Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: December 1, 2000
Publication Date: N/A
Technical Abstract: Chlamydiosis in livestock is caused by a number of species or strains of organisms in the Family Chlamydiaceae, which recently has been divided into two genera, Chlamydia and Chlamydophila, and 9 species. The disease chlamydiosis is characterized by the development of a variety of clinical symptoms. The clinical syndrome depends on the species and strain of Chlamydia or Chlamydophila, the host species, and on the affected organ system. Chlamydial diseases can affect most livestock species, including horses, cows, pigs, sheep and goats. The identified chlamydial strains are fairly host specific, each primarily infecting a given specie or type of animal and each causing specific clinical diseases. Chlamydial diseases are known to affect the gastrointestinal, respiratory, reproductive, and nervous systems, and joints and eyes. Disease severity can vary from life threatening to asymptomatic, but the ususal syndrome is a moderate to mild clinical disease leading to a persistent infection. Recurrence of the disease and/or shedding of the organism can occur following stress or physiological changes such as estrus. What is not known at the present time is what synergistic effect these persistent chlamydial infections may have during concurrent infections with other pathogens.