Delayed postoperative hemorrhage (DEPOH) - English Springer Spaniel, Welsh Springer Spaniel

In the breeds English Springer Spaniel (ESS) and Welsh Springer Spaniel (WSS), a genetic variant in the SERPINE1 gene has been identified that can lead to a postoperative bleeding tendency with hyperfibrinolysis.

Hyperfibrinolysis refers to a disorder of the blood clotting system in which formed blood clots dissolve too quickly. Normally, fibrinolysis ensures that a blood clot is gradually broken down after wound healing is complete. In hyperfibrinolysis, however, this breakdown process occurs far too early and too intensely. As a result, blood clots can no longer permanently seal the bleeding site, leading to persistent or delayed bleeding.

In affected dogs of these two breeds, the disease often becomes apparent at a young age (from around 7 months), often after surgical procedures or trauma. In addition to delayed and prolonged bleeding after surgery, affected dogs may also suffer from spontaneous bleeding into the abdominal cavity or subcutaneous tissue, as well as hematomas or bloody wound secretions. The affected dogs may appear weak and lethargic, with pale gums and a low pulse.

Standard coagulation tests (PT, PTT, buccal mucosal bleeding time) are usually within normal ranges, which makes it difficult to identify hyperfibrinolysis as the underlying cause of bleeding without genetic testing.

The SERPINE1 gene encodes the protein plasminogen activator inhibitor-1 (PAI-1), which normally regulates the breakdown of blood clots. Due to the genetic variant, no functional PAI-1 is produced in the platelets, which can result in life-threatening bleeding.

Since heterozygous dogs were still found to produce detectable PAI-1 protein and no increased bleeding tendency has been reported in these animals, the inheritance pattern is assumed to be autosomal recessive.