The use of cold-stored platelets to provide hemostasis in dogs with thrombocytopenia

Platelet transfusion can be lifesaving in dogs with severe thrombocytopenia and hemorrhage, but platelet products are limited by short shelf life and contamination risk. Cold-stored platelets (CSP) may provide a practical alternative, but in vivo hemostatic efficacy in dogs is unknown.

Evaluate the clinical hemostatic efficacy and safety of CSP transfusions in thrombocytopenic dogs.

Twenty-four thrombocytopenic dogs from a veterinary teaching hospital population that received CSP transfusions between March 2022 and October 2024.

Retrospective cohort study. Medical records of dogs receiving platelet concentrate stored at 4 °C for up to 21 days were reviewed. Hemorrhage severity was assessed using a modified Daily Canine Bleeding Assessment Tool (DOGiBAT) score before transfusion and at 1 and 4 h post-transfusion. Primary outcomes included change in bleeding score, clinical response, transfusion reactions, and survival to discharge.

Twenty-four dogs received 27 CSP transfusions. Mean pre-transfusion platelet count was 23 × 103/μL (range, 2-107 × 103/μL) and mean post-transfusion count was 28 × 103/μL (range, 2-100 × 103/μL; P = .84). Mean DOGiBAT score decreased from 3.15 ± 2.4 at baseline to 2.21 ± 2.1 at 4 (mean change, -0.94; P = .002). Clinical improvement occurred in 19 of 27 transfusions (70%). No transfusion reactions were documented. Nineteen of 24 dogs (79%) survived to discharge.

Cold-stored platelets were well-tolerated and associated with decreased bleeding severity in thrombocytopenic dogs, supporting CSP as a practical platelet transfusion option for clinical hemostatic support.