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Evaluating crossmatch incompatibility to increase safety of blood transfusion in cats and dogs


To compare different ways of performing a “crossmatch” before blood transfusion. Crossmatching is a test that might increase safety of blood transfusion prior to transfusion in both first-time transfusion patients and previously transfused patients.

Study Information:

Blood transfusion is an essential part of therapy for critical small animal patients. Although life-saving for many patients, blood transfusion is not without risk.

Crossmatching (CM) is a method used to test blood compatibility (matching) between a blood donor and an intended recipient, prior to blood transfusion. Giving a compatible or matched transfusion helps risk of transfusion reactions. In simple terms, the CM mimics a transfusion by mixing blood samples from the blood donor and the patient, and watching for abnormalities in the blood. Essentially, this process mimics the transfusion outside of the patient, prior to giving a transfusion.

Currently, CM is usually only performed in patients with a history of previous transfusion as they are considered to be at higher risk for blood transfusion incompatibilities or mismatching. However, new information suggests that any patient in need of blood transfusion could benefit from this test regardless of if they previously had a blood transfusion or not.

CM is performed by sending a sample to a reference laboratory, therefore results are often immediately available for patients needing emergency transfusion. New point-of-care CM kits are available for cats and dogs to rapidly provide CM results using simple technology and alleviate these concerns. However, the accuracy of such kits is not known and therefore needs to be explored.

Study Aims:

This study aims to answer the following questions:

  1. What rate of CM incompatibilities exists in dogs and cats without a previous history of blood transfusion?
  2. Are the new point-of-care CM test kits accurate when compared to the laboratory methods?

This study has the potential to identify if all patients would benefit from a CM prior to any transfusion. Additionally, if the point-of-care CM kits are as accurate as laboratory methods, this will make CM more accessible to patients in all types of veterinary hospitals, increasing safety of blood transfusions.

Inclusion criteria:  

  • Confirmed diagnosis of anemia
  • Blood cell transfusion therapy has been recommended

Samples required:  

  • 5ml blood

Client Compensation:              

  • New patients – no cost
  • Previously transfused patients – required to pay for crossmatching but additional testing will be performed at no cost         


  • Dr. Shauna Blois (PI)


Dr. Shauna Blois, Telephone (519) 823-8830; Email:

Vicky Sabine (PhD), Clinical Research Coordinator

Funded by OVC Pet Trust.

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