Back

Hemophilia B (Rhodesian Ridgeback Type)

Hemophilia B (Rhodesian Ridgeback Type) is an inherited bleeding disorder in dogs caused by a deficiency of coagulation factor IX, crucial for normal blood clotting.

Affected Genes: F9

Inheritance: X-Linked Recessive

Variant(canFam6):
chrX:95358200: G>A

Breed: Rhodesian Ridgeback

General Information: Hemophilia B (Rhodesian Ridgeback Type) is a genetic bleeding disorder resulting from a deficiency in coagulation factor IX, an essential protein for normal blood clotting. The severity of this disorder can vary, with more severely affected dogs experiencing severe bleeding after minor surgeries or trauma and occasionally spontaneous bleeding. These dogs may bruise easily, have frequent nosebleeds, bleed from the mouth when losing juvenile teeth, and show signs of lameness or stiffness if bleeding occurs in the joints or muscles. Mildly affected dogs may present with easy and excessive bruising and frequent nosebleeds. There is a significant risk of prolonged bleeding after surgery or trauma, which can sometimes be severe enough to cause death. Veterinarians performing surgery on affected dogs should have access to banked blood for transfusions. Despite the increased blood clotting times, most dogs with Hemophilia B can have a normal lifespan with appropriate management.

How to Read Your Dog's Test Results for this Genetic Variant:

Two Variants Detected: Dog Likely Affected

One Variant Detected: Dog Unlikely Affected

No Variants Detected: No Effect

Gene / Testing Information: Genetic testing for Hemophilia B (Rhodesian Ridgeback Type) involves screening for mutations in the F9 gene to determine carrier status. This disorder is inherited in an X-linked recessive manner, meaning that female dogs must inherit two copies of the mutated gene (one from each parent) to develop the disease, while male dogs only need one copy from their mother to be affected. Therefore, male dogs are more commonly symptomatic. Each male pup born to a carrier female has a 50% chance of inheriting the disease. Genetic testing is crucial for responsible breeding practices, as female carriers typically do not show symptoms. To avoid producing affected puppies and eliminate the mutation from breeding lines, it is essential not to breed two known carriers. Dogs that are not carriers do not pose a risk of producing affected offspring.

References:
Mischke R, Kühnlein P, Kehl A, Langbein-Detsch I, Steudle F, Schmid A, Dandekar T, Czwalinna A, Müller E. G244E in the canine factor IX gene leads to severe haemophilia B in Rhodesian Ridgebacks. Vet J. 2011 187(1):113-118.