Abstract
Nematode infections pose a threat to backyard chickens, presenting serious health and productivity challenges. The study aimed to assess risk factors related to pathological changes and the effect of mebendazole and its derivatives against nematode infections in domestic chickens. A total of 456 chicken faecal samples were randomly collected and analysed using the direct smear, flotation methods and sedimentation method, and histopathological analysis was performed. Sixty infected chickens were divided into three groups: X (control), Y (mebendazole), and Z (derivative), treated orally at 10 mg/kg for three days. Data were analyzed in R (v2025) to compute percentages, 95 % CIs, p-values, and odds ratios. Overall, 72 % (330/456) of chickens were infected, with nematode parasite, Ascaridia galli, being the most prevalent species, 38.5 % (127/330). Single infections were the most common 70.3 % (232/330), followed by double infections 24.5 % (81/330), and triple infections 5.2 % (17/330). Infections were more common during the wet season 65 % (215/330) and were higher in females 74.6 % (200/267), young 85 % (233/274), and weak chickens 90.6 % (126/139), free-range systems 74.3 % (255/355) and non-dewormed chickens 73.3 % (262/356). Multivariate logistic analysis showed significant associations (p < 0.05) with age, gender body condition, and management type, Histopathological alterations revealed hemorrhagic enteritis, necrotic patches, intestinal inflammation, submucosal oedema, glandular hyperplasia and villous atrophy. Anthelmintic trials demonstrated that both Mebendazole and its derivative significantly reduced the eggs per gram (EPG) of faecal samples of roundworm, with the derivative being more effective. Nematode infections cause significant health problems and economic losses in poultry; therefore, improved management, sanitation, and regular deworming practices are essential to effectively control parasitic infections in domestic chickens.