Canine mycoplasmas: pathogenicity of mycoplasmas associated with distemper pneumonia.

Mycoplasmas of the following species were isolated from the lungs of dog with distemper: Mycoplasma cynos, Mycoplasma bovigenitalium, Mycoplasma canis, Mycoplasma spumans, and Mycoplasma gateae. One-week-old dogs were inoculated endobronchially with cloned cultures of each species. M. cynos induced a focal pneumonia that were characterized histologically by severe inflammation of bronchi and adjacent respiratory tract tissue. The inflammatory response was initially neutrophilic and later was histiocytic with interstitial lymphoid hyperplasia. M. cynos was recovered from the lungs of inoculated dogs until three weeks after inoculation. A mild inflammatory response was observed in lung tissue of the dog inoculated with M. bovigenitalium, whereas M. canis, M. spumans, and, M. gateae did not induce any visible lesions.