The development of complement-fixing antibody in horses after infection with Mycoplasma equirhinis

Abstract

Of 6 ponies apparently free of mycoplasmas, without antibody to M. equirhinis and with only very low values against N3, 2 were experimentally infected with M. equirhinis, 2 with the equine mycoplasma strain N3 and 2 remained uninoculated. The inocula were introduced via the nose and reisolation was by means of oropharyngeal and nasopharyngeal swabs. N3 was not recovered from any pony but M. equirhinis was recovered in large numbers within a few days from all 6 animals indicating that the organism spread naturally from the artificially infected ponies to the others. After about 6 weeks it became increasingly difficult to isolate the organisms and levels of complement-fixing antibody rose first in the nasal secretions and later in the serum. These fell after several weeks to undetectable levels. No clinical signs of infection were seen.