atrophy: decrease in size of a normally developed tissue or organ

blood serum test: analysis of the serum to identify specific components

capsid: the protein shell that surrounds a virus particle

colitis: inflammation of the colon

colostrum: the first milk secreted at the time of parturition which is rich in antibodies that confer passive immunity to the newborn

cuboidal: an epithelial cell that is shaped like a cube

disaccharidases: a sugar molecule with two simple sugar units

dysentery: an infectious disease marked by inflammation and ulceration of the lower part of the bowels, with diarrhea containing blood and mucous

dystocia: difficulty calving

enteritis: inflammation of the intestinal mucosa

enterocytes: the main cells in the small intestinal lining

enteropathogenic: a pathogen that attacks the intestinal tract

etiology: the cause or origin of a disease

hypervolemia: abnormal increase in the volume of circulating fluid in the body

hypoglycemia: low blood sugar levels

immunoglobulins: antibodies produced in the host that bind to and neutralize pathogens

incubation period: the interval between infection and clinical signs of disease

lactic acidosis: metabolic acidosis due to anaerobic metabolism and accumulation of lactic acid

morbidity: the relative frequency of disease in a population

mortality: the relative frequency of deaths in a population

naïve immune system: immune system that has not been exposed to environmental pathogens and thus has fewer antibodies to combat disease

passive transfer: transfer of antibodies from the dam to the calf through ingestion of colostrum and absorption through the calf’s intestine

Peyer’s patches: regions of lymphoid tissue in the small intestinal mucosa

pneumoenteric: pertaining to lungs and intestine

positive sense RNA: RNA that can be immediately translated by the cell (the same as viral RNA)

seropositive: an animal with detectable serum antibodies to a certain pathogen

serum: the component of blood that remains after cells and clotting factors have been removed

squamous: a flat, scale-like epithelial cell

villous: small finger like projections of the intestinal lining

All above definitions obtained from:

Blood, D. C. and V. P. Studdert. Saunder’s Comprehensive Vet Dictionary.