Observation on the age at initial infection of Zebu Calves by Toxocara vitulorum in Northern Nigeria

A study was carried out to determine the mode of infection of neonatal zebu calves by Toxocara vitulorum in Northern Nigeria under both the extensively nomadic and the semi-intensively Institutional or Private Managements. Of the 90 calves from the 12 nomadic and 70 calves from the 8 Institutional/Private herds sampled, 20 and 10 respectively were positive for Toxocara (Neoascaris) vitulorum eggs in their faeces by the age of one week. This is a strong indication of the early infection of zebu calves by T. vitulorum, in Northern Nigeria as reported for calves of similar ages in other countries. This early infections could have been through intra-uterine route or postnatally via colostrum. Some of the calves voided mature stages of the helminth in their faeces between the ages of 7 and 8 weeks, which might be suggestive of either prenatal (intra-uterine) or postnatal (intra-mammary) modes of infections. Also, an infection rate among the calves of 91.1% for the nomadic and 61.4% for the Institutional/Private farms were observed in this study. The implications of these findings for the success of the cattle industry in Nigeria are discussed. Key Words: Toxocara vitulorum, neonatal zebu-calves; Initial age of infection. Trop. Vet. Vol. 21: (3) 124-128 (2003)