English Springer Spaniel Hyperfibrinolysis

English Springer Spaniel hyperfibrinolysis is an autosomal recessive genetic disorder. The disorder is a result of a mutation in the SERPINE1 gene, which encodes for a protein called PAI-1. PAI-1 is very important in stabilizing blood clots that have formed. Without this protein, blood clots get broken down too quickly and this increases the risk for serious bleeding, particularly after trauma or surgical procedures.

Most veterinarians are not able to diagnose this condition clinically using traditional tests of blood clotting (e.g., platelet count, PT, aPTT), so it can be easily missed when patients are being evaluated for excessive bleeding. Some specialty and academic hospitals can use a test called thromboelastography (TEG) to diagnose hyperfibrinolysis, but this is not the same as a genetic test.

Who gets it?

To date, this mutation has only been identified in English Springer Spaniel dogs. However, it is possible that other related breeds (e.g., Welsh Springer Spaniels) may have the same mutation.

What are the clinical signs?

Hyperfibrinolysis caused by this mutation typically causes excessive bleeding, either after trauma or surgical procedures (e.g., a spay or neuter). The bleeding can often be slow, and if it occurs internally, may not be detected for days or weeks after the traumatic or surgical event. Patients with clinical signs from excessive bleeding can include: pale gums, weakness, fast heart rate, poor pulses, lethargy, and lack of interest in eating.

How is it managed?

Once diagnosed, in the face of excessive bleeding, the disease can be treated with medications that help stabilize blood clots (e.g., aminocaproic acid or tranexamic acid). Dogs with this condition generally do not require lifelong therapy with these medications, but only during periods of excessive bleeding. Knowing that your dog has hyperfibrinolysis is also important for your veterinarian to know before any elective surgical procedures so that medications can be given prophylactically.