PREVALENCE OF INTESTINAL CHLAMYDIAL INFECTION IN PIGS IN THE MIDWEST,AS DETERMINED BY IMMUNOPEROXIDASE STAINING

Objective-To determine prevalence of intestinal chlamydial infection i n pigs and to compare prevalence of diarrhea in infected pigs with tha t in noninfected pigs to evaluate the importance of Chlamydia sp as ca uses of diarrhea in pigs. Animals and Procedures-Intestines from 351 s ick pigs submitted to 2 veterinary diagnostic laboratories and from 96 healthy pigs that were part of an Escherichia coli susceptibility stu dy were examined by immunoperoxidase staining for chlamydial antigen. The proportion of Chlamydia-infected pigs in each group was calculated and compared. The proportion of Chlamydia-infected pigs with diarrhea was compared with the proportion of noninfected pig with diarrhea. Re sults-15% of the sick and healthy pigs were infected with Chlamydia sp . Prevalence of diarrhea was equal between infected and noninfected pi gs. Chlamydia sp were the third most common pathogens identified, and prevalence of chlamydial infection increased after 3 weeks of age. Con clusions and Clinical Relevance-intestinal chlamydiosis is common in c ommercial pigs, but most, if not ail, infections are subclinical. With out collaborative evidence, simply identifying Chlamydia so in feces o r the intestinal tract of pigs with enteritis or diseases of other org an systems should not be considered proof that the organism caused the clinical signs of disease.