Sarcocystis spp

Lesniak, Ines, Franz, Mathias, Heckmann, Ilja, Greenwood, Alex D., Hofer, Heribert & Krone, Oliver, 2017, Surrogate hosts: Hunting dogs and recolonizing grey wolves share their endoparasites, International Journal for Parasitology: Parasites and Wildlife 6 (3), pp. 278-286 : 281

3.1. Infection with Sarcocystis spp .

Overall Sarcocystis spp . prevalence was 63.3% in hunting dogs from wolf areas and 65.5% in hunting dogs from control areas. In the dataset, 109 operational taxonomic units (OTUs) were detected ( Table 2) which were aligned to 11 Sarcocystis species ( Fig. 1 ). In 22.5% (wolf area) and 37.9% (control area) of all hunting dogs, OTUs were assigned to unknown Sarcocystis sp.

For general Sarcocystis prevalence (GLM, overall log likelihood ratio test, χ 2 = 14.280, df = 4, n = 78, p = 0.003) no significant difference was detected between study sites (p = 0.556), although prevalence significantly increased with sampling effort (p = 0.004) and significantly decreased with dog age (p = 0.014). Similarly, for Sarcocystis species richness (GLM, overall log likelihood ratio test, χ 2 = 17.965, df = 4, n = 78, p <0.001) no significant difference was detected between study sites (p = 0.380), although species richness significantly increased with increasing number of analysed samples (p <0.001) and significantly decreased with dog age (p = 0.013). In contrast, an infection with S. grueneri (GLM, overall log likelihood ratio test, χ 2 = 8.088, df = 4, n = 78, p = 0.044, Fig. 1 ) was significantly more likely to occur in hunting dogs sharing their habitat with wolves than in hunting dogs from control areas (p = 0.035), while sampling effort (p = 0.779) and dog age (p = 0.157) had no significant effect. For infections with S. taeniata no significant effect for any of the predictors was detected (GLM, overall log likelihood ratio test, χ 2 = 2.500, df = 4, n = 78, p = 0.476).

Figures

Fig. 1. Normalized Sarcocystis spp. prevalence in hunting dogs from the wolf area (dark grey, n = 49) and control area without wolves (light grey, n = 29). Hunting dogs were infected with 11 distinct Sarcocystis species, of which two species only occurred in wolf inhabited areas. They were significantly more likely to be infected with the ‘wolf- ‾specialized’ parasite S. grueneri when sharing their habitat with wolves (p = 0.035). It was not possible to determine a correlation for an infection with the other ‘wolf specialist’ S. taeniata and wolf presence (n.s. = not significant, p = 0.476). P values were extracted from GLMs.