Diagnostics, Assays, and Blood Groups in Veterinary Medicine

Vocabulary-style flashcards covering serology diagnostics, PCR technology, and canine and feline blood group systems and transfusion protocols.

Serology

Testing that utilizes antibodies and enzymes to detect antigens or other antibodies in serum or plasma; also known as immunologic testing.

Sensitivity

A measure of a test’s ability to correctly identify all the positive animals as positive.

Specificity

A measure of a test’s ability to correctly test negative when the patient is truly negative.

Assay

In clinical pathology, a general term that means an analysis of a certain substance (e.g. analyte) in which something about its quantity, quality, or function is determined.

ELISA (enzyme-linked immunosorbent assay)

A serology technique for measuring the presence and amount of an antibody or antigen using an enzyme-attached component that yields a colored product.

PCR (polymerase chain reaction)

A technique where target segments of DNA are searched for in a sample and amplified into thousands or millions of copies to confirm the presence of infectious agents.

Blood group antigens

Structures on the surface of an individual animal’s red blood cells that may react with plasma antibodies of another animal.

Alloantibodies

Naturally occurring (congenital, pre-existing) antibodies that an animal has against another member of its own species with a different red blood cell antigen.

Transfusion

The introduction of whole blood or specific blood components (RBCs, plasma, platelets, or granulocytes) directly into the bloodstream of a recipient.

Fresh whole blood

A transfusion product composed of RBCs, WBCs, platelets, and anticoagulants.

Packed RBCs

A transfusion product consisting of $70-80\%$ RBCs and anticoagulant, typically used for anemia with normal plasma volume.

Fresh frozen plasma

A transfusion product containing plasma, anticoagulants, coagulation factors, and antibodies; used for coagulation factor deficiencies or hypoproteinemia.

Transfusion reaction

Symptoms such as fever, tachycardia, vomiting, or collapse caused by the agglutination or hemolysis of donor red blood cells due to incompatibility.

Crossmatching

A blood test done before transfusion designed to visually confirm compatibility by predicting whether abnormal agglutination of red blood cells will occur.

DEA (Dog Erythrocyte Antigen)

The naming system for canine blood group antigens, followed by a number to designate the specific group (e.g. DEA 1.1).

DEA 1.1

The most concerning and antigenic canine blood group; reactions against this type are the only ones considered clinically significant or life-threatening.

Universal recipient (canine)

Dogs born DEA 1.1 positive; they can receive blood from DEA 1.1 positive or negative donors without being in danger of producing antibodies against it.

Universal donor (canine)

A dog that is DEA 1.1 negative, suitable for initial and subsequent blood transfusions for the same recipient dog.

AB system

The blood group antigen system used in cats, consisting of the groups A, B, and AB.

Type A (feline)

The most common blood type in cats ($90\%$ in the U.S.); these cats possess weak (low titer) alloantibodies against type B.

Type B (feline)

A blood type found in certain pure breeds (e.g. Devon Rex, British Shorthair) that possesses very strong (high titer) alloantibodies against type A.

Type AB (feline)

A rare feline blood type ($< 1\%$) that does not produce alloantibodies against type A or B, making these cats universal recipients.

Major crossmatching

A test used to assess if there are antibodies in the recipient’s plasma (naturally occurring or induced) against the donor’s red blood cells.

Minor crossmatching

A test used to assess if there are antibodies in the donor’s plasma against the recipient’s red blood cells.