Canine platelet storage improved or prevented bleeding in 70% of cases

By Amara Osei

In a single-center clinical evaluation of 24 dogs at Washington State University’s Veterinary Teaching Hospital, refrigerated platelet concentrates improved bleeding outcomes or helped prevent bleeding complications in 70% of cases, with no transfusion reactions documented.

The study found that processed, refrigerated canine platelets remained effective for treating or preventing bleeding for up to three weeks. That storage life far exceeds the few days typically available with traditional platelet products stored at room temperature.

What did the 24-dog evaluation test?

Platelets are specialized blood cells that form clots. Transfusions can be one of the few treatment options for dogs with severe bleeding or a high risk of hemorrhage from immune-mediated thrombocytopenia, cancer, severe inflammation, trauma, or other conditions.

Haines’s team evaluated cold-stored platelet concentrates in 24 dogs cared for at the WSU Veterinary Teaching Hospital. The products were administered for:

• treatment of active bleeding;
• support during surgeries;
• support during diagnostic procedures that posed substantial bleeding risk; and
• management of severe hemorrhage.

The products improved bleeding outcomes or helped prevent bleeding complications in 70% of cases, and investigators documented no transfusion reactions. Haines and colleagues described the results as the first clinical evidence that cold-stored platelets can be used effectively in dogs.

The report builds on Haines’s earlier work, which showed that refrigerated platelets could remain functional in storage for up to three weeks. Those earlier findings had not tested the products in clinical patients, leaving their effectiveness during bleeding unresolved. The new evaluation directly addressed that gap.

For decades, veterinary clinicians assumed that platelets lost effectiveness after refrigeration. As a result, blood banks relied on products that stayed viable for only a handful of days and required continuous agitation at room temperature.

“It is hard to overstate how important the ability to transfuse platelets is,” Haines said. “Many of us have seen patients die from bleeding complications because there was simply nothing we could offer them. We went from having essentially nothing available to now having a really viable product that we can use.”

The findings appeared in the 2026 Journal of Veterinary Internal Medicine as Shannon A Monaco et al., “The use of cold-stored platelets to provide hemostasis in dogs with thrombocytopenia,” DOI 10.1093/jvimsj/aalag262.

What changes at the exam table?

For companion animals, the practical implication is that a dog with life-threatening bleeding may have a clinically evaluated platelet option when a veterinary hospital or blood bank can supply one. The finding does not yet define a universal transfusion protocol, but it expands access beyond products usable for only a few days.

Veterinarians still need to determine optimal dosing and how to measure effectiveness in each dog; the study did not settle either question. The products also supported several bleeding-related uses in the same evaluation, rather than a single indication.

What does this mean for food animals and public health?

Food animals: The evaluation included only dogs and provides no efficacy, dosing, or storage findings for food-producing species. Extending the 70% result beyond dogs would require separate evidence.

Public health: Haines said cold-stored platelets are less susceptible to harmful bacterial growth, a storage advantage over room-temperature products. The report does not quantify bacterial growth or report infectious outcomes, and it did not evaluate human transfusions or population-level public-health effects. It therefore supports a veterinary storage and clinical-use strategy, not a claim about the human blood supply.

What changes for veterinary blood banks?

Cold storage removes the need for constant agitation and makes the products easier to ship, according to Haines. WSU now routinely maintains a supply of cold-stored platelets at its blood bank, and she has trained veterinarians and blood bank personnel from other institutions on the technique. Interest in the method continues to grow.

The process requires only minor changes to existing blood-processing procedures, which could make production more practical for blood banks and veterinary hospitals. A three-week shelf life also gives these facilities more time to distribute a product that previously had a much shorter inventory window.

What is the regulatory status?

The published report does not state whether canine platelet concentrates have received FDA CVM, EMA, or USDA approval or authorization. WSU’s routine use represents institutional clinical practice, not an agency determination.

What remains unresolved?

Haines wants to determine optimal dosing, develop better ways to measure effectiveness in individual dogs, and evaluate whether cold-stored platelets remain effective beyond three weeks. These are the next questions for a product with lifesaving potential but a limited clinical evidence base.

“It’s not needed often,” Haines said, “but when it is needed, it is the only option. These products can be lifesaving.”

The next studies will determine whether cold-stored platelets remain effective beyond three weeks.