Genetic basis of Delayed Postoperative Haemorrhage in Scottish Deerhounds - is strongly associated with a missense variant in the SERPINF2 gene (c.605C>T; p.A202V), which codes for alpha-2 antiplasmin, a critical protein for preventing premature breakdown of blood clots (hyperfibrinolysis). Inheritance appears to be autosomal dominant with incomplete penetrance: dogs with one or two copies of the variant are at elevated risk, but not all will necessarily manifest the condition. Dogs with two variant alleles (T/T) have an exceptionally high risk (odds ratio >1,000), while those with one variant allele (C/T) are also at significant risk (odds ratio ~28–40), compared with wild-type (C/C) dogs.
Pathophysiology - DEPOH manifests as unexpected and excessive bleeding or bruising that typically begins 1–4 days post-surgery, due to clots breaking down too early (hyperfibrinolysis). Standard coagulation tests (prothrombin time, partial thromboplastin time, von Willebrand factor, platelets) are normal, making the disorder difficult to diagnose without genetic testing. The alpha-2 antiplasmin deficiency caused by the SERPINF2 mutation disrupts the body’s ability to maintain blood clots, increasing the risk of postoperative bleeding even after routine surgical procedures.
Complications - Dogs with DEPOH risk can develop life-threatening hemorrhages, including open bleeding at surgical sites, excessive and progressive wound bruising, or haemoabdomen. Severe cases may lead to critical anemia, shock, or death if not rapidly recognized and treated. Indiscriminate administration of antifibrinolytic drugs can be costly and may cause adverse effects, highlighting the importance of targeted, pre-operative genetic screening.
Why This Matters to Breeders and Vets - Breeders can use genetic testing to avoid high-risk matings and improve the health and longevity of their lines, as well as inform potential puppy buyers. Veterinarians can use genotyping to identify at-risk dogs before surgery and provide targeted preventive treatment (e.g., antifibrinolytic drugs) to minimize post-operative complications. Understanding genetic status assists in differentiating DEPOH from other bleeding disorders, avoiding unnecessary treatments, and reducing mortality associated with unanticipated hemorrhage.