A vaccine composition suitable for vaccinating dogs comprising an agent capable of raising an immune response against Mycoplasma cynos (M. cynos) in a dog, wherein said agent comprises inactivated or attenuated M. cynos.Use of an agent capable of raising an immune response against M. cynos in a dog, wherein said agent comprises inactivated or attenuated M. cynos, or an immunogenic fragment of M. cynos, or a nucleic acid encoding said fragment, in the preparation of a medicament for prophylaxis or treatment of canine infectious respiratory disease (CIRD).