Cerebellar hypoplasia - deficiency of cells of the cerebellum, the degree and distribution of which is variable.  (1)

Core vaccine - a vaccine that should be included in an animal's vaccination program to prevent disease from a high risk virus.

ELISA (enzyme-linked immunosorbant assay) - a type of test used to detect and measure either antigen of a virus or antibody produced to a virus.  The antigen or antibody is bound to a solid substance (polystyrene surface), and a second antibody to which enzyme is conjugated is added, followed by a substrate for the enzyme.  Positive results are indicated by a colour change.  (1)

Histology - section of anatomy dealing with microscopic structure, composition and function of tissues.  (1)

Immunofluorescence - a method of determining the location of antigen (or antibody) in a tissue section or smear using a specific antibody (or antigen) labeled with a fluorochrome.  (1)

Lameness - incapable of normal locomotion; deviation from the normal gait.  (1)

Macrophages - large, mononuclear, highly phagocytic cells derived from bone marrow that participate in the 'cleaning-up' of cellular debris and infections within a tissue.  (1)

Non-core vaccine - a vaccine that is not normally included in an animal's vaccination program, unless there is high risk for infection.

PCR (polymerase chain reaction) - a method by which a specific sequence of DNA is amplified exponentially to a concentration that is detectable by various lab techniques.  (1)

Vaccine - a suspension of attenuated or killed microorganisms (viruses, bacteria or rickettsiae), administered for prevention, amelioration or treatment of infectious diseases.  (1)

- Attenuated (modified-live) vaccine - a vaccine prepared from live microorganisms that have lost their virulence but retain their ability to induce protective immmunity.  (1)

- Inactivated vaccine - a vaccine prepared from dead microorganisms.  (1)

Virulence - the degree of pathogenicity of a microorganism as indicated by case fatality rates and/or its ability to invade the tissues of the host.  (1)