Studies on experimental enteric salmonellosis in ponies.

Clinical, bacteriological, serological and haematological observations were made on 13 adult ponies orally inoculated with Salmonella typhimurium. The results were compared to two control ponies and four others infected by accidental transmission. The clinical responses in inoculated ponies included pyrexia lasting four days and neutropaenia during the first five days after inoculation followed by a neutrophilia. Pyrexia and neutropaenia was associated with maximal shedding of organisms in the rectal faeces. Changes in the character of the faeces occurred between one and two days after inoculation and appeared to be associated with the serological response. Serological responses occurred in all the infected ponies except one. At necropsy, of the 14 ponies with positive cultures in the colon, seven had negative cultures in the rectal faeces. Serological studies performed on 43 clinically normal horses indicated a correlation between age and salmonella agglutination titre.