Veterinary Epidemiology and Zoonosis

INTRINSIC AND EXINTRISIC DETERMINANTS

• Some determinants both primary and secondary are internal to the host.
  • Examples: Genetic constitution, including aberrant genes (which are primary causes of genetic disorders), species, breed and sex.
• These determinants are intrinsic, also termed endogenous.
• In contrast some determinants are external to the host; for instance, transportation, which may result in physical trauma, producing bruising of carcasses. Such determinants are extrinsic, also termed as exogenous. 

Intrinsic and extrinsic determinants
Intrinsic				Extrinsic
Species Breed Physical type	Hereditary Defects Resistance	Sex	Age	Physiological state	Animal use	Level of husbandry