trichinella spiralis is one of the causative agents of the trichinellosis, is a zoonosis of world-wide distribution, affects to big number of mammals like this as to the human. in mexico the main cause of infection associate with the consumption of pig infected meat with t. spiralis. in this work detected the phenotypical changes in long evans rats products infected with trichinells spiralis and threated with albendazol medication. use rats cepa long evans ina reproductive age. divided in groups, included controls and with treatment varying of one to fourteen days of treatment, to synchronize the management in the rats realized vaginal.smears for the detection of the parasites used direct techniques of understanding in plate and artificial digestion and the indirect technician of miid, for the phenotypical changes of baby rats obtained realized a detailed analysis with stereoscopic microscope.