Canine Scott Syndrome

Canine Scott Syndrome (CSS) is a bleeding disorder caused by a hereditary defect affecting blood platelets, which are important in the blood clotting process. This means that clots form more slowly at a site of bleeding.

Found in

1 in 330 dogs

in our testing

Key Signs

Excessive bleeding after surgery, Nosebleeds, Nontraumatic hemorrhage

Age of Onset

At birth

Present at birth


Autosomal Recessive

For autosomal recessive disorders, dogs with two copies of the variant are at risk of developing the condition. Dogs with one copy of the variant are considered carriers and are usually not at risk of developing the disorder. However, carriers of some complex variants grouped in this category may be associated with a low risk of developing the disorder. Individuals with one or two copies may pass the disorder-associated variant to their puppies if bred.

Likelihood of the Condition

Moderate-high likelihood

At risk dogs are likely to show signs of this disease in their lifetime.

What to Do

Here’s how to care for a dog with CSS

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 CSS

The most common clinical sign of the disease is postoperative bruising and hematoma formation at surgical sites. The symptoms are usually mild but life-threatening bleeding following surgery has been reported. Nonsurgical bleeds may also occur and include potentially recurrent episodes of epistaxis (nosebleeds) and hemorrhage into joints or soft tissues. Petechiae of the gums has not been reported as a symptom. The disease is caused by a defect in the transportation of phosphatidylserine to the surface of activated platelets. There is no cure.

Treatment with blood or platelet transfusions is performed as necessary.

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 recessive meaning that two copies of the mutation are needed for disease signs to develop. A carrier dog with one copy of the CSS mutation can be safely bred with a clear dog with no copies of the CSS mutation. About half of the puppies will have one copy (carriers) and half will have no copies of the CSS mutation. Puppies in a litter which is expected to contain carriers should be tested prior to breeding. Carrier to carrier matings are not advised as the resulting litter may contain affected puppies. Please note: It is possible that disease signs similar to the ones caused by the CSS mutation could develop due to a different genetic or clinical cause.

Technical Details

Gene ANO6
Variant G>A
Chromosome 27
Coordinate 8,912,219

All coordinates reference CanFam3.1

References & Credit

Credit to our scientific colleagues:

Brooks, M. B., Catalfamo, J. L., Macnguyen, R., Tim, D., Fancher, S., & Mccardle, J. A. (2015). A TMEM16F point mutation causes an absence of canine platelet TMEM16F and ineffective activation and death-induced phospholipid scrambling. Journal of Thrombosis and Haemostasis, 13(12), 2240–2252. View the article

Jandrey, K. E., Norris, J. W., Tucker, M., & Brooks, M. B. (2012). Clinical Characterization of Canine Platelet Procoagulant Deficiency (Scott Syndrome). Journal of Veterinary Internal Medicine. View the article