Naturally occurring antibodies against canine red blood cell antigens in cats and feline red blood cell antigens in dogs.

Xenotransfusion of canine blood to cats may be a life-saving procedure when treating an acute anaemic syndrome and compatible feline blood cannot be obtained. Published evidence in a limited number of cases dating from the 1960s indicates that cats do not appear to have naturally occurring antibodies against canine red blood cell antigens. In fact, compatibility tests before the first transfusion did not demonstrate evidence of agglutination or haemolysis of canine erythrocytes in feline serum, and no severe acute adverse reactions have been reported in cats receiving a single transfusion with canine blood. Severe acute reactions not reported so far cannot, however, be excluded and we decided to perform a pilot study to evaluate the presence of naturally occurring antibodies against canine red blood cell antigens in cats and vice versa. Surplus material from diagnostic samples (blood EDTA and blood serum samples) of 13 cats and 24 dogs was used to perform test-tube major and minor cross-match tests (at 37°C, 4°C and room temperature [RT]) and blood typing, after obtaining the informed consent from owners. Hemolysis, macro- and microagglutination were investigated in each test tube and were considered markers of a positive matching. Blood from each cat was tested with blood from 2–6 different dogs for a total of 49 major and minor crossmatchings, each one performed at the three different temperatures of incubation. Thirty-eight overall major cross-matchings proved positive at 37°C, 33 at RT and 39 at 4°C respectively. The minor cross-matching was positive in all but two tests performed at 37°C. No cat tested totally negative (37°C, 4°C, RT) at both major and minor cross-matching procedures performed towards any single dog. Ten cats experienced positive major and minor cross-matching at 37°C, RT and 4°C towards 1–3 different dogs. Five cats were positive in the major cross-match, at least at 37°C, towards 1–3 different dogs. Seven cats obtained a positive major cross-match at RT and/or at 4°C towards 1–5 dogs. Only two cats tested completely negative at 37°C, RT and 4°C, in one out of the 4 different major cross-matchings performed. In conclusion, naturally occurring antibodies against canine red blood cell antigens appear to be frequently detected in cats as well as those against feline red blood cell antigens in dogs. Xenotransfusion of canine blood to cats should only be performed after the selection of a compatible donor by means of at least a negative major cross-match test result.