WSU: cold-stored platelets stopped or prevented bleeding in 19 of 27 transfusions in 24 thrombocytopenic dogs

Researchers at Washington State University's College of Veterinary Medicine evaluated cold-stored platelets (CSP) in dogs with low platelet counts. The retrospective cohort study, published in the Journal of Veterinary Internal Medicine, covered 24 thrombocytopenic dogs treated at the WSU Veterinary Teaching Hospital between March 2022 and October 2024 doi.orgJournal of Veterinary Internal Medicinedoi.orgOpen source ↗.

Platelet transfusion can be lifesaving in dogs with severe thrombocytopenia and hemorrhage, but conventional products have a short shelf life and carry a contamination risk. Traditional platelets are stored at room temperature under constant agitation and remain usable for a few days. The authors report that this study provides the first clinical evidence of CSP efficacy in dogs doi.orgJournal of Veterinary Internal Medicinedoi.orgOpen source ↗.

Study design and results

The dogs received 27 transfusions of platelet concentrate stored at 4 °C for up to 21 days. Bleeding severity was scored with a modified Daily Canine Bleeding Assessment Tool (DOGiBAT) before transfusion and at 1 and 4 hours afterwards. The platelets were given to treat active bleeding, to support surgery and diagnostic procedures with significant bleeding risk, or to manage severe hemorrhage doi.orgJournal of Veterinary Internal Medicinedoi.orgOpen source ↗.

The mean DOGiBAT score decreased from 3.15 ± 2.4 at baseline to 2.21 ± 2.1 at 4 hours (mean change −0.94; P = .002). Clinical improvement occurred in 19 of 27 transfusions (70%). Nineteen of the 24 dogs (79%) survived to discharge doi.orgJournal of Veterinary Internal Medicinedoi.orgOpen source ↗.

The mean platelet count was 23 × 10³/μL before transfusion (range 2–107 × 10³/μL) and 28 × 10³/μL after (range 2–100 × 10³/μL); the difference was not significant (P = .84) doi.orgJournal of Veterinary Internal Medicinedoi.orgOpen source ↗.

Safety and practical aspects

No transfusion reactions were documented doi.orgJournal of Veterinary Internal Medicinedoi.orgOpen source ↗. The authors conclude that cold-stored platelets were well tolerated and associated with lower bleeding severity, supporting their use as a practical option for hemostatic support doi.orgJournal of Veterinary Internal Medicinedoi.orgOpen source ↗.

Study lead Jillian Haines, director of the hospital's blood bank, said cold-stored platelets are less susceptible to bacterial growth, do not need constant agitation and can be shipped easily. According to her, the method requires only minor changes to existing blood-processing procedures. The WSU blood bank now routinely keeps a supply, and Haines said she has trained staff from other institutions in the technique.

The study was retrospective and had no control group. Haines said further work is planned on optimal dosing, on measuring effectiveness in individual patients, and on whether the platelets remain effective beyond three weeks of storage.