The Importance of a Blood Bank to Companion Animal Health
Blood transfusions can be critical, life-saving procedures. Blood loss through trauma or toxins (e.g., anticoagulant rodenticide poison) or destruction of a patient’s red blood cells due to immune-mediated hemolytic anemia (IMHA) or ingestion of zinc (e.g., pennies) can quickly lead to severe anemia and possibly death, an outcome that can be averted through the administration of blood transfusions.
PABB manages a large volunteer blood donor program to meet the transfusion needs of the patients at Penn Vet. PABB carefully screens both canine and feline blood donors for general health and infectious diseases to protect both the blood donor and the recipient.
All blood is collected by certified veterinary technicians and processed and stored in-house to maintain PABB’s high standards for quality blood products. A unit of blood is typically separated into packed red blood cells (PRBCs) and plasma, though other blood components (e.g., platelet concentrate, cryoprecipitate) are prepared to meet the specific transfusion needs of a patient. Administration of blood components rather than whole blood allows a single blood donation to help more than one patient and may decrease the risk of certain types of transfusion reactions.
PABB collaborates with many services in Ryan Hospital, including ES, ICU, surgery, and internal medicine.
How the Penn Vet Blood Donor Program Works
Dog owners volunteer to participate in the program. To be eligible as a blood donor, the dog must be 1-6 years old, weigh at least 55 lbs., have a good temperament and overall excellent health, and not on any medications (other than heartworm preventative and flea/tick control).
The PABB bloodmobile drives to locations such as veterinary hospitals and breed clubs on prearranged dates to collect blood.
- A veterinary nurse reviews the dog’s medical history and performs a brief exam. The nurse then determines the dog’s blood type and hemoglobin level (to make sure the donor is not anemic prior to blood donation). Dogs must be DEA1.1 negative (see below),
- Dogs who donate blood are not sedated, so willing compliance is an important criterion to qualify as a canine blood donor.
- Once the blood (a pint) is collected, the unit is processed and stored until results of the blood tests submitted for general health and infectious disease screening are available; if all clear, the units are released for transfusion.
- If a dog participates in the blood donor program, their owner will receive a free bag or case of food for each blood donation. A dog can donate between 4-5 times per year, although no more than once every six weeks.
What is Canine DEA 1.1?
- The internationally accepted nomenclature for the canine blood group system is Dog Erythrocyte Antigen (DEA). The DEA 1.1 antigen is the most clinically significant blood type in dogs and the only canine antigen for which there is a commercially available blood typing kit. The DEA 1.1 blood group is highly antigenic, which means that administration of DEA 1.1-positive RBCs to a dog that is DEA 1.1-negative will result in formation of antibodies to the DEA 1.1 antigen. The clinical consequences of the formation of these alloantibodies include a delayed hemolytic transfusion reaction (i.e., the newly formed antibodies will result in destruction of any of the previously transfused DEA 1.1-positive RBCs still in the patient’s circulation) or a potentially life-threatening acute hemolytic transfusion reaction if the patient were to receive DEA 1.1-positive RBCs again.
- It is estimated that 40% of dogs are DEA 1.1-positive. A DEA 1.1-positive dog can receive either DEA 1.1- positive or DEA 1.1-negative blood. However, a dog that is DEA 1.1-negative should receive only DEA 1.1-negative blood.
PABB maintains cats that serve as blood donors for three years and are then adopted into forever homes. In addition, cats owned by Penn Vet staff and students are recruited to serve as blood donors.
An ideal feline blood donor is friendly and in good body condition, weighing at least 10 lbs. The cat must be in overall excellent health and live exclusively indoors. Donors must test negative for feline leukemia virus and feline immunodeficiency virus, as well as blood-borne pathogens such as Mycoplasma hemofelis.
How Blood is Collected
- For cats, sedation is often necessary to keep a cat sufficiently still to make a safe donation. A successful blood donation is 40 ml.
Cat Blood Types and Cross-matching
The feline blood group system consists of three blood types: type A, type B, or type AB.
Type A is the most common blood type (approximately 95% or more of domestic shorthair cats are type A), but certain breeds of cats, such as the Dexon Rex and British shorthair, have a high frequency (~40%) of type B blood.
Unlike dogs, and similar to humans, cats have naturally occurring antibodies against the other blood type (except for the rare type AB cats that do not have alloantibodies). Cats with type B blood have very strong anti-A antibodies, which means that they can have a serious and potentially fatal reaction if inadvertently administered type A blood.
Feline patients should receive only type-compatible blood. The rare AB cat may receive type A blood if a type AB donor is unavailable. Also, since cats have RBCs antigens (e.g., Mik) other than the AB blood group system, ideally a blood cross-match should be performed before all RBC transfusions to ensure serologic compatibility.