It was conducted a chamber analysis of scientific trends in solving the problems of chlamydia in pigs and focusing on the most effective methods of the disease prevention and the treatment of animals. It has been determined that chlamydia are positioned as bacteria and viruses, and therefore are quite common among farm animals, and poultry: about 90 million new cases of chlamydia disease in animals, in particular pigs, are registered in the world. Some types of chlamydia threaten the health of people and animals, reducing the productivity of the latter. Chlamydiae are Gram-negative, obligate intracellular bacteria with a complex developmental cycle consisting of two stages, such as the elementary body (infectious) and the reticulum body. This determines their latency and resistance to antibiotics and other therapeutic drugs. It has been determined that chlamydia are similar to viruses and have the ability to cause dangerous formations in the body of animals. Chlamydial disease in pigs manifests as conjunctivitis, pneumonia, and pseudomembranous or necrotizing enteritis, which is confirmed by the experimental reproduction of the infection in gnotobiotic pigs using clinical isolates. In addition, chlamydia is associated with pericarditis, polyarthritis and polyserositis in piglets and numerous reproductive problems such as vaginal discharge from the sow, disruption of the sexual cycle, abortions, mummification of fetuses, the birth of weak piglets, the increased perinatal and neonatal mortality, as well as orchitis, epididymitis and urethritis in boars. However, for most of these diseases, the ultimate role of chlamydia is not fully defined. Chlamydia is considered a pathogen in pigs, chlamydia tests are not performed in most available veterinary diagnostic laboratories. Chlamydia often occurs together with other pathogens, and this phenomenon complicates the recovery of pigs to a certain extent. Infection of animals with chlamydia occurs as a result of direct contact of their mucous membranes with the causative agent of the disease. The systematic control of the presence of chlamydia in animals of the breeding herd will prevent a decrease in their productivity, that is, the substantial economic losses. The study of chlamydia by the molecular genetic method (PCR) will allow to identify sick animals and carry out their illumination, which is the most promising and will ensure the detection of sick animals. Key words: chlamydia, infection, bacteria, animal, pig, pathogenesis, symptoms, diagnostic methods.