Chlamydial pelvic infection in cats: a model for the study of human pelvic inflammatory disease.

The inoculation of feline keratoconjunctivitis agent (Chlamydia psittaci) directly into the oviducts of eight cats produced an acute disease that was characterised by hyperaemia of the tissue and pronounced polymorphonuclear leucocyte infiltration of the epithelium and subepithelial stroma. The lumens of the tubes contained exudates of desquamated epithelial cells and polymorphonuclear leucocytes. After about 30 days the disease subsided leaving chronic inflammation with the tissue infiltrated with both polymorphonuclear and mononuclear cells. Fimbrial scarring and formation of adhesions were apparent by 40 to 50 days after inoculation. Chlamydiae were isolated in McCoy cell cultures from most cats, in one for as long as 51 days after inoculation. Inclusions were seen in histological sections or smears of cells from the fimbriae of four of the eight cats. Six of the eight cats developed antibodies to feline keratoconjunctivitis agent, which were detectable as early as 12 days after inoculation. To facilitate repeated examinations of the cats' fallopian tubes, techniques for laparoscopy in cats and for the collection of specimens while under laparoscopic examination were developed. The latter technique has since been applied successfully in man.