Blood transfusions are often life-saving procedures. By intravenously introducing new blood into an animal, a vet can compensate for blood that has been lost due to injury, or replace blood cells that have died off due to infection or illness. In cats, however, there are some specific factors that need to be considered before a transfusion is conducted, in order to minimize the potential risk of complications.

If the blood type of the cat in question is unknown, the vet will first take a blood sample for testing. This will allow them to determine the blood type of the cat and administer the correct blood. Doing this will prevent a hemolytic reaction, which can be potentially fatal for already weakened animals. The cat is then given a mild sedative to prevent it from damaging the transfusion equipment. The next step is to shave a small spot over the vein that has been targeted for infusion - this will allow the vet a good view of both the vein and the surrounding area. Next, the vet will insert a needle, followed by an IV catheter into the vein and connect it to an IV bag filled with fresh blood. The drip is then taped in place and the blood bag is elevated to allow the blood to drain naturally via gravity into the cat. Once the transfusion is complete, the vet simply removes the catheter from the cat.

The results of the blood transfusion should be apparent to the owner of the cat immediately after the sedatives have worn off. If it had been suffering from anemia, the animal will appear visibly more energetic and lively than before the transfusion. If blood loss was the problem, the cat's heart rate and breathing should stabilize as the body has more blood to work with. The duration of the effects of the blood transfusion will depend on the precise nature of the condition. In injured cats, they should return to their old selves as their body naturally produces more blood to replace that which was lost. Anemic cats may, dependent on the type of illness affecting them, require longer-term treatment. Cats with autoimmune diseases, meanwhile, might never fully recover.

Cats affected by blood loss should immediately begin to produce new blood, meaning that owners should be primarily concerned with tending to their injuries. In addition to administering antibiotics, open wounds should be monitored, the use of an E-collar may be needed to prevent the animal from pulling out sutures, and painkillers may be prescribed to treat discomfort. Whilst simple lacerations can heal in a few weeks, broken bones and deeper injuries can take months to fully recover from. The treatment plans for cats suffering from low red blood cell count or a low platelet count can vary drastically depending on the exact cause. While many conditions can be resolved in a matter of months with the proper medication, more serious problems such as autoimmune diseases can require lifetime management.

Depending on several factors (including the blood type, age, and overall health of the cat), the price of a blood transfusion can vary quite drastically. Most healthy cats can expect a cost of roughly $500 for the full service of blood type determination, sedation, and transfusion, whilst the price for more infirm animals can be much higher.

While a blood transfusion can be a critically important factor in saving an animal's life, there are some potential drawbacks that owners should be aware of. The first is the risk of the transmission of infections from a donor animal to the recipient. Although rare and avoidable with proper screening, there is a small chance of cross-contamination occurring. Second is the risk of an immune system reaction to new blood, such as a fever or digestive discomfort - though unusual, this can have a large impact on the health of an animal that is already sick.

Whilst autoimmune diseases are by and large hereditary, there are some methods that cat owners can use to prevent a situation in which a blood transfusion may be necessary. One of the main things that owners can do is to feed their animal a rich and healthy diet. Most anemia is caused by iron deficiency and by ensuring their pet is getting good quality, nutritious food, owners can prevent most forms of the condition from setting in. The other big factor is to properly train and socialize the cat other animals live on the property. By preventing rivalries with larger animals (i.e. dogs) from developing, owners can mitigate much of the risk of serious injury from animal attacks.