By Dr. Jennifer Bronk
It’s important to understand the impact of anemia and blood transfusions in dogs. Anemia, or low red blood cells (RBCs) is the primary indicator for blood transfusions in dogs. Anemia can be caused by acute or chronic blood loss, hemolysis (destruction of RBCs) or decreased production of RBC’s. Packed RBCs and fresh whole blood are the two main blood products used for the treatment of anemia. The choice between the two is made based on patient status as well as their requirements. Fresh whole blood includes platelets, proteins and clotting factors among other things, and comes with a higher volume to be infused, which every patient may not tolerate.
Dogs in Need of Blood Transfusions
What kinds of patients may need a blood transfusion? Some of them will be very sick and some won’t.
Some of the more common examples are: hemoabdomen (bleeding within the abdominal cavity); Immune-mediated Hemolytic Anemia (IMHA) where the body destroys it’s own RBCs; and thrombocytopenia (very low platelets causing abnormal bleeding and subsequent anemia).
Most often these patients are dogs, so this article focuses on them, but cats can receive transfusions too.
Careful consideration is given to potential candidates of blood transfusions. Some of the main factors to consider are: patient status, availability of resources (blood products and staffing), and cost of the procedure.
Dogs Have Blood Types Too
Dogs do have blood types, and they are classified based on the the dog erythrocyte antigen (DEA) system. DEA 1.1 is the most antigenic (reactive) blood type, and is the only type that is routinely tested for. DEA 1.1 NEGATIVE blood is considered to be “universal donor blood”, and can be given safely to any dog who has never had a transfusion before.
There are many other DEA types but those details are beyond the scope of this article. Cats, on the other hand, should always be blood typed. Most are type A, but if a type B cat receives type A blood, serious and often fatal consequences are likely.
Cross matching is a complex process of testing both the donor blood and the recipient’s blood to make sure they are compatible (ie no reaction in a laboratory setting before the blood is actually given). A dog can receive its first transfusion without a cross-match performed if it is given universal donor blood, however some clinicians still prefer to cross match to be on the safe side. If a dog is likely to receive subsequent transfusions, or has received prior transfusions, they should receive their type blood and also be crossmatched to a compatible donor.
Dog Transfusion Procedure Explained
Once the patient is crossmatched and the blood product is deemed compatible, the actual transfusion can be given. This is only performed in a hospital setting with appropriate monitoring. A dedicated intravenous (IV) catheter is required, and no other fluids or medications are to be given in that catheter with the blood product.
Ideally, all other treatments as well as food are withheld during administration in order to minimize potential reactions. The veterinarian must determine the volume of blood that is to be transfused, a calculation that is based on body weight, but also on how anemic and/or stable the patient is.
The transfusion itself takes about 4 hours to complete. The rate at which it is given is started very slowly and gradually increased as the patient tolerates. In a life threatening emergency situation where the pet may need blood immediately, it can be given as fast as possible, but this is not ideal.
Dog Blood Transfusion Complications
The patient’s body temperature, heart rate, respiratory rate and blood pressure are monitored every 10 minutes for the first 30 minutes and then every 30 minutes thereafter until the transfusion is complete. If any of the vital parameters change significantly the transfusion may be slowed or even stopped depending on the severity of the reaction.
Other mild reactions can include fever, facial swelling, and vomiting, and can often be treated with diphenhydramine (Benadryl) or steroids. Patients should continue to be monitored for about an hour after the transfusion is complete. Because the transfusion increases the blood volume of the patient, their fluid status will need to be reassessed, especially in those patients with unstable cardiovascular status.
The patient’s packed cell volumed (PCV) is checked 1-6 hours after the transfusion. The PCV is a measurement of the degree of anemia, and is monitored closely in anemic patients. If there is ongoing loss of RBCs a subsequent transfusion may be necessary.
Dog Blood Transfusion Costs
Transfusion costs can range depending on clinic type and location, but a range of $400-600 is average. Most of the time a pet doesn’t come in just for the transfusion, but is hospitalized for ongoing care, and the transfusion is only a fraction of the necessary treatments.
Because they are expensive and somewhat difficult to maintain, blood products are not a staple item in many clinics. Most ER’s and specialty hospitals do stock limited quantities of blood, but the average general practitioner does not. There are hospitals that have blood banks, and they often sell the blood products to other clinics in the area.
Some veterinary hospitals have blood donor animals, or pets who are kept by the clinic and their staff, and are available to donate blood when needed. Often, once it is determined that a patient needs a blood transfusion, the clinic must either obtain the blood from another hospital, or transfer the patient to a place where the transfusion can be readily provided.
While they do come with intrinsic risks and inherent costs, transfusions can be life saving in many situations. Whether the pet is sick or injured, blood products often hold the key to a successful outcome for the patient.
About the Author
Dr. Jennifer Bronk attended the University of Maryland at College Park for her undergraduate training in Kinesiology. She then moved to California where for the next six years she took pre-veterinary classes and worked in various veterinary clinics. She earned her Doctorate of Veterinary Medicine degree from the University of California at Davis in 2007.
After graduating from veterinary school, Dr. Bronk moved to Washington State to complete a year-long equine medicine and surgery internship. She practiced as a large-animal veterinarian for two years, then went back to her first love of small-animal emergency and critical care medicine where she has been ever since.
Dr. Bronk and her husband live in the beautiful Pacific Northwest with their daughter and twin sons. When she has a moment between her busy work and family schedules, Dr. Bronk enjoys staying active by running, trail racing, hiking and snowboarding.