Canine Blood Transfusion

"Canine blood transfusion is usually required in cases of acute hemolysis (break down of red blood cells) or hemorrhage (bleeding). It may also be required to treat acute or chronic anemia (below normal levels of red blood cells), or some dogs may require repeated transfusions of whole blood, plasma or platelets in order to treat hemostatic disorders (problem with the flow of blood). The diversity of blood groups, lack of availability of blood typing, hindrances in the selection of the donor, makes dog blood transfusion a relatively difficult job  Extra care is required prior to related procedures. Collection, storage and transfusion are three tiers for canine blood transfusion, each of which should be performed aseptically (free of pathogenic microorganisms) and according to recommendations. Otherwise, dogs may suffer several risks related to the transfusion."

Indications of Canine Blood Transfusion:

Canine blood transfusion is usually indicated in acute cases of blood cell breakdown or when there is a severe loss of blood. Similarly, dogs with acute or chronic anemia (below normal level of red blood cells), due to any cause can require a blood transfusion. Some dogs may not require whole blood, but a part of the blood, such as plasma or platelets.

Whole blood transfusion is usually not indicated; preferably a part of the blood that is required for the purpose identified should be transfused. For example, if the treatment objective is to only improve the oxygen-carrying capability of blood only, red blood cells should only be transfused instead of whole blood. Platelets are usually not required in blood transfusions for hemorrhage; as the number of platelets naturally increases. Similarly, only crystalloid colloid solutions, combined with packed red blood cells are required in some transfusions.

Defining the treatment required and then limiting the transfusion to the indicated part of the blood, not only helps to reduce associated risks, but also helps to define the requirements of the canine blood transfusion.

Canine blood transfusions can be distributed into three different parts, collection, storage and transfusion. Each step requires that protocols be followed before heading towards the next step.

Minimizing the Risks of Canine Blood Collection

Blood for transfusion must be collected from healthy, disease free and vaccinated donors. The diversity of blood groups in dogs, makes it hard to select appropriate donors, thus blood grouping, typing or cross matching; should be preferably done to reduce the chance of complications, such as acute hemolysis (the destruction of dissolution of red blood cells, with the subsequent release of hemoglobin) and incompatibility; which can turn into a severe medical emergency.

Canine Blood Storage

Collected blood must be stored in an aseptic (sterile) environment. Citrate phosphate dextrose adenine (CPDA-1) is the choice anti-coagulant for prolonged storage. Vacuum bags containing the appropriate amounts of coagulant; should be preferred over vacuum bottles; as the degree of damage is lower in bags. Heparin is another common anti-coagulant; which is not recommended for dogs, as it activates platelets due to its longer half-life in recipients.

Collected blood, mixed with CDPA–1, can be stored at 4 Degrees Celsius, for 3 weeks. Plasma can be removed from the blood for prolonged storage. Plasma should be frozen at 20 to 30 Degrees Celsius (68 degrees to 86 degrees Fahrenheit) within 6 hours of separation, will ensure quality. The blood is usable for 1 year.

Canine Blood Transfusion

Blood can be transfused, as a whole or parts as required by the condition being treated. Examples are anemia and hemostatic (red blood cell) disorders. These products are stored in different forms and in different environments and should only be administered as directed.

Canine Whole Blood Transfusion

Whole blood transfusion is indicated in hemorrhage, or hypovolemia (blood circulation deficiency). Dogs with more than a 30% loss of blood should only be transfused with whole blood. Whole blood in most conditions cannot be administered due to anti-coagulant dependency and storage restrictions i.e. whole blood can only be stored for 4 weeks.

Canine Plasma Transfusion

Plasma is usually required in cases of deficiency in multiple clotting factors, and hypoproteinemia (abnormally low levels of protein in the blood); as stored plasma contains all clotting factors except platelets.

Plasma can be stored for 0.5–1 year at 70 Degrees Celsius (158 degrees Fahrenheit). In case blood is not available, plasma can also be used to control hypovolemia (diminished volume of circulating blood.

Packed Red Cells Transfusion

Packed cells are used mostly for the treatment of anemia. These are re-suspended in 0.9% NaCl solution prior to administration; which reduces their viscosity. Packed red cells can be refrigerated and used for only 3 weeks, after collection and separation.

Risks of Canine Blood Transfusion

Acute hemolysis (break down of red blood cells) is the most common risk associated with a canine blood transfusion. It is less frequent in dogs, but is suspected in cases where repeated blood transfusions are required. This may occur because of a significant number of anti-bodies preformed in the recipient, which is more common in repeatedly transfused dogs.

Other risks, such as contamination, sepsis, hypocalcemia and hypervolemia are associated with canine blood transfusion, but all of them occur due to carelessness.

Some dogs may show signs of vomiting, fever or illness after transfusion; which should be monitored closely, as these may occur due to miscreants (elements that shouldn't be in the blood) in transfused blood; such as bacteria or contamination.

References:

The Merck/Merical Veterinary Manual

C. Bowden, et. all. “Text Book of Veterinary Medical Nursing” (Elsevier Health Sciences. 2003)

Washington State University College of Veterinary Medicine