A Comparative Study on Pathological Changes in the Small Intestine of Sheep and Goat Experimentally Infected with Trichostrongylus colubriformis .

Background: Trichostrongylus colubriformis , also called hairworm, is a genus of parasitic roundworm affecting gastro-intestinal tracts of a ruminant. Gross and microscopic lesion characterizations and comparing its effect in the small intestine of sheep and goats experimentally infected with T. colubriformis were undertaken in the study.
Methods: During the study period, 13 sheep and 14 goats were included in the experiment. The larvae of T. culibriformis were obtained from abattoirs and larvae were recovered by Bearmann techniques. The infective larvae of T. culibriformis (L3) as a single dose of 10,000 per-animal was administered orally to infected groups of sheep and goats. Blood was collected for hematological and serum biochemical analysis. Tissues for gross and histopathologic lesions characterization were collected from killed infected animals at 56 days.
Results: From the infected group, the total recovered mean worm burden was recorded as higher in goats ( P <0.05) than sheep, with an establishment rate of 50.16% and 34.46%, respectively. The total mean PCV, Hb, and albumin values recorded in the infected groups of sheep and goats were significantly ( P <0.05) lower than non-infected control of both animal groups. In goats, the total serum protein was significantly ( P <0.05) lower in the infected group than the non-infected control group. Gross lesions found were enteritis with petechial hemorrhages, edema, hyperemia, and mucosal slough, which were marked in the duodenum (62.69%) and jejunum (33.33%) in sheep and 47.05% duodenum and 45.09% jejunum in goats. The microscopic lesions developed by T. colubriformis were subtotal villus atrophy, hemorrhage, straightened and elongated dilated crypts, loss of epithelium, mucosal erosion, and infiltration of inflammatory cells.
Conclusion: The present study showed that T. colubriformis infection caused physiological and pathological changes of the small-intestine in sheep and goats, with more severe infection in goats than sheep, although they were under the same management condition.
Competing Interests: Dr Tamirat Kaba reports grants from Addis Ababa University, personal fees from Arba Minch University, during the conduct of the study. The authors declare that they have no other competing interests.
(© 2022 Tafere et al.)