Abstract
This research was conducted to determine the prevalence and pathological lesion of Trichomonas gallinae in pigeons in the northeast part of Iran. Wet mount preparations from the oral cavity/crop of 418 pigeons (Columba livia) captured from various locations in Khorasan province analyzed for T. gallinae by Giemsa's staining between April 2008 and June 2009. A total of 418 pigeons, 37.32% (n = 156) were infected with T. gallinae. Macroscopically, the oropharynx of infected pigeons has white, caseous lesions or stomatitis. Microscopically, there was moderate congestion with infiltration of mononuclear inflammatory cells in the lamina propria of pharynx, hyperplasia of mucous cells in epithelia of trachea with infiltration of mononuclear inflammatory cells, numerous granulomatous foci in the livers with many multinucleated giant cells, tubulointerstitial nephritis with multifocal to diffuse infiltration of mostly mononuclear inflammatory cells in the kidneys. In the present paper we have described for the first time the co-existence of both genotypes of T. gallinae based on pathological lesions in this area.