Frequence of infection by Giardia lamblia (Kunstler, 1882) in dogs (Canis familiaris) available trough the Faust and Collaborators Method (1939) and Auramine Staining in Canoas, RS, Brazil

Giardia lamblia is a protozoan that commonly infects young animals which live in groups. Despite its high prevalence many animals don’t exhibit clinical signs. Giardiasis is epidemiologically important concerning the zoonotic potential of the disease. The objective of this study was to determine the frequence of Giardia lamblia in the canine population of Canoas, RS, Brazil, applying the Faust and Collaborators Method (1939) and the Auramine Staining Technique. The dogs were classified according to the origin and gender. Feces samples of 332 dogs were analyzed by the Faust and Collaborators Method. The frequency of the infection obtained was 34.04%, ranging from 28.95% to 39.13% (confident interval at a 95% level). For kennel bred animals 40,96% of the samples were positive and for stray dogs 27.11%. Applying Fisher’s Exact Test to these figures there was a significant difference (P=0.0107) when comparing the origin of the animals and the results of the tests. However when comparing genders there was no significant difference (P=0.8162), the former with 33.11% of positive males and 34.08% positive females. When submitted to the Auramine Staining Technique(147 samples), 15.67% (23) of the samples resulted positive. The statistical analysis using the McNemar Test exposed a significant difference between both techniques (P=0.0004). The Kappa value of 0.07 obtained was considered of low rate. The results allow one to affirm that the Faust and Collaborators Method was the most suitable diagnostic test for Giardia lamblia infection, considering the high prevalence of this parasite in the studied region.

Giardia lamblia; dogs; Canoas; Faust and collaborators method; Auramina staining; diagnostic; frequence


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