Giardia cysts were identified in 8.5 % of total dogs (52/614) and statistical significantly more frequently in dogs living in communities. The cysts prevalence according with dog populations was as follows: 7.2 % (9/125) in kennel dogs; 16.5 % (27/164 in shelter dogs; 4.3 % (2/46) in shepherd dogs; 4.8 % (4/84) in household dogs from urban areas; and 5.1 % (10/195) in household dogs from rural areas.
The overall prevalence of Giardia infection by ELISA was 34.6 % (144/416). The prevalence was significantly higher in kennel dogs (50 % ; 13/26), shelter dogs (47.7 % ; 74/155) and shepherd dogs (40.5 % ; 17/42) than in household dogs from urban areas (34.1 % ; 15/44) and household dogs from rural areas (16.8 % ; 25/149).
It was noticed poor agreement between microscopy and ELISA (k = 0.19). The microscopy performed best, with an Youden Index of 0.74, a Se of 73.68 % and a Sp of 100 % . ELISA had 100 % Sp, but only 19.44 % Se.
Young dogs (up to 12 months age) and living in communities were identified as risk factors for infection by multivariate logistic regression analysis.
71.2 % (37/52) Giardia cysts positive dogs presented co-infections with other intestinal parasites: Toxocara canis (14/52; 26.9 % ), Isospora ohioensis (12/52; 23.1 % ), Ancylostoma caninum (9/52; 17.3 % ), Uncinaria stenocephala (7/52; 13.5 % ), Trichocephalus vulpis (6/52; 11.5 % ), Hammondia heydorni/Neospora caninum (5/52; 9.6 % ), Sarcocystis spp. (5/52; 9.6 % ), Isospora canis (4/52; 7.7 % ), Capillaria aerophila (3/52; 5.8 % ), Strongyloides stercoralis (2/52; 93.8 % ), Dipylidium caninum (1/52; 1.9 % ) and Toxascaris leonina (1/52; 1.9 % ).