Factor VIII Deficiency, Hemophilia A

Affected puppies may bleed abnormally when teething. You may notice extensive bruising or bleeding that does not stop following a traumatic event. If spontaneous bleeding occurs, you may notice that your dog has swollen joints, difficulty breathing, and/or a pendulous abdomen.

This disease is typically diagnosed in puppies or young adults when they are spayed or neutered and have a problem with clotting. However, it can be diagnosed at any age.

Genetic or laboratory tests are performed to diagnose this condition.

Currently, treatment for Hemophilia A focuses on prevention, vigilant monitoring, and quick treatment of spontaneous bleeds. Dogs with Hemophilia A are at great risk for uncontrollable bleeding during surgical procedures: your veterinarian should be informed so that appropriate blood products are at hand in case a transfusion is required. There is no definitive cure, though scientists have made progress correcting Hemophilia A with protein replacement and gene therapy in a laboratory setting.

Talk to your vet about your dog’s genetic result, as it could impact upcoming surgeries or procedures.

Be cautious with activities that could lead to injury, like rough play at dog parks or off-leash hikes.

To help stop minor bleeding, such as from a broken nail, keep basic first-aid supplies on hand, including bandaging material and styptic powder.

If your dog is injured, apply gentle pressure with gauze or a clean cloth to the wound. Keep your vet’s contact information handy in case the bleeding doesn’t stop within a few minutes.

This variant was first identified in Boxers.

Penetrance: Factor VIII deficiency has a sex-linked recessive inheritance pattern, which means that the gene is on the X chromosome. Females have two X chromosomes and must inherit two abnormal copies to be affected with this disease. Males have only one X chromosome and either have a normal copy of the gene or the mutation. If they have the mutation, they will have abnormal clotting.

Gene

F8 Exon 10

Inheritance type

X-linked recessive

Clinical category

Hematologic

Citations

1. Christopherson et al 2014

• Boxer