Gastrointestinal nematodes in ostriches, Struthio camelus, in different regions of the state of Rio de Janeiro, Brazil / Nematoides gastrintestinais em avestruzes, Struthio camelus, de diferentes regiões do Estado do Rio de Janeiro, Brasil

The ratite group is composed of ostriches, rheas, emus, cassowaries and kiwis. Little research has been done on parasitism in these birds. The aim of this study was to determine the distribution of infections by gastrointestinal nematodes in ostriches in the state of Rio de Janeiro. For this, fecal samples were collected from 192 on 13 farms. From each sample, four grams of feces were used to determine the eggs per gram of feces (EPG) count, by means of the McMaster technique. Part of the feces sample was used for fecal cultures, to identify 100 larvae per sample. The results were subjected to descriptive central trend and dispersion analysis, using confidence intervals at the 5% error probability level in accordance with the Student t distribution, and Tukey’s test with a 95% confidence interval. The mean EPG in the state was 1,557, and the municipality of Três Rios had the lowest average (62). The city of Campos dos Goytacazes presented the highest mean EPG of all the municipalities analyzed. The northern region presented the highest mean EPG, followed by the southern, metropolitan, coastal lowland and central regions. Libyostrongylus species were observed on all the farms: L. douglassii predominated, followed by L. dentatus and Codiostomum struthionis. .

O grupo das ratitas é composto pelas avestruzes, emas, emús, cassuares e kiwi. São poucas as pesquisas sobre as parasitoses nessas aves. O objetivo deste estudo foi determinar a distribuição de infecções por nematóides gastrintestinais em avestruzes no Estado do Rio de Janeiro. Para tanto, foram coletadas amostras fecais de 192 avestruzes de 13 propriedades. De cada amostra, quatro gramas foram utilizados para a contagem de ovos por grama de fezes (OPG), pela da técnica de McMaster. Parte das fezes foi utilizada para cultivos fecais para identificação de 100 larvas por amostra. Os resultados foram submetidos à análise descritiva de tendência central e de dispersão, utilizando-se o intervalo de confiança ao nível de 5% de probabilidade de erro de acordo com a distribuição t de Student e teste de Tukey com intervalo de confiança de 95%. A média de OPG no Estado foi de 1.557, e o município de Três Rios obteve a menor média (62). A cidade de Campos dos Goytacazes teve a maior média de OPG de todos os municípios analisados. A Região Norte teve a maior média de OPG, seguida das regiões Sul, Metropolitana, Baixada Litorânea e Central. As espécies de Libyostrongylus foram observadas em todas as propriedades, predominando L. douglassii, seguido de L. dentatus e Codiostomum struthionis.

Population dynamics of Libyostrongylus dentatus and L. douglassii of ostriches raised in the Northern Rio de Janeiro State, Brazil.

Libyostrongylus genus contains three species of gastrointestinal nematodes that infect ostriches. Of these, only Libyostrongylus douglassii has been implicated in diseases and lower productivity. A morphological diagnosis method allowing the discrimination of infective larvae of L. douglassii and Libyostrongylus dentatus and the evaluation of eggs per gram of feces (EPG) was used to determine the population dynamics of both species from two ostrich farms located in the northern region of the state of Rio de Janeiro, Brazil. The presence of these nematodes was monitored every 15 days for two years. The average EPG was 4631 and 587 on farms 1 and 2, respectively. Overall, the highest values of EPG were associated with the rainy season on both farms. However, only on farm 1 the rainy season correlated statistically with EPG. Both species of Libyostrongylus occurred on both farms with a higher predominance (86%) of L. douglassii on farm 1, whereas the distribution of infection on farm 2 was more heterogeneous with a slight predominance of L. douglassii. The infection and the prevalence of these species may vary considerably according to the farm facilities, management adopted, and season.