humans, haemophilia A and B are the two main variants of the condition, but other less common variants exist too – and the same is true for dogs.

Haemophilia C is the type of haemophilia that is considered to be a risk to the Kerry blue terrier breed, and this is itself caused by a deficiency of factor XI.

In terms of how acutely haemophilia C affects dogs that inherit the affected form of the condition, this can be highly variable, but it is not one of the most acute and potentially serious forms of the condition – although it can still pose life threatening nonetheless.

What sort of dogs are at risk of haemophilia C?

Haemophilia C is one of the rarest forms of haemophilia that can affect dogs, and it can present in dogs of the Kerry blue terrier breed, and also, the Springer spaniel, Great Pyrenees, and Weimaraner dog breeds too.

Haemophilia is often thought of as a disorder that affects males, and some forms of haemophilia don’t affect females (despite being passed down through the matrilineal genes) – but haemophilia C can affect both males and females, and is present from birth in affected dogs.

However, it may not become evident that a dog has inherited the condition until they become injured.

How do dogs inherit haemophilia C?

Haemophilia C is passed from one dog to another by means of autosomal recessive heredity, which means that for a dog to inherit the affected form of the condition, they need to inherit the gene fault that causes factor XI deficiency and so, results in haemophilia from both sides of their bloodline.

Dogs can be either clear, carriers, or affected – and knowing the status of the two parent dogs allows you to predict the status of their puppies.

• Two clear dogs will have clear offspring.
• Two affected dogs will have affected offspring.
• Two carrier dogs will have a litter of 50% carriers, 25% clear, and 25% affected.
• A clear dog and an affected dog will produce a litter of carriers.
• A clear dog and a carrier will produce a litter of 50% clear and 50% carriers.
• A carrier and an affected dog will produce a litter of 50% carriers and 50% affected.

How can you find out the status of any given dog?

When it comes to hereditary health problems that pose a threat to a significant number of dogs of any given breed and for which a test is available to determine the status of dogs of the breed, The Kennel Club mandates pre-breeding health screening protocols for pedigree dogs that will be registered with The Kennel Club.

However, because haemophilia C is still relatively rare, even within the Kerry blue terrier breed, factor XI deficiency and haemophilia C is not one of the conditions for which The Kennel Club mandates tests.

That said, there is a test available, offered by some laboratories including The Center for Animal Genetics, which allows breeders of the Kerry blue terrier to find out the status of any two prospective parents dogs prior to breeding.

Having dogs of the breed tested is advisable if the relatives of any prospective breeding stock have themselves been diagnosed with haemophilia C or factor XI deficiency.