Efficacy of Fenbendazole against Gastrointestinal Nematodes in White-Tailed Deer

Abstract

We provided fenbendazole to captive (N q 77) and free-ranging (3 study areas) white-tailed deer (Odocoileus virginianus) in Louisiana to determine effects on gastrointestinal nematode burdens. Fenbendazole reduced gastrointestinal nematode burdens of captive and free-ranging white-tailed deer. Mean eggs per gram of feces from captive deer decreased P<O.Ol and P<O.Ol, respectively) 89% and 84% after provision of fenbendazole in doses approximating 0.47 and 0.62 g/deer, respectively. Doses approximating 0.42-0.46 g/deer did not affect (P = 0.61) eggs per gram of feces collected from free-ranging deer. Mean eggs per gram of feces collected from free-ranging deer was affected by fenbendazole treatment (P= 0.04) and decreased an average of 86% (SE = 1.9) on the 3 study areas after provision of fenbendazole in doses approximating 1.67-1.82 g/deer. Eggs per gram of feces collected from the distal colon and abomasal parasite counts from abomasa of freeranging deer harvested on the study areas were associated positively (r = 0.706, P<O.OOl), were affected by fenbendazole treatment (P<O.Ol andP<O.Ol, respectively), and decreased 66% (SE = 5.1) and 52% (SE = 7.4), respectively, after provision of fenbenda

Anthelmintic treatment affects behavioural time allocation in a free-ranging ungulate

“…First-stage lungworm larvae in faeces were measured using a beaker-modified Baermann method (Ezenwa et al, 2012;Forrester & Lankester, 1997). Although factors such as host faecal output rate and differential parasite fecundity can affect egg and larval counts, we used faecal egg and larval counts as a proxy of individual parasite loads based on other ungulate studies showing that faecal egg counts can provide an accurate estimate of adult worm burdens (Budischak et al, 2015;Cabaret et al, 1998;Grenfell et al, 1995;Irvine et al, 2001;Schultz et al, 1993). All samples were processed on the day of collection.…”