Epidemiological observations on lungworm, Dictyocaulus arnfieldi, in donkeys from Morocco.

Regular monthly examination of lungs of donkeys, with a total of 423 in a year, revealed that in Morocco Dictyocaulus arnfieldi infection is present throughout the year with an annual incidence of 47.8% (range 30 to 62.2%). The monthly mean number of worms per animal varied from 19.4 to 69.6 (annual average 39.5) with a maximum of 1000 worms in a donkey. October, February and June are the months when peaks of infections were observed. The ratio of worms in lungs to larvae per g in faeces (L.P.G.) ratio varied from 1:0.57 to 1:1.33 (average 1:0.97) and although this relation was significant, cases with high worm burden and no larvae in faeces were observed.