- MWDs or other CWDs operating in a deployed environment may or may not have their blood type identified prior to deployment. Identification of a canine’s blood type during deployment and prior to transfusion is always recommended but might not be possible unless commercially available blood typing kits (See Figure 2) are fielded at a Role 2 or Role 3 Veterinary Facilities. For reasons explained below, naïve canines that have never received a prior blood product transfusion can safely receive blood transfusions for a short period of time prior to both typing and cross-matching, if necessary.
- The most commonly tested and reported blood type in canines is DEA 1. In addition to DEA 1, there are 12 other DEA blood types that are based on antigenic surface markers of the canine erythrocyte.22 Generally speaking, only the presence of the DEA 1 antigen has historically resulted in clinically relevant transfusion reactions in dogs. As a result, most commercially available blood typing kits screen specifically for the presence (DEA 1 positive) or absence (DEA 1 negative) of the DEA 1 antigen. MWDs and other operational canines will therefore have a blood type reported as DEA 1(or with the older naming convention DEA 1.1) positive or negative if they have been previously blood typed. Although DEAs could theoretically cause transfusion reactions, there is no evidence in the veterinary literature to support routine screening of these antigens.
- It is important to note that canines do not typically have naturally circulating alloantibodies to the DEA 1 antigen. Therefore, it is possible to transfuse non-typed canine blood products into another MWD and not experience a transfusion reaction – giving rise to the adage that “the first transfusion is free.” In practice, the veterinary personnel and other HCPs in theater can emergently provide blood products to MWDs without knowing the blood type of the MWD during the first 72 to 96 hours of care. However, dogs will develop alloantibodies to the DEA antigens 5 to 7 days post-transfusion and should be cross-matched 72 hours after receiving the first transfusion.
- Popular, commercially available blood typing kits include point-of-care kits made by RapidVet® and Alvedia (Figure 2). Both kits are simple, inexpensive, and easy-to-use. However, the user should be advised that erythrocyte auto-agglutination can affect interpretation of the RapidVet® test kit. If erythrocyte agglutination is present, a cell washing step is required prior to using the typing cards. The Alvedia test kit is unaffected by cell agglutination due to its patented membrane technology embedded in the testing cartridges.