Blood groups are dependent on the availability or absence of particular antigens (proteins and sugars) on the membrane of red blood cells. In typical cases, dogs don’t produce antibodies against their own cellular antigens or those of other canines, unless there has been a previous transfusion. In species such as cats and humans, antibodies from a particular individual can have adverse effect on the antigens of another individual within the same species, even if there hasn’t been previous exposure.
Dogs have several different blood groups, and their red blood cells may have any mixture of these, as every blood group is autonomously hereditary. The most significant dog blood group is known as Dog Erythrocyte Antigen (DEA) 1.1. Blood donors and recipients are usually typed prior to a transfusion. Roughly 40% of dogs are positive for DEA 1.1, implying that their red blood cells contain the antigen. By picking donor animals that don’t have DEA 1.1, or those that match the recipient, the threat of sensitizing the recipient can be lessened. If a DEA 1.1-negative dog is given DEA 1.1-positive blood, it might build up antibodies that quickly devastate the red blood cells if a subsequent DEA 1.1-positive transfusion is given. A dog that is DEA 1.1-positive can be given either positive or negative blood.
The blood group of an animal is dependent on the reaction of a little sample of blood to specific antibodies. Dogs are characteristically typed only for the most powerful antigen, DEA 1.1. Apart from DEA 1.1, there are 12 other blood group systems. Any antigen can create a reaction if those cells are given to an already sensitized dog, though the chances of that are low. A dog that has received blood before may develop antibodies to the blood group antigens that their own red blood cells contain. Detecting these antibodies is possible if the red blood cells from a possible donor are tested with plasma from the individual receiving the blood. This process is called a major cross-match. If clumping of the cells takes place, the recipient is deemed to have antibodies that might annihilate the donated red blood cells. That means that the donor is incompatible and the blood cannot be used.
In majority of cases, a transfusion is necessary if there is an emergency, possibily due to excessive bleeding or abrupt destruction of red blood cells due to illness. Treatment of anaemia may also require a blood transfusion. Animals that suffer from blood clotting disorders usually need frequent transfusions of whole blood, red blood cells, plasma, or platelets. The greatest danger from transfusions is severe damage to red blood cells, usually as a result of a previously produced antibody to DEA 1.1, or to another antigen. This is quite uncommon, though. A more widespread dilemma in dogs that are multiple transfusion recipients is deferred destruction of the red blood cells, resulting from antibodies to some minor blood group antigens.
Other difficulties related to transfusions comprise infection from tainted blood, a decline in blood calcium quantities, and build up of fluid in the lungs due to donating excessive amounts of blood. Skin inflammation, fever, and nausea are just some of the common bodily responses. However, majority of transfusions are safe and successful.