A retrospective study was conducted over the results of cytological examination in the files of the Department of Cytopathology, Laboratory of Animal Pathology, School of Veterinary Medicine and Animal Science, São Paulo State University, Botucatu, SP, Brazil, from January 1994 to December 2008. Out of 139,986 animals referred to the teaching Veterinary Hospital, 11,468 (8.2%) were submitted to cytological examination. From these animals, 57.28% had a neoplastic lesion, 19.28% had inflammatory lesions, and 14.79% had non-neoplastic processes (immune-mediated, degenerative, hyperplastic, or dysplastic condition). By means of cytology, 7.28% of the cases were unable to be diagnosed, and there was no recorded diagnostic information in 1.37% of cases. The species that more commonly had samples submitted to cytology was the dog (92.06%), followed by cats (4.08%), cattle (1.77%), and horses (1.30%). As to the predominance of the observed processes, greater importance was given to neoplastic lesions. These were prevalent in dogs (59.18%), with a mean age of 119.60 months, and affecting mainly females (61.61%). The annual increase observed over the 15 years of application of cytology demonstrates that the cytological examination is a method of great importance to confirm, suggest, or exclude the diagnosis of various diseases, including cancer, in all animal species.
Cytology; epidemiology; prevalence; animals