El Khalfaoui Nora, El Amiri Bouchra, Rahim Abdellatif, Chentouf Mouad, Raes Marianne, Marcotty Tanguy, Kirschvink Nathalie
Namur Research Institute for Life Sciences NARILIS, University of Namur, 5000 Namur, Belgium.
Animal Production Unit, Regional Center Agricultural Research of Settat, National Institute for Agricultural Research (INRA), Avenue Ennasr, P.O. Box 415, Rabat Principal, Rabat 10090, Morocco.
Animals (Basel). 2024 Dec 17;14(24):3641. doi: 10.3390/ani14243641.
Caseous lymphadenitis is an infectious disease that has a significant economic impact on sheep breeding. The objectives of this study were to evaluate the effect of season, animals' age, sex, body score and shearing on the clinical incidence of caseous lymphadenitis, relapses and abscess location in sheep from Settat province, Morocco. In this longitudinal study, 274 clinically healthy sheep were recruited in six flocks among 1451 inspected sheep and followed during 12 months to cover four seasons. The animals involved in this study were assigned to different age categories at continuous recruitment from February to July 2021 (lambs younger than 6 months, young sheep between 6 and 24 months and old sheep more than 24 months) and to sex categories. Selected animals were clinically examined every 2 months to detect superficial abscesses by palpation of superficial lymph nodes. Information about the number of abscesses and their locations was recorded and analyzed in multivariable statistical models. The results showed that 185/274 (67.5%) of the monitored animals developed superficial CL abscesses. The risk ratio (RR) of superficial CL was significantly higher between April and September compared to between January and March (RR~4.4; < 0.0001). No significant difference was found between October and December compared to between January and March (RR = 1.2; = 0.64). Regarding the effect of age, the results revealed that the RR was significantly lower in old sheep compared to lambs (RR = 0.45, < 0.0001). No significant difference was detected between lambs and young sheep (RR = 0.7, = 0.07). The prevalence of caudally located abscesses (prefemoral and popliteal lymph nodes, as well as in testicles, scrotum and mammary glands) was significantly higher in old sheep than in lambs (20% versus 3%; odds ratio = 7.8, = 0.02). The sex, body score and shearing since the last examination did not show any significant effect on CL incidence ( > 0.1). Abscess relapse was significantly lower in old sheep than in lambs (IRR = 0.4, = 0.003). The highest clinical CL incidence was observed in young animals between April and September and was likely due to indoor intensive rearing management. To conclude, both season and age had significant effects on superficial CL incidence. Farmers, veterinarians and technicians should focus attention and preventive measures against CL on young animals during spring and summer.
干酪性淋巴结炎是一种对绵羊养殖有重大经济影响的传染病。本研究的目的是评估季节、动物年龄、性别、体况评分和剪毛对摩洛哥塞塔特省绵羊干酪性淋巴结炎临床发病率、复发情况及脓肿位置的影响。在这项纵向研究中，从1451只受检绵羊的6个羊群中招募了274只临床健康的绵羊，并在12个月内进行跟踪，以涵盖四个季节。在2021年2月至7月连续招募过程中，参与本研究的动物被分为不同年龄组（6个月以下的羔羊、6至24个月的青年羊和24个月以上的成年羊）和性别组。每2个月对选定的动物进行一次临床检查，通过触诊浅表淋巴结来检测浅表脓肿。记录脓肿数量及其位置的信息，并在多变量统计模型中进行分析。结果显示，185/274（67.5%）的受监测动物出现了浅表性干酪性淋巴结炎脓肿。与1月至3月相比，4月至9月浅表性干酪性淋巴结炎的风险比（RR）显著更高（RR~4.4；<0.0001）。与1月至3月相比，10月至12月未发现显著差异（RR = 1.2；= 0.64）。关于年龄的影响，结果显示成年羊的RR显著低于羔羊（RR = 0.45，<0.0001）。羔羊和青年羊之间未检测到显著差异（RR = 0.7，= 0.07）。成年羊尾侧位置脓肿（股前和腘淋巴结以及睾丸、阴囊和乳腺）的患病率显著高于羔羊（20%对3%；优势比 = 7.8，= 0.02）。性别、体况评分和上次检查后的剪毛对干酪性淋巴结炎发病率未显示出任何显著影响（>0.1）。成年羊的脓肿复发率显著低于羔羊（发病率比 = 0.4，= 0.003）。4月至9月期间，幼龄动物的临床干酪性淋巴结炎发病率最高，这可能归因于室内密集饲养管理。总之，季节和年龄对浅表性干酪性淋巴结炎发病率均有显著影响。养殖户、兽医和技术人员应在春季和夏季重点关注幼龄动物，并采取针对干酪性淋巴结炎的预防措施。
