Hemophilia A (Factor VIII Deficiency) and Hemophilia B (Factor IX Deficiency) in Dogs

Hemophilia is a type of blood disorder in which the blood is unable to clot properly. It is an uncommon inherited trait that affects mostly male dogs. Mild hemophilia might never be detected; more severe cases have problems such as bleeding from the gums, nose bleeds, and heavy bruising, all of which are usually discovered when the dogs are just pups. There is no cure for the disorder, though even minor injuries in severely affected dogs may require intervention to prevent significant blood loss.


Coagulation (blood clotting) is a defensive process that occurs as a sequence of events designed to minimize blood loss once vessels have been breached. Certain proteins in the blood, known as clotting factors, have a critical role in the coagulation process. When one or more fundamental elements of the sequence (such as clotting factors) are in shorter supply than normal, the ability of the blood to clot is compromised — sometimes mildly, other times severely. With all defects of coagulation, the consequences can be life threatening.

Hemophilia is relatively rare in dogs and can occur in two forms. Hemophilia A involves an inherited deficiency of clotting factor VIII; the severity is variable depending on how much factor VIII activity is present. Hemophilia B is an inherited deficiency in clotting factor IX; it is even less common and almost always severe.

Symptoms and Identification

Mildly affected dogs may experience excessive bleeding only during surgery or may live an entire lifetime with the disease undetected. Severely affected dogs usually present as pups with uncontrollable bleeding from their gums (after losing puppy teeth, for example) or spontaneous bleeding from their noses, gastrointestinal tracts, or under their skin. Bleeding into joints, as sometimes occurs with active pups, can also occur.

More uncommon signs may include difficulty breathing (from bleeding into the airways or lungs), paralysis (from bleeding in the spinal cord), and sudden death due to massive blood loss following simple trauma.

Once a clotting disease is suspected, diagnosis is achieved through blood testing to determine the degrees of clotting dysfunction and clotting factor deficiency. Upon diagnosis, the affected dog’s parents and siblings should be evaluated as well.

Affected Breeds

The German Shepherd is the breed most typically affected. But any breed, even mixes, can be affected.


There is no cure for this disorder. Periodic blood transfusions (or transfusions with plasma or other blood products that supply clotting factors), however, may be required following trauma or simple bleeding. Blood products may also be administered before and after any necessary surgical procedure to help control bleeding.


The ideal method of prevention involves careful screening of dogs intended for breeding.

This article was reviewed by a Veterinarian.

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