A recently recognised venereal disease of horses and its causative organism

Abstract

Summary In the spring of 1977 an unusual outbreak of venereally transmitted acute metritis accompanied by a marked reduction in the rate of conception was reported among thoroughbred mares on stud farms in and around Newmarket, Suffolk. The condition has been reproduced experimentally in healthy pony mares by inoculating into the uterine cervix a previously undescribed Gram-negative coccobacillus first isolated in the Regional Public Health Laboratory, Cambridge, from thoroughbred mares with the disease. A formal proposal made to the International Committee for Systematic Bacteriology that the organism should be placed in the genus Haemophilus and given the name Haemophilus equigenitalis has not been accepted. Efforts to infect other species of animals with the organism have not been successful but agglutinins have been found in human serum in the Regional Public Health Laboratory, Cambridge, the highest incidence (37 per cent) being in serum from men with non-gonococcal urethritis. Agglutinins were not found, however, in the serum of four veterinary surgeons who had had exceptionally close contact with infected horses. The possible significance of these findings is discussed.