Equine salmonellosis: a contemporary view.

The practical implications of equine salmonellosis in the light of present knowledge are reviewed. Emphasis is placed on the various clinical forms which the disease may take. These include asymptomatic infections, signs of fever, anorexia and depression, severe acute diarrhoea and the septicaemic form. Diagnosis depends on recovery of the organism from the blood or faeces or, at necropsy, from tissues. In asymptomatic infections, it may be necessary to make serial faecal cultures over several days before a negative diagnosis may be made with any degree of certainty. Isolation of salmonellae is more readily accomplished when clinical signs, particularly diarrhoea, are present. Treatment depends on the nature of the infection and ranges from no measures in some asymptomatic cases to those in which antimicrobial drugs, fluids, electrolytes and buffers are administered. In both asymptomatic and symptomatic cases, faecal shedding continues during and after antimicrobial therapy. The part played by stress (eg, heat, chilling and over-crowding) is discussed in relation to pathogenesis. Measures of control depend on reducing exposure to the organism and a number of steps to achieve this are described.