The Dynamic Nature of Canine and Feline Infectious Disease Risks in the Twenty-first Century.

Canine and feline infectious diseases are constantly changing in frequency and location. Numerous drivers or determinants of these changes are suspected, including emergence of new pathogens; change in virulence and resistance of existing pathogens; change in land use, climate, and weather; travel and trade; habitat destruction and urbanization; change in animal-animal contact networks; host susceptibility; availability and uptake of prevention measures; and change in ability to detect pathogens and track diseases. This article explores each of these proposed drivers and examines examples of feline and canine diseases likely to be influenced by them.