Abstract
Neisseria sp. is a Gram-negative diplococcus bacterium usually present on the mucosal surfaces of animals without causing an obvious pathology. The objective of this study was to report the isolation of Neisseria sp. from severe cases of pyogranulomatous pneumonia with the formation of a Splendore-Hoeppli structure in two cats treated at a veterinary hospital. This paper suggests that the Neisseria genus members may be involved in lower respiratory tract infections in cats, with the molecular diagnosis being a necessary method for the correct identification of this bacteria in animals.