"The major crossmatch tests for alloantibodies in the recipient's plasma
against donor cells. A major crossmatch incompatibility is of greatest importance
because it predicts that the transfused donor cells will be attacked by the
patient's plasma, thereby causing a potentially life-threatening acute
hemolytic transfusion reaction."
- Urs Giger, PD, Dr.med.vet.,MS, FVH; Diplomate, ACVIM and ECVIM
Until now, performing a crossmatch was confusing, laborious, and time-consuming, often in an emergency situation. New generation crossmatch tests that utilize gel tube technology are available from DMS. Designed for use with either canine or feline patients, these tests are simple to use, quick to run, and easy to interpret.
In light of the recent discovery of new red blood cell antigens in dogs and cats, performing both blood typing and crossmatch prior to them receiving any blood products is recommended. Crossmatch will reveal incompatibilities between the donor and recipient that will not be evident from blood typing alone.
In all dogs requiring blood products, it is necessary to first determine whether the recipient is DEA 1.1 positive or negative. In most cases, the next step should be a crossmatch. If it can be determined with certainty that a dog has never received a prior transfusion, a crossmatch prior to the first transfusion is not essential.
Tests for determining whether there are also antigens on the red cells for DEA 4, 5, 7 or 9 are not commercially available. New canine blood types are being discovered frequently, including DAL and others. Over 13 have been described. There are no commercially available tests for those either.
If incompatible blood is used with any of these types (X+ blood transfused into an X dog), in even the first transfusion, the viability of the transfused cells will decline rapidly, a second transfusion may be required within 4 to 5 days, and by then antibodies to the incompatible antigen will have formed.
Should a second transfusion ever be needed, determining only that the blood of that donor and the recipient is DEA 1.1 compatible will NOT be sufficient. Antibodies in the recipient’s serum to any other antigens on the red cell of the original donor may have formed. Only a crossmatch will determine if that has occurred.
Cats have naturally occurring antibodies to antigens not on their red cells. Thus cats with type A blood have antibodies to type B antigens and cats with type B blood have antibodies to type A antigens. In this species, a crossmatch should be performed prior to every transfusion. For cats as well, new blood types are being discovered frequently, including MIK and others. Over 12 have been described. Cats that do not have MIK antigens on their red cells will have MIK antibodies before any transfusion. Thus determining the A or B blood type for compatibility is NOT sufficient. Only a crossmatch will uncover the problem.