Prevalence and Morphometric Comparison of Trichostrongylus spp. among Sheep and Goats from Kashan Abattoir, Central Iran

Trichostrongyloiasis is a prevalent infection in humans and some animals worldwide. Morphology is a reliable tool for identifying Trichostrongylus species. This study aimed to determine the prevalence of Trichostrongylus infection in livestock and compare the morphometric characteristics of the species in sheep and goats referred to Kashan Abattoir, Iran, in 2018.

This cross-sectional study was performed on 130 goats and 154 sheep. The small intestine was collected from the slaughterhouse; the samples were opened and examined, and the genus and species of worms were identified based on morphological features reflected in diagnostic keys. Five morphometric indices, including body length and width, copulatory bursa width, shape length of the spicule, and gubernaculum length, were measured in 70 worm isolates. The data were analyzed using the ANOVA test in SPSS 18 software.

Of 284 livestock (130 goats and 154 sheep) examined, 26 (9/15%) were infected with Trichostrongylus. The prevalence of infection in goats and sheep was 12.3% and 6.5%, respectively. The most frequent species were Trichostrongylus colubriformis (48.7%), followed by Trichostrongylus vitrinus (25.7%). Trichostrongylus capricula and Trichostrongylus probolurus had an incidence of 12.8%. T. probolurus showed a higher length of spicule and gubernaculum, while T. vitrinus showed a wider copulatory bursa compared to the other species (P <0.001).

The prevalence of Trichostrongylus infection in this region was remarkable. Morphometric and morphological methods are practical tools in differentiating male Trichostrongylus species. However, in addition to morphometric studies, molecular methods are required to identify female worms, larvae, and eggs accurately.