HEMOPHILIA A

WHAT IS IT?

• Hemophilia A is the most common severe inherited coagulation disorder in animals and human beings.
• In dogs, as in other species, the disease arises as the result of spontaneous mutation.
• Once hemophilia appears in a family, the defect can then be transmitted through many generations.

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• The gene for Factor VIII is carried on the X chromosome and the presence of one normal gene is sufficient to prevent hemophilia.

THAT MEANS....

• Males having one normal gene and females having two normal genes for Factor VIII are clear of the Hemophilia A trait and will not transmit this defect to offspring.
• Females having one normal and one abnormal gene are asymptomatic carriers and will transmit the abnormal gene, on average, to one half of their sons and one half of their daughters.

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• Hemophilia is most commonly propagated within a line when asymptomatic carrier females are bred to normal males. The male puppies produced from this mating with each have a 50:50 chance of being affected with hemophilia, and the females will each have a 50:50 chance of being a carrier.

CLINICAL SIGNS

• Hemophiliacs may bleed spontaneously into joints or muscles resulting in lameness and swelling.
• Severe, often fatal hemorrhage can occur into the chest or abdominal cavity.
• Hematoma
• Excessive hemorrhage
• Early death

DIAGNOSIS

• Coagulation assays
• The APTT (Activated Partial Thromboplastin Time) is a screening test for coagulation defects

TREATMENT

• Frequent intravenous injections of recombinant factor VIII