Others such as ''Trichomonas suis'' and ''Trichomonas vaginalis'' reside as commensals, usually in the gastrointestinal tract of other species such as pigs and guinea pigs respectively. ''[[Trichomonas gallinae]]'' occurs in birds. | Others such as ''Trichomonas suis'' and ''Trichomonas vaginalis'' reside as commensals, usually in the gastrointestinal tract of other species such as pigs and guinea pigs respectively. ''[[Trichomonas gallinae]]'' occurs in birds. |