The prevalence and abundance of helminth parasites in stray dogs from the city of Queretaro in central Mexico.

The prevalence of helminth species in stray dogs, from the capital city of the state of Queretaro, was evaluated. A total of 378 dogs were captured and examined for the presence of helminths from January to December 2008. The results showed that 275 (72.8%) of examined dogs were infected with one or more helminth species. Single infections were observed in 139 (50.5%) of infected dogs and 136 (49.5%) harboured mixed infections. Out of the 378 dogs examined, 208 (55.2%) presented nematodes and 182 (48.1%) cestodes. The prevalences (confidence interval) and mean intensities of infection ( ± SD) of nematodes and cestodes encountered were: Ancylostoma caninum 42.9% (37.9-47.8) and 22.1 ( ± 34.3); Toxocara canis 15.1% (11.8-19.0) and 8.3 ( ± 15.0); Spirocerca lupi 4.5% (2.7-7.1) and 3.9 ( ± 4.8); Toxascaris leonina 2.3% (1.1-4.5) and 4.8 ( ± 3.5); Physaloptera praeputialis 1.9% (0.8-3.8) and 9.7 ( ± 14.9); Dirofilaria immitis 1.3% (0.4-3.1) and 5.6 ( ± 2.1); Oslerus osleri 0.3% (0.0-1.6) and 5 ( ± 0.0); Dipylidium caninum 44.9% (40.0-50.0) and 18.1 ( ± 27.7); Taenia spp. 6.9% (4.7-9.9) and 6.9 ( ± 7.1). There were no significant differences in prevalences observed either between female (68.5%) and male (76.8%) or between young (70.6%) and adult (74.2%) animals. No differences were observed in the ANOVA test for the mean intensity of infection of any of the parasites (P>0.05).