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Factor XI Deficiency

Factor XI Deficiency is a hereditary disorder that impacts blood clotting. The disease usually causes a mild, spontaneous bleeding disorder but more severe bleeding may occur following surgery. Many dogs that are at risk will not show any signs of disease.

Key Signs

Bloody urine, Gingival bleeding, Nose bleed, Severe bleeding after surgery or trauma

Age of Onset

At birth

Present at birth


Autosomal Dominant

For autosomal dominant disorders, dogs with one or two copies of the disease variant are at risk of developing the condition. Inheriting two copies of the risk variant may make the risk higher or the condition more severe. They may produce puppies affected with the disorder if bred.

Likelihood of the Condition

Moderate likelihood

At risk dogs may show signs of this disease in their lifetime, although some will not develop the condition due to absence of additional risk factors.

What to Do

Here’s how to care for a dog with Factor XI Deficiency

Partner with your veterinarian to make a plan regarding your dog’s well-being, including any insights provided through genetic testing. If your pet is at risk or is showing signs of this disorder, then the first step is to speak with your veterinarian.

For Veterinarians

Here’s what a vet needs to know about Factor XI Deficiency

The disorder is caused by the deficiency of the intrinsic clotting factor XI which leads to abnormally slow clot formation at the site of vascular injury. In most cases, the disorder causes mild, spontaneous bleeding which may presents as hematuria (blood in the urine), gingival bleeding, or epistaxis (bleeding from the nose). Many affected dogs may also remain asymptomatic. The disorder can sometimes cause severe, life-threatening bleeding 12 to 24 hours after surgical intervention. Excessive bleeding may also occur after trauma.

Affected dogs should be monitored closely for excessive and prolonged bleeding during and after any required surgical procedures or after any trauma. Fresh-frozen plasma transfusions should be provided as necessary to ensure proper clotting if other means are unsuccessful.

For Breeders

Planning to breed a dog with this genetic variant?

There are many responsibilities to consider when breeding dogs. Regardless of test results it is important that your dog is in good general health and that you are in a position to care for the puppies if new responsible owners are not found. For first time or novice breeders, advice can be found at most kennel club websites.

This disease is autosomal dominant meaning that one copy of the mutation is needed for disease signs to occur. Use of dogs with one or two copies of the disease mutation is not advised, as there is a risk that the resulting litter will contain affected puppies. For example if a dog with one copy of the Factor XI Deficiency mutation is bred with a clear dog with no copies of the Factor XI Deficiency mutation, about half of the puppies will have one copy and half will have no copies of the Factor XI Deficiency mutation. Please note: It is possible that disease signs similar to the ones caused by the Factor XI Deficiency mutation could develop due to a different genetic or clinical cause.

Technical Details

Gene FXI
Variant Insertion
Chromosome 16
Coordinate Start 44,477,344
Coordinate End 44,477,343

All coordinates reference CanFam3.1

References & Credit

Credit to our scientific colleagues:

Tcherneva, E. (2007). Molecular base of coagulation factor XI deficiency in Kerry Blue Terrier. Bulgarian Journal of Veterinary Medicine, 10(4), 247–255. Retrieved from View the article