Final answer:
A lethal reaction in cats occurs when mismatched blood types are transfused. This is due to a Type II hypersensitivity reaction where IgG antibodies and complement proteins destroy the donor's red blood cells. Cross-matching is essential to avoid transfusion reactions in cats, especially since a Type B cat receiving Type A blood can result in a severe, often fatal reaction.
Step-by-step explanation:
A lethal reaction in cats can occur when there is a transfusion of mismatched blood types. In blood transfusions, if the blood type of the donor does not match with the recipient's, their body can produce antibodies against the donated red blood cells, leading to a reaction. When antigens from one blood group interact with antibodies from a different group, hemolysis of the red blood cells can occur. This destructive process is mediated by a Type II hypersensitivity reaction, where IgG antibodies and complement proteins result in the lysis of red blood cells, similar to incompatible blood transfusions in humans.
In most cases, to avoid transfusion reactions and potential fatalities, cross matching must be done to ensure the blood types of the donor and recipient are compatible. Crossmatching is a lab test that confirms that the recipient of a blood transfusion has the blood type compatible with the donor blood, avoiding hemolysis and hemolytic anemia. This can be especially important in cats due to their unique blood typing and the presence of blood type antigens unlike humans. Cats have different blood types designated as Type A, Type B, and Type AB. A lethal reaction most commonly occurs when a Type B cat receives Type A blood, as Type B cats have strong anti-A antibodies that can cause a severe reaction. It is crucial to always perform cross-matching before a transfusion, except in emergency situations where type O blood is used.