Work

Performance deficits in SRLV-infected sheep quantify progressive disease severity

Year: 2026

Type: article

Abstract: Managing Maedi-Visna in sheep flocks infected by Small Ruminant Lentivirus (SRLV) by limiting production losses and reducing transmission could be a more cost-effective approach than eliminating the disease. We quantified the progressive physiological costs of SRLV infection by analysing performance measures as readily accessible criteria of disease severity in data from a five-year study of a Polish flock with bi-annual tests of serostatus. SRLV infection had no effect on ewes' pre-natal reproductive traits but caused increased mortality and reduced growth rate in their lambs, and reduced ewes' productive lifespan and output. These performance deficits were negligible soon after seroconversion but increased significantly with time since seroconversion, such that they became substantial in older ewes with longer durations of infection. We argue that infectiousness is likely to be correlated with disease severity and therefore tends to increase with the duration of infection, implying that the oldest animals pose the greatest infection risk. Selective culling of under-performing older ewes would limit ongoing production losses and may also reduce disease transmission in affected sheep flocks.

Source: Preventive Veterinary Medicine

DOI: 10.1016/j.prevetmed.2026.106878

Authors: Andrew W. Illius, Andrzej Junkuszew, Paulina Nazar, Nicholas J. Savill

Institutions: University of Edinburgh, University of Life Sciences in Lublin

Language: English

Topic: Infectious Diseases and Mycology

Subfield: Small Animals

Field: Veterinary

Domain: Health Sciences

SDGs: Zero hunger, Good health and well-being

Open Access status: hybrid

Estimated APC paid: $3,280