EPIDEMIOLOGIC ASPECTS OF LUNGWORM INFECTIONS OF GOATS IN MOROCCO

The results of a survey of lungworm infections in goats in the Middle Atlas and Rabat areas in Morocco during 1990-1992 are reported. Five s pecies were recorded: Dictyocaulus filaria, Protostrongylus rufescens, Cystocaulus ocreatus, Muellerius capillaris and Neostrongylus lineari s, The parasitological profile of protostrongylid species was represen ted by Muellerius (69-78%), Protostrongylus (16-25%) and Cystocaulus ( 5-6%) in the Rabat and Middle Atlas areas, Neostrongylus was virtually non-existent (under 1%) in both regions. Multigeneric infection invol ving several species of lungworms reached 54% in Rabat and 88% in Midd le Atlas. Dictyocaulus infection of goats does not appear to be a seri ous problem. Infection rates of 40% and 50%, and average worm burdens of three and five worms per kid and adult goat were recorded in autumn in the Rabat area. A similar pattern was noted in Middle Atlas. In co ntrast, the incidence of small lungworm infections in goats is widespr ead at levels likely to be of economic significance, The level of infe ction was considerably higher than the Dictyocaulus infection and the infection rate was virtually 100% in both age groups in the two areas. The overall worm burdens averaged 77.03 +/- 22.6 parasites per adult goat and 44.16 +/- 16.3 per kid in the Rabat area, whereas the corresp onding figures in Middle Atlas were 51.48 +/- 16.65 and 34.06 +/- 2.69 worms. The periods of high risk of infection by small lungworms were autumn, early winter and late spring-early summer. However, the heavie st infection by adult worms and the highest larval excretion were obse rved in late autumn and winter when molluscs were heavily infected. Th e periparturient period seemed to exert a positive influence on protos trongylid larval production. The output of first stage larvae (L(1)) o f lungworms was significantly higher in goats than in sheep. Thus, goa ts may play a greater role in pasture contamination. The epidemiologic al factors influencing the seasonal fluctuations of lungworms are disc ussed and a timetable of recommended treatments is suggested.