VetGen - The leader in veterinary genetic disease research and genetic disease detection services for purebred animals

Breeds Serviced

  • Havana Silk Dog
  • Havanese
  • German Shepherd Dog

Hemophilia A - Coagulation Factor VIII deficiency

FVIII deficiency, or Hemophilia A as it is more commonly known as is a sex-linked recessive trait. As such, most affected animals are males, because with a single X chromosome they only need inherite one copy of the mutation from the mother's X chromosome to be affected. For a female to be affected, she must inherit a mutated X chromosome from each parent.

The disease is a clotting disorder which leads to excessive bleeding in affected animals. Depending on the specific mutation, this may vary from a mild disease to extremely severe bleeding episodes. Males that inherit a defective gene on their X chromosome will be affected. Females with two defective copies will be affected, while those with a single copy will exhibit no symptoms but be carriers of the disease. The mutation responsible for this disease in the Havanese breed has been identified by our colleagues at Laboklin and their collaborators, and can now be offered at Vetgen.

Result types: Males- Clear or Affected Females- Clear, Carrier, Affected


Normal females can be bred to any male. Normal males should be bred only to normal females.
Dog will never develop the disease.


Female is a carrier of one mutant X chromosome, but will never develop the disease.
Only female can be a carrier of the disease.


Affected males should be bred only to normal females. Affected females should not be bred.
Affected males and females will develop the disease.