Blood transfusion forms a mainstay of the treatment of a variety of illnesses, and is lifesaving. Nonetheless, it is not without its risks and drawbacks. Blood transfusion is a cornerstone in the treatment of canine babesiosis. The development of blood alternatives has received attention in recent times. Blood alternatives offer much of what natural blood does but without many of the associated drawbacks. These include disease transmission, transfusion reactions, poor in vitro and in vivo shelf-life and special storage and administration requirements. One product, Oxyglobin®, is the first commercially available, veterinary-licensed, haemoglobin-based oxygen carrying solution (HBOCS). Although licenced for use in canine babesiosis, this colloidal “Oxygen Bridge” has never been evaluated against the gold standard of therapy, isovolumic packed red blood cell transfusion (pRBCT). This investigation was conducted to evaluate important aspects the equivalence of these two treatments in a field situation of naturally-infected dogs. Given the cost of HBOCS, they are unlikely to be commonly used by the practicing veterinarian in the treatment of canine babesiosis. Nonetheless, similarities in efficacy would bolster the case for and further research into blood substitutes of this and other classes, and may open the way to evaluation of HBOCS for falciparum malarial anaemia, a disease similar in many respects to canine babesiosis. / Dissertation (MMedVet)--University of Pretoria, 2007. / Companion Animal Clinical Studies / unrestricted