[Mycoplasma bovis infection: epidemiological and clinical survey of dairy cattle farms in Morocco].

An epidemiological survey of M bovis infection in dairy cattle was performed in 10 herds of the Gharb's region, by sampling the animals three times with a two-month interval, between November 1985 and May 1986. M bovis was isolated in six herds with calf enzootic bronchopneumonia with a total frequency of 39% during the first visit, then 25 and 13% after two and four months, respectively. The severity of the symptoms seems closely related to the age of the animals: the youngest being the most susceptible. On the other hand, M bovis was isolated in two herds from 11% of cows suffering from clinical and subclinical mastitis. The isolation occurs at any lactation stage and the infection lasted more than four months in 40% of the animals. These results suggest that mycoplasma are important bovine pathogens in Morocco.