Transitory lameness in sheep due to Hyalomma spp. infestation in Urmia, Iran

A total number of 457 Makui sheep were examined because of lameness in one or more limbs. Clinical examination of the affected flocks revealed heavy tick infestation on their limbs. Hosts usually had only one aggregate of ticks on each limb. Attachment of two or more ticks on the pastern caused non-weight bearing lameness in the lambs. Lameness was more prevalent (17%) in lambs than adults (3.5%). Hyalomma anatolicum anatolicum and H. asiaticum asiaticum were the most prevalent species detected on all affected animals. Heavy infestation of the hosts with these ticks could be the main cause of lameness. One aggregate of the ticks caused lameness in lambs. It is likely that considerable tissue damage caused by long mouthparts of the ticks and inflammatory reaction could lead to lameness. © 2005 Elsevier B.V. All rights reserved.