Prevalence of gastrointestinal parasites in small ruminants in Grenada, West Indies

Abstract

Economic losses and adverse effects on animals' health and productivity due to gastrointestinal parasites constitute a significant challenge for expanding and improving the small ruminant industry in developing countries. This study aimed to determine the diversity and geographic distribution of gastrointestinal parasites infecting small ruminants in Grenada. Seven hundred and thirteen fecal samples from 159 sheep and 554 goats from 64 farms in Grenada, Carriacou, and Petite Martinique were collected for coprological examination. Of 713 sheep and goat samples, 640 were positive for gastrointestinal parasites, yielding an overall prevalence of 90 % (CI 95%, 88 to 92 %). Of the 554 goat samples, 95 % were positive for parasites (525/554; CI 95%, 93 to 97 %), and for the 159 sheep, 72 % were positive (115/159; CI 95%, 65 to 79 %). In goats, the most common parasites observed were Strongyles, 90 % (CI95%, 87 to 92 %); Eimeria spp., 50 % (CI95%, 46 to 54 %); Strongyloides, 7 % (CI95%, 5 to 9 %); Moniezia, 6 % (CI95%, 5 to 9 %); and Trichuris, 5% (CI95%, 4 to 7 %). Sheep showed a similar pattern with the most common parasites identified being Strongyles, 52 % (CI95%, 44 to 59 %); Eimeria spp., 50 % (CI95%, 42 to 57 %); Strongyloides, 6 % (CI95%, 3 to 11 %); Moniezia, 6 % (CI95%, 3 to 10 %); and Trichuris, 3 % (CI95%, 1 to 7 %). The overall prevalence of gastrointestinal nematode (GIN) infections was higher in goats (p < 0.0001), due to the higher prevalence of Strongyles. The proportion of goats with zero parasites was significantly less than the proportion of sheep (p < 0.0001). Larval identification using coproculture analysis performed on pooled fecal samples from each farm to determine the GIN percentages and the overall mean indicated that Haemonchus was the most common genus identified, with an overall mean of 56 %, followed by Trichostrongylus (31 %), Oesophagostomum (13 %) and Cooperia (0.1 %). Nemabiome analysis based on deep amplicon sequencing demonstrated the presence of six nematode species: Haemonchus contortus (42 %), Trichostrongylus colubriformis (38 %), Oesophagostomum columbianum (12 %), Oesophagostomum asperum (7 %), Cooperia punctata (0.4 %) and Cooperia spatulata (0.1 %).