BACTERIAL INTESTINAL INFECTIONS OF SWINE

Bacterial intestinal infections are one of the main diseases in pigs of different ages. Bacterial diseases of the pig digestive tract lead to significant economic losses due to high mortality, reduced growth, treatment and prevention costs. 
The main bacterial intestinal infections of pigs are anaerobic enterotoxemia (clostridiosis), colibacillosis, intestinal salmonellosis, dysentery, proliferative enteropathy (ileitis). 
Anaerobic enterotoxemia of pigs is an acute toxic-infectious disease mainly of newborn piglets, caused by pathogenic bacteria of the genus Clostridium and characterized by hemorrhagic-necrotic inflammation of the intestinal mucosa, diarrhea and toxicosis. 
Swine colibacillosis is an intestinal infection caused by the enterotoxigenic Escherichia coli, which is able to produce enterotoxins that locally affect the intestines of pigs, causing diarrheal syndrome. 
Intestinal salmonellosis is a factorial infection. The causative agents are enteropathogenic salmonella (mainly Salmonella enterica serotype typhimurium), which cause inflammation and necrosis of the small and large intestine, leading to diarrhea, which may be accompanied by generalized sepsis. 
Dysentery is a severe enteroinfection of pigs caused by the anaerobic bacterium Brachyspira hyodysenteriae, characterized by fever, debilitating mucohemorrhagic diarrhea and dehydration, leading to high mortality among animals. 
Proliferative enteropathy is a sporadic disease of pigs caused by Lawsonia intracellularis. The acute form of ileitis, known as proliferative hemorrhagic enteritis, is characterized by intestinal hemorrhage and sudden death, and usually occurs in pigs older than 4 months. 
Diarrhea in piglets can also be caused by enterococci (Enterococcus spp.) and chlamydia (Chlamydia suis). Enterococcal bacteria cause diarrhea in newborn piglets, and intestinal chlamydia infections are mostly common in rearing piglets, and it is believed that most intestinal infections caused by chlamydia are subclinical. 
The literature review regarding the etiology, pathogenesis and clinical diagnosis of major bacterial intestinal infections in pigs is presented in the article.