Changes in the prevalence of parasitic nematode infections in dogs from animal asylums in Warsaw and surroundings

The distribution of parasitic nematodes of dogs from three shelters for homeless animals in the Warsaw region (Celestynów and Milanówek near Warsaw, Paluch in Warsaw) was investigated. It was found that since our previous investigations (1993-1995) the prevalence of nematode infections had increased in Celestynów and Milanówek and decreased in the municipal shelter in Warsaw (Paluch). The highest percentage of infected animals was found in Celestynów (as in 1993-1995). What can be the importance of local environmental conditions for the prevalence of nematode infections.