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

Breeds Serviced

  • Airdale Terrier
  • Bull Terrier
  • Cairn Terrier
  • Deutsch Drathaar
  • German Wirehaired Pointer
  • Lhasa Apso
  • Rhodesian Ridgeback

Hem B- Coagulation Factor IX Deficiency

Hemophilia B is often a severe bleeding disorder caused by a deficiency of coagulation factor IX resulting in a severely affected blood clotting process. In response to an injury that causes bleeding, affected dogs fail to activate the coagulation process and experience uncontrollable breeding problems. The disease occurs in many different breeds and in mixed breed dogs as well.

Hemophilia is an X-linked recessive disorder so the disease only occurs when the animal has two copies of the bad gene. It is one of the few sex-linked traits in dogs. Males have 1 X chromosome from their mother, and 1 Y chromosome from their father, which carries little information other than maleness. Females have 2 X chromosomes, 1 each from their mother and father. So, if a mother who is a carrier for a harmful recessive gene ( Xx ) passes the recessive gene (x ) to her daughter, the daughter ( Xx ) will be an unaffected carrier or show less severe involvement, but her sons who receive that gene ( Yx ) will be affected. Even if only midly affected, Xx - females are carriers of the disorder and should not be bred.


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.