[A serological study of the contagious equine metritis: comparison between indirect immunofluorescence, slow...

Serological response of pony mares to contagious equine metritis is studied comparing three techniques: slow agglutination, complement fixation and indirect immunofluorescence. Sera were taken from pony mares vaccinated with a heat inactivated suspension of Haemophilus equigenitalis, from experimentally-infected pony mares and from healthy horses. All three reactions detected antibodies in vaccinated and infected animals. The highest titers are observed with vaccinated mares. Titers are low in infected animals. Antibodies detected by indirect immunofluorescence appeared sooner and persisted longer in diseased animals than agglutinating or complement fixing antibodies. Only indirect immunofluorescence revealed a new contamination of two mares following coitus with a stallion excreting H. equigenitalis. Indirect immunofluorescence must be recommended in diagnosis of contagious equine metritis and in detection of chronic carriers.