The helminth fauna of the house mouse (Mus musculus Linnaeus, 1758) was studied on the basis of 429 host individuals from the suburban area of Belgrade. Eleven helminth species were recorded: three cestode species - Catenotaenia pusilla, Rodentolepis fraterna, and Cysticercus (= Strobilocercus) fasciolaris [larval stage of Taenia taeniaeformis (Batsch, 1821)]; and eight nematode species - Heligmosomoides polygyrus, Syphacia sp., Aspiculuris tetraptera, Syphacia obvelata, Heterakis spumosa, Trichuris muris, Mastophorus muris, and Gongylonema sp. Within the general helminth fauna, H. polygyrus was found to be the most prevalent species (39.2%) and caused the highest infection intensity. Prevalences of A. tetraptera, C. pusilla, and S. obvelata ranged from 12.8% to 6.1%, while the remaining species showed prevalences ranging from 4.9% (for Syphacia sp.) to 0.2% (for Gongylonema sp.). All the species found in males were also present in females, with the exceptions of M. muris and Gongylonema sp. No significant differences were found between males and females regarding prevalence (P%), mean infection intensity (MI), or mean abundance (MA)

Basic immune-related health-relevant changes (total and differential white blood cell counts and activity, leukocyte tissue infiltration, and related pathohistology) were assessed in wild Norway rats from urban habitats. Comparative measurements were conducted in individuals of several laboratory strains of Norway rat in order to gain insight into environmental effects on the health of wild rats. Changes in leukocyte counts and activity along with tissue infiltration were noted only in wild rats, indicating systemic as well as tissue inflammation in these animals. Coincidence of these changes with chronic inflammatory pulmonary and kidney disease was observed in the majority of affected rats