Isolation of mycoplasma spp. from racing pigeons (Columba livia).

Live and dead racing pigeons (Columba livia) from five lofts in Norfolk and Suffolk were examined clinically and cultured for Mycoplasma spp. Both clinically healthy birds and those showing signs of mild respiratory disease were included. The oropharynx was the culture site for 130 live birds, the nasal sinuses and other tissues for 58 carcases. Mycoplasma columbinum, M. columborale and M. columbinasale were isolated from the oropharynges and nasal sinuses; M. columbinum and M. columbinasale from the brain and M. columbinum and M. columborale from lungs and air sacs. One or more of these three Mycoplasma spp. was isolated at necropsy from 28% of 58 pigeons. Only 11% of 37 pigeons reacted sero-logically by the metabolism inhibition test to M. columbinum and none to M. columborale. Twenty-five birds examined for M. gallisepticum antibody by the haemagglutination-inhibition test were negative. No sex or age predilection to infection with Mycoplasma was apparent. About 10% of pigeons in all five lofts showed clinical signs of the respiratory disease sometimes described as 'mycoplasmosis catarrh', but most dead birds from which Mycoplasma spp. were isolated also had concomitant infections of various kinds. Although suggestive, the results of these investigations provide no clear evidence that Mycoplasma spp. are aetiologically involved in natural respiratory disease of pigeons. No conclusive satisfactory treatment was found for the elimination of mycoplasmas.