Bernard-Soulier Syndrome, BSS


Dogs affected by Bernard-Soulier Syndrome (BSS) have increased bleeding tendencies. The GP9 gene encodes a subunit of a platelet surface membrane glycoprotein complex; this functions as a receptor for von Willebrand factor (VWF), which initiates the maintenance of blood clotting (hemostasis) after injury.

  • Signs and symptoms

    Signs of this condition include nose bleeds (epistaxis), gingival bleeding, blood in the urine (hematuria), or bleeding after mating. Affected dogs will suffer bleeding tendencies throughout their entire life.

    The typical age at presentation for the first evidence of a bleeding problem is between two to four years of age. However, bleeding may be minimal unless a significant trauma occurs.

    Uncover health risks with Embark

    Embark Breed + Health Test

    Original price:


    Sale price:



    Embark for Breeders Dog DNA Test

    $129 - $159


  • Diagnosis

    Dogs with BSS show fluctuating changes on complete blood counts (CBCs) which may include enlarged platelets in low numbers, also called macrothrombocytopenia. The most common sign is abnormally large blood clots that result in bruising and bumps beneath the skin (hematoma formation) after they have blood drawn. Genetic testing may reduce the incidence of misdiagnosis as another platelet disorder such as immune-mediated thrombocytopenia (IMTP).

  • Treatment

    Currently, treatment for BSS focuses on prevention of bleeding episodes, vigilant monitoring, and quick treatment of spontaneous bleeds. Dogs with BSS are at an increased risk for uncontrollable bleeding during surgical procedures. Veterinarians should be informed so that appropriate blood products are on hand in case a transfusion is required for affected dogs. Vets might be cautious in prescribing drugs that have an inhibitory effect on platelet aggregation.

  • What to do if your dog is at risk


    • Prevention is key! Minimizing the risk of trauma and informing your veterinarian so that surgeries can be carefully planned are the best ways to prevent a catastrophic outcome.
    • BSS may be life-threatening in certain situations. Be aware of the location of the nearest emergency veterinary hospital, and please seek veterinary care immediately.
    • Follow all recommendations from your veterinarian regarding medications that may impact platelet function.

  • Genetic Information

    This variant was first described in Cocker Spaniels.

    Bernard-Soulier Syndrome is recessive, that is, a dog requires two copies of the variant to show signs of the disease from this variant.

    Gene names:

    GP9 ‐ chr

    Inheritance type:


  • Breeds affected

    This health condition affects the following breeds

Learn about your dog’s unique genetic health

Dog owners

Breed identification, health and trait insights, personalized care recommendations, and the world’s first canine relative finder—all in one leading dog DNA test.

Learn about the report for dog owners
Shop the test
Breeding programs

Embark’s test for breeding programs is one comprehensive DNA test designed with your needs in mind.

Learn about the report for breeders
Shop the test