Risk factors for tick attachment to smallholder dairy cattle in Tanzania N.H. Ogden a, * , E. Swai b , G. Beauchamp a , E. Karimuribo c , J.L. Fitzpatrick d , M.J. Bryant e , D. Kambarage c , N.P. French f a Groupe de Recherche en E ´ pide´miologie et Sante´ Publique, De´partement de Pathologie et Microbiologie, Faculte´ de Me´decine Ve´te´rinaire, Universite´ de Montre´al C.P. 5000, Saint-Hyacinthe, Que. J2S 7C6, Canada b Tanga Dairy Development Programme, Tanga, Tanzania c Faculty of Veterinary Medicine, Sokoine University of Agriculture, Morogoro, Tanzania d The Moredun Research Institute, Penicuik, Midlothian, UK e Department of Agriculture, University of Reading, UK f Department of Veterinary Clinical Science, University of Liverpool, S. Wirral, UK Received 23 June 2003; received in revised form 24 September 2004; accepted 14 October 2004 Abstract A cross-sectional study was conducted in Tanga and Iringa regions of Tanzania, and a longitudinal study in Tanga, to investigate tick-control methods and other factors influencing tick attachment to the cattle of smallholder dairy farms. Most farmers reported applying acaricides at intervals of 1–2 weeks, most used acaricides that require on-farm dilution and most farmers incorrectly diluted the acaricides. Rhipicephalus appendiculatus and Boophilus spp. ticks were those most-frequently encountered on the cattle, but few cattle carried ticks of any species (only 13 and 4.6% of tick counts of the cattle yielded adult R. appendiculatus and Boophilus spp., respectively). Animals were more likely to carry one or more adult Boophilus spp. ticks if they also carried one or more R. appendiculatus adults (OR = 14.4, CI = 9.2, 22.5). The use of pour-on acaricides was associated with lower odds that animals carried a R. appendiculatus tick (OR = 0.29, CI = 0.18, 0.49) but higher odds that they carried a Boophilus spp. tick (OR = 2.48, CI = 1.55, 3.97). Animals >4 months old and those with a recent history of grazing had higher odds of carrying either a R. appendiculatus (ORs = 3.41 and 2.58, CIs = 2.34, 4.98 and 1.80, 3.71), or a Boophilus spp. tick (ORs = 5.70 and 2.18, CIs = 2.34, 4.98 and 1.49. 3.25), but zero-grazing management did not prevent ticks attaching to www.elsevier.com/locate/prevetmed Preventive Veterinary Medicine 67 (2005) 157–170 * Corresponding author. Tel.: +1 450 773 8521x8643; fax: +1 450 778 8120. E-mail address: nicholas.ogden@umontreal.ca (N.H. Ogden). 0167-5877/$ – see front matter # 2004 Elsevier B.V. All rights reserved. doi:10.1016/j.prevetmed.2004.10.011