Work

Clinical, epidemiological, pathological features and molecular analysis of sheep-associated malignant catarrhal fever infection in cattle in Rio Grande do Sul, Brazil

Year: 2026

Type: article

Abstract: ABSTRACT: Malignant catarrhal fever (MCF) is a severe, multisystemic, and usually fatal disease. In Brazil, MCF is frequently diagnosed in cattle and associated with OvHV-2. This study described the clinical and epidemiological characteristics, necropsy findings, and genetic identification of OvHV-2. Two outbreaks of MCF were identified in cattle in the western region of Rio Grande do Sul, Brazil, where only one animal was affected on each farm. The clinical signs observed were apathy, anorexia, bilateral corneal opacity, motor incoordination, decubitus, and pedaling movements. Macroscopic alterations included secretions and crusts in the nasal and ocular regions, the udder and vulva, and corneal opacity. Molecular analysis confirmed the wide distribution of OvHV-2 in the tissues of the affected animals. Sequencing of the amplified fragment showed that the two samples are genetically similar to others identified in cattle, grouping them with viruses of North American and Brazilian origin. The findings contribute to our knowledge of the disease and the molecular identity of the samples in the two outbreaks diagnosed.

Source: Ciência Rural

DOI: 10.1590/0103-8478cr20250150