Factor XI Deficiency and Haemophilia C in Dogs: A Complete Guide

Haemophilia, a blood clotting disorder affecting various mammal species including dogs and humans, varies by type and cause. It is hereditary, passed from parent dogs to puppies, impacting their ability to form blood clots and heal wounds properly.

Certain breeds have recorded cases of haemophilia in their bloodlines significant enough to pose health risks. One breed notably affected is the Kerry blue terrier, prone to haemophilia C, caused by a deficiency in Factor XI, a vital blood coagulation protein. Though relatively rare, awareness can help ensure healthier breeding practices.

What is factor XI deficiency?

Factor XI is a natural clotting protein essential for blood coagulation and wound healing. Dogs with factor XI deficiency produce insufficient amounts, leading to prolonged bleeding and delayed wound healing following injury.

Unlike other clotting disorders that might accelerate bleeding, factor XI deficiency slows clot formation, causing wounds to bleed longer. The severity varies, with some dogs showing only mild symptoms unless injured or undergoing surgery.

Understanding haemophilia C in dogs

Haemophilia encompasses a group of inherited disorders impacting blood clotting due to missing or deficient clotting factors. In dogs, haemophilia C specifically involves a shortage of factor XI. While less severe compared to haemophilia A and B, it still can cause life-threatening bleeding episodes.

Dogs with haemophilia C might appear healthy at birth but suffer unexpected bleeding after trauma or surgical operations. Early diagnosis and management empower owners and breeders to mitigate risks effectively.

Breeds at risk and hereditary patterns

Besides the Kerry blue terrier, haemophilia C is found in breeds including the Springer spaniel, Great Pyrenees, and Weimaraner. It affects males and females equally, inherited via an autosomal recessive gene pattern.

To inherit haemophilia C, a dog must receive two copies of the defective gene—one from each parent. Dogs can be classified as clear (no gene), carriers (one gene copy), or affected (two copies). Understanding these categories is crucial for responsible breeding decisions.

• Two clear parents produce clear offspring.
• Two affected parents produce all affected puppies.
• Carriers bred together yield 25% affected, 50% carriers, and 25% clear puppies.
• Clear paired with affected yields 100% carriers.
• Mixed clear and carrier matings yield 50% clear and 50% carriers.
• Carrier and affected matings produce 50% affected and 50% carriers.

Testing and responsible breeding practices

Although haemophilia C is rare, a genetic test for factor XI deficiency exists, offered by specialised laboratories such as The Center for Animal Genetics. Testing breeding stock, especially dogs related to diagnosed cases, supports informed mating choices.

The Kennel Club currently does not mandate testing for factor XI deficiency in Kerry blue terriers, but proactive screening promotes health and reduces hereditary disease prevalence. Raising breeder awareness and emphasising ethical breeding protect the breed's future.

Managing dogs with factor XI deficiency

Dogs with factor XI deficiency can live normal lives when managed with care. Owners should inform their vets if their dog is affected, especially before surgeries or dental work to avoid dangerous bleeding.

Treatment during bleeding episodes may involve transfusions with fresh-frozen plasma or blood products to aid clotting. Veterinary guidance ensures the best outcomes and quality of life for affected dogs.

Conclusion

Factor XI deficiency and haemophilia C, though rare in breeds like the Kerry blue terrier, demand attention for breeding and healthcare. Understanding inheritance, testing breeding animals, and managing affected dogs responsibly helps reduce risks and safeguard their health.

Prospective owners and breeders should seek reputable health screening and collaborate with vets to ensure the well-being of their dogs. Promoting knowledgeable, ethical breeding fosters healthier canine generations.