1) Departamento de Microbiología e Parasitología. Universidade Federal de Santa Maria. 97.119-900.
Santa Maria. RS. Brasil. 2) Inspetoria Veterinaria - D. Pedrito RS. Brasil

Nematodes intestinales de perros callejeros como agentes de zoonosis en la ciudad de D. Pedrito (RS-Brasil).

La prevalencia de nematodes intestinales en perros fue el objetivo de esta investigación, principalmente debido al riego de zoonosis. Fueran analizadas heces de 65 perros aleatoriamente capturados en las calles de la ciudad de D. Pedrito (RS-Brasil). En 43 (66,2%) del total de las muestras analizadas, fueran encontrados huevos de nematodes intestinales, como sigue: Toxocara sp. 1 (1,5%), Ancylostoma sp. 30 (46,2%), Trichuris sp. 6 (9,2%), Ancylostoma sp. / Trichuris sp. 4 (6,2%) y Ancylostoma sp. / Toxocara sp. 2 (3,0%). Los resultados indican alta prevalencia de animales infectados lo que posibilita una posterior contaminación ambiental que es un un serio factor de riesgo para seres humanos.

Key words (Palabras clave): nematodes; dogs (perros); zoonosis; D. Pedrito (RS-Brazil).

Stray dogs have a very important role in dissemination of virus, bacteria and parasites, which can affect human beings due to their capacity as zoonoses agents (Jucket, 1997; Tan, 1997). Contamination of public areas with parasites eggs have been investigated by some workers in Latin America (Mienville et al., 1993; Torno Cafasso et al., 1996; Vasquez Tsuji et al., 1996). In Brazil, this epidemiological aspect was also investigated to show to the population who lives in the community some diseases that can be disseminated by dogs (Alcantara et al., 1989; Oliveira et al., 1990; Correa, 1995).

In all the above-mentioned references, it can be observed differences in the prevalence of intestinal parasites in dogs, according to the studied region and local influences. This way, the aim of the present project was to verify what kind of nematodes are found in stray dogs from D. Pedrito city which belongs to a characteristic region in Rio Grande do Sul state known as "campanha" and is located in the Uruguayan border and where rural activities have the main economical importance.

Feces from 65 dogs were analyzed. All material was obtained by purgation with 5 ml of arecoline bromhidrate (1,5% V/V), according to previous report (Schantz, 1973). Feces were analyzed as soon as possible by the Willis technique (Lapage, 1965).

In the analyzed feces was found that 66% (43/65) of them were positive for nematodes eggs (Table I).

In can be observed a high prevalence of infected dogs with Nematodae. Among them, Ancylostoma sp. plays the mayor role (36 cases). In some animals this parasite was found associated with Toxocara sp. (4 cases) or with Trichuris sp. (2 cases). In six dogs only Trichuris sp. was found and in one, only Toxocara sp. eggs.

It is common to find in the literature reports about the prevalence of Nematodae in dogs due to the zoonosis risk like larva migrans or other kind of parasitism (Alcantara et al, 1989; Oliveira et al., 1990; Mienville et al., 1993; Torno Cafasso et al., 1996; Vasquez Tsuji et al., 1996).

In Rio Grande do Sul State, not much has been done to avoid zoonoses transmitted by dogs and prevalence data are seldom found. A recent study (Correa, 1995) showed that in 93.3% of urban squares of a city in the same state, eggs of dogs Nematodae were found, suggesting that environmental contamination may be a serious risk for humans, mainly for children. In this report, a high prevalence of these parasites was found and soil contamination may occur.

The present work didn't pretend to analyze the whole sum of biological possibilities, but more than this present local data and this way stress that local communities must have a constant control over dogs, mainly stray dogs, to avoid human parasitoses with sometimes a bad prognosis.

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