External and internal influences on disease risk in cats

Obesity isalso a common problem of cats; the prevalence rangesfrom 1.8 to 40% and appears to be increasing.Hyperthyroidism, first reported in 1979, also appearsto be diagnosed with increasing frequency. The causesof these problems have not yet been clearly elucidatedand may be influenced by both internal and externalfactors. Internal factors include the cat’s genetic andexperiential background as well as its temperament.External factors include such variables as the complex-ity of the environment, resource quality and availabili-ty, and presence of sources of threat and conflict. Ofcourse, these factors are not mutually exclusive andvary over a continuum that includes elements of each.