J. Cabaret et al., STUDIES ON MULTISPECIFIC RESISTANCE OF GASTROINTESTINAL NEMATODES TO BENZIMIDAZOLES ON DAIRY-GOAT FARMS, Veterinary parasitology, 60(3-4), 1995, pp. 331-337
Multispecific resistance to benzimidazoles was studied in three select
ed farms. These farms had bred dairy goats for more than 15 years. The
helminths were introduced with the goats at the establishment of the
farms which afterwards remained isolated. Nematode resistance could th
en be related to their own management practices. Faecal egg count test
s and egg hatch assays were performed to assess intensity of resistanc
e. The generic (infective larvae in faecal cultures) and specific rich
ness (adult worms) were assessed. The resistant species were Trichostr
ongylus colubriformis, Teladorsagia circumcincta, Haemonchus contortus
and Oesophagostomum venulosum. Faecal egg count reduction tests and e
gg-hatch assays did not match exactly. Faecal larval counts after trea
tments gave a distorted picture of multispecific resistance: Haemonchu
s and Oesophagostomum were very largely over represented. The number o
f species found in the three farms was relatively low compared with ot
her reports in goat farms of the area. This reduction of diversity mig
ht also be due in part to characteristics of breeding management and h
istory (use of permanent pasture and introduction of goats at the esta
blishment of farm).