OBJECTIVES

In the half of the past century the AB blood group system of cats was discovered, with two major blood types known as A and B, and a very rare type named AB. Type A and type B are inherited as a simple autosomal mendelian trait with A being dominant over B. About 30% of type A cats have naturally occurring low titre anti-B antibody, and in contrast type B cats invariably have naturally occurring high titre anti-A antibody. The blood type frequency varies geographically and between breeds. The type A is the most common. However, larger variations are observed among purebred with the B type varying from 0-59%. The frequency of feline blood types in the Northern Portugal is unknown, and the risks of unmatched transfusions and neonatal isoerythrolysis within this area may not be estimated. This study may help to estimate the prevalence of feline blood types in this geographical area and to predict the needs of blood typing prior to transfusion and matting.

MATERIALS

One hundred and seventy two cats were sampled for blood typing determinations from Vila Real and Oporto areas. The samples were obtained from the veterinary teaching hospital of the University of Trás-os-Montes e Alto Douro, cat fanciers and veterinary hospitals. One ml of venous blood was collected for tubes containing EDTA. Blood samples were stored at 4°C until blood typing was performed. Blood was typed within 3 days of collection. The samples were typed using a new blood typing kit (ID card "anti-A/anti-B" DiaMed AG®, 1785 Cressier sur Morat, Switzerland). Age, breed, gender and previous diseases from each animal were recorded. All type B cats were tested with anti-A serum and anti-B (Triticum vulgaris lecitin).

RESULTS

From the 172 cats tested 58.1% (100) were females and 41.9% (72) were males. The non-pedigree cats represented 87.2% (150) of the total sample: 7 Siamese crossbred, 132 Domestic Shorthair, and 11 Domestic Longhair; 95.3% (143) were type A and 4.6% (7) were type B (five Domestic Shorthair females, one Domestic Longhair male and one Siamese crossbred female. The pedigree cats represented 12.8% (22): 4 Persian and 18 Siamese, among them no type B cats were found. In our study cats with AB blood type were not found.

CONCLUSION

The results from this study showed that type B animals frequency among non-pedigree animals was 4.6%. The absence of type B animals among purebred cats could be explained by the low number of pedigree cats and breeds tested, furthermore Siamese cats have been previously reported to be 100% type A and only 4 Persian cats were available in our study.

These results corroborate that the risk of an uncrossmatched transfusion reaction is sufficiently high in common breeds to warrant prior blood typing or crossmatching.