Susceptibility of small laboratory animals to pygidiopsis genata [trematoda: heterophyidae]

Three species of animals: golden hamsters, white mice and albino rats were evaluated for susceptibility to P. genata. The optimal dose of metacercariae for infection was determined in mice and found to be 300 per animal. Thirty four animals of each species were then orally infected with 300 metacercariae each. The metacercariae were obtained from Tilapia caught from Idku and Maryut lakes. Two animals of each species were sacrificed daily for the first ten days, then weekly for the first month and monthly until the fifth month following infection. Worms were recovered for counting and measurements. Recovery rates [live worms/300 metacercariae] one week after infection were 35.2% in mice, 20% in hamsters, and 12.4% in rats. Spontaneous recovery took place after 5 months in mice, 4 months in hamsters, and 2 months in rats. The worms were found in the small intestine with most of them being in the upper third and a few in the middle third. The flukes were generally larger in size in the hamster than in mice and rats. Results indicate that the hamster is more suitable for P. genata infection than the mouse or the rat