Azizi S, Tehrani A-A, Dalir-Naghadeh B, Hemmati M
Department of Clinical Sciences, Faculty of Veterinary Medicine, Urmia University, PO Box 57153-1177, Urmia, Iran.
N Z Vet J. 2011 Nov;59(6):311-6. doi: 10.1080/00480169.2011.609478.
To determine the prevalence of lameness in sheep in Urmia, northwest Iran, and compare the effects of production system and season on prevalence.
A cross-sectional study, using cluster sampling, was conducted. The selected flocks included 18 with 2,315 sheep from farmed production and 28 with 7,619 sheep from semi-migratory systems, and were visited once in summer (grazing season) and once in winter (housing season). Sheep showing signs of lameness were examined to detect the causes of lameness. Bacteriology and histopathology were also performed if required.
The probability of overall lameness was not affected by farming system (p = 0.40), but in the grazing season was less (OR = 0.62; 95% CI = 0.56-0.69) than in the housing season. Footrot was most the common cause of lameness, occurring in 1,047/1,880 (56%) cases. Among flocks, 40/46 (87%) had ≥ 1 case of footrot. Farming system had no effect on occurrence of footrot (p = 0.85), but the probability of footrot in the grazing season was less (OR = 0.21; 95% CI = 0.18-0.25) than in the housing season. Semi-migratory flocks had less hoof overgrowth (OR = 0.30; 95% CI = 0.16-0.56) than farmed flocks, and the probability of hoof overgrowth in the grazing season was less (OR = 0.19; 95% CI = 0.12-0.29) than in the housing season. The probability of digital abscess was less in semi-migratory flocks (OR = 0.64; 95% CI = 0.46-0.88) than farmed flocks, and in the grazing season was more (OR = 2.14; 95 CI = 1.61-2.85) than in the housing season. The probability of interdigital gland infection was higher (OR = 7.15; 95% CI = 5.36-9.55) in the grazing season than in the housing season. Staphylococcus aureus was isolated from 9/11 (82%) sheep affected with interdigital gland infection.
Footrot was the main cause of lameness in sheep in both farmed and semi-migratory farming systems in this study, especially in the housing season. In the grazing season, digital abscess and interdigital gland infection should be considered as common causes of sporadic lameness in sheep.
In practice, lameness in sheep can be a major concern both in farmed and semi-migratory farming systems, with a high occurrence in the housing season. Footrot was a main cause of lameness in sheep in northwest Iran.
确定伊朗西北部乌尔米耶地区绵羊跛行的患病率，并比较生产系统和季节对患病率的影响。
采用整群抽样进行横断面研究。所选羊群包括18个养殖生产系统的羊群，共2315只羊，以及28个半游牧系统的羊群，共7619只羊，在夏季（放牧季节）和冬季（圈养季节）各走访一次。对表现出跛行迹象的绵羊进行检查以确定跛行原因。必要时还进行了细菌学和组织病理学检查。
总体跛行的概率不受养殖系统影响（p = 0.40），但在放牧季节低于（比值比[OR]=0.62；95%置信区间[CI]=0.56 - 0.69）圈养季节。腐蹄病是跛行最常见的原因，在1880例病例中有1047例（56%）发生。在羊群中，40/46（87%）有≥1例腐蹄病。养殖系统对腐蹄病的发生没有影响（p = 0.85），但腐蹄病在放牧季节的概率低于（OR = 0.21；95% CI = 0.18 - 0.25）圈养季节。半游牧羊群的蹄过度生长情况少于（OR = 0.30；95% CI = 0.16 - 0.56）养殖羊群，且蹄过度生长在放牧季节的概率低于（OR = 0.19；95% CI = 0.12 - 0.29）圈养季节。半游牧羊群趾间脓肿的概率低于（OR = 0.64；95% CI = 0.46 - 0.88）养殖羊群，而在放牧季节高于（OR = 2.14；95% CI = 1.61 - 2.85）圈养季节。放牧季节趾间腺感染的概率高于（OR = 7.15；95% CI = 5.36 - 9.55）圈养季节。从9/11（82%）例受趾间腺感染的绵羊中分离出金黄色葡萄球菌。
在本研究中，腐蹄病是养殖和半游牧养殖系统中绵羊跛行的主要原因，尤其是在圈养季节。在放牧季节，趾间脓肿和趾间腺感染应被视为绵羊散发性跛行的常见原因。
在实际中，绵羊跛行在养殖和半游牧养殖系统中都可能是一个主要问题，在圈养季节发生率较高。腐蹄病是伊朗西北部绵羊跛行的主要原因。
