Blood is made up of cells and a liquid. The cellular portion comprises approximately 35-45% of the total volume. When the cellular percentage drops below 10-12% a transfusion is considered. Although transfusions can be life saving there are some negative aspects to consider as well.
Animal blood can be typed and cross matched if repeated transfusions are needed to reduce the risk of an allergic reaction. In many animal hospitals across the country there is often a hospital donor cat and/or dog that can be called upon to donate blood if needed. For those hospitals that do not have a donor readily available there is a blood bank service available.
In most cases it is best to try to stabilize the pet’s blood system if at all possible and thus avoid a transfusion. As the concentration of cells drops in the blood stream there is an automatic stimulus for the bone marrow to produce more cells. If this change happens slowly enough the cells can be replaced without needing a transfusion. If there is a rapid blood loss there may not be enough time for the bone marrow to respond adequately. If a transfusion is given the stimulus to replace the cells is lost temporarily. A transfusion usually will last for approximately 30 days.
There are certain diseases and parasites that can be transmitted in a transfusion. Both Felv and FIV can be carried in a transfusion. The parasite hemobartenella can also be transfused to a new host in this manner. The most common problem with transfusions is an allergic reaction and not the transmission of a disease or parasite.