What is hemophilia?
Hemophilia is a blood clotting disorder that can affect dogs. In the case of hemophilia, it is more precisely secondary hemostasis that is disturbed due to a deficiency in a coagulation factor.
Dogs can be affected by two types of hemophilia: hemophilia type A or hemophilia type B.
Hemophilia type A in dogs
Hemophilia type A is the most common type of hemophilia in dogs. It is a hereditary disease that results from the mutation (sometimes spontaneous but often familial) of the gene coding for factor VIII.This mutation leads to a quantitative or qualitative deficit of this glycoprotein which plays a very important role in the blood coagulation cascade so that dogs carrying the mutation have blood that does not clot properly.
The gene coding for factor VIII is located on the X sex chromosome and the disease is transmitted in a recessive mode so that it is mainly male dogs who express the disease. Females are usually asymptomatic carriers (or show moderate bleeding signs), unless they are homozygous for this mutation, but this case is extremely rare.
Certain breeds are known to be genetically predisposed to this disease. These are the German Shepherd, the German Shorthaired Pointer, the Boxer and the Longhaired Collie.
Type B hemophilia in dogs
Hemophilia type B, also called Christmas disease, is linked to a factor IX deficiency. Like hemophilia type A, it is an inherited genetic disease that is transmitted in a recessive gonosomal fashion.
It therefore more often affects male dogs and certain breeds of predisposed dogs such as the Malamute, the Airedale Terrier, the Rhodesian Ridgeback, the Labrador, the Cocker Spaniel, the Bichon Frisé or even the Shetland Shepherd.
Type B hemophilia is much less common than type A.
How does hemophilia manifest in dogs?
Dogs with hemophilia can be affected more or less severely.
In cases of mild damage, abnormally long bleeding times are observed in the event of trauma or surgery. Some dogs with hemophilia are also diagnosed during surgery when the surgeon observes excessive and abnormally long bleeding.
Dogs affected more severely may show spontaneous bleeding (in the absence of trauma) which can lead to:
- the formation of muscle or joint hematomas (hemarthrosis), accompanied by lameness,
- haemothorax, in other words bleeding in the thoracic cavity, which can lead to the death of the animal.
How is hemophilia diagnosed?
The definite diagnosis of hemophilia A and B requires the determination of coagulation factor VIII and IX in the dog's blood.
Is there a treatment for dogs with hemophilia?
There is no cure for hemophilia.
In the event of significant bleeding, the animal may need to receive a transfusion of fresh blood or fresh plasma. For these reasons, it can be interesting to determine to which blood group the dog belongs in anticipation of a possible transfusion which would take place in emergency.
In dogs with hemophilia, it will be important to prevent bleeding:
- avoiding the risk of injury as much as possible. To do this, it may be necessary to adapt the dog's living environment and avoid "risky" activities,
- by regularly deworming the animal to avoid any digestive bleeding.
Of course, dogs with hemophilia will have to be excluded from breeding so as not to risk transmitting the disease to offspring. It will also be preferable to have a DNA test performed on asymptomatic bitches but related to sick males. If the females are carriers of the mutation, it is also best not to breed them.