IL PARASSITISMO GASTROINTESTINALE NELLA CAPRA DA LATTE: ASPETTI EPIDEMIOLOGICI, RICADUTE SULLE PRODUZIONI E PROBLEMATICHE DI FARMACORESISTENZA NEGLI ALLEVAMENTI LOMBARDI

Gastrointesinal parasites are wide present in dairy goat breeding and they still represent a peculiar healthy problem, in all kinds of management and in every geographical area. Data obtained during the three years of Ph.D. shows that gastrointestinal nematodes infections are extremely common in goats farmed in Lombardy Region (P = 96%, 95% CI: 95,1- 96,7%); taxa causing infection are numerous. In particular, the aim of our study was to perform an evaluation of drug resistance to anthelmintic compounds in dairy goats in Lombardy Region: breed condition, management an frequency of treatment all represents well described risk factors for this kind of phenomenon. The study has been performed in grazing flocks and farms with semi-intensive management, where exposure to nematodes infective larvae present in the environment is wide. Overall the study has involved 1228 animals (treated and controls). The goal was the survey of anthelmintic resistance to different drugs: it was performed using FECRT (fecal egg count reduction test) following WAAP (World Association for the Advancement of Veterinary Parasitology) guideline. This test produce a percentage value which represents drug effectiveness. Furthermore fecal cultures from fecal pools (pre- and post-treatment) were prepared to isolate and identify larval nematodes genera resistant to drug treatment. According to FECRT value, farms were classified in different groups. Similar classification was performed for a macrocyclic lactone drug. FECRT value was obtained for every treated animal; extrapolation for the entire flocks was calculated (excluding animals with low level of eggs excretion: <150 UPG). Most of the tested animals were sensible (FECRT > 90%) to benzimidazoles and pro-benzimidazoles drugs; a drug resistance was suspected in 3 farms (FECRT < 90% but > 67%); only one farm was BZ-average resistant. Finally, a collection of gastrointestinal nematodes larvae was realized to attempt a bio-molecular approach in testing drug resistance.