Selective culling and the potential persistence of lumpy skin disease in cattle herds: insights from a mechanistic transmission model

The first epidemic of lumpy skin disease (LSD) in France started in June 2025, with a total of 117 outbreaks recorded. This vector-borne disease affecting cattle is highly contagious, and prompted the implementation of strict control measures, including total depopulation of affected herds, resulting in the culling of more than 3,500 cattle. During the epidemic, total depopulation measures became increasingly unacceptable to cattle farmers, as they were perceived as unnecessary, leading to major protests. We use mathematical models to compare within-herd transmission dynamics under a selective culling strategy versus total depopulation. In this work, we propose a compartmental model of within-herd transmission, accounting for both cattle and vector populations. A test-and-cull strategy is implemented, relying on imperfect diagnostic tests capable of detecting infection in asymptomatic cattle, and different levels of test sensitivity and detection earliness are investigated. Alongside the test-and-cull strategy, a vector control strategy is implemented considering different levels of effectiveness in reducing the vector population. Our model shows that a selective culling strategy still results in 75% [26, 100] of the herd becoming infected, even in the best-case-scenario with highly efficient diagnostic tests and vector control. Given currently available tests, considered to have a sensitivity of 30% for subclinical animals within 2-3 days prior to their infectiousness onset, the predicted persistence is 60 days [34, 95], with 94% of the herd [44, 100] eventually becoming infected, representing only a marginal advantage compared with a total depopulation strategy. These metrics further deteriorate when the efficacy of insecticide products decreases.