Congenital brain lesions in calves caused by bluetongue virus serotype 3 infection.

BTV-3 infection during bovine pregnancy can cause severe congenital brain lesions in calves, warranting BTV vaccination consideration.

This focus article from the Animal and Plant Health Agency (APHA) addresses congenital brain lesions identified in calves attributed to bluetongue virus serotype 3 (BTV-3) infection. Bluetongue is an arthropod-borne viral disease transmitted primarily by Culicoides midges, affecting ruminants including cattle, sheep, and goats. BTV-3, which emerged in northern Europe in 2023, has been associated with significant clinical disease in cattle, including reproductive consequences such as congenital defects. The article describes neurological abnormalities observed in calves born to dams infected with BTV-3 during pregnancy, consistent with in utero viral infection during critical developmental periods. Bluetongue virus is known to cross the placental barrier and cause fetal brain damage, particularly when infection occurs during organogenesis, resulting in lesions such as hydranencephaly, porencephaly, and cerebellar hypoplasia. These findings are clinically significant as affected calves may present with severe neurological deficits at birth, including blindness, inability to stand, opisthotonus, and poor suckle reflex, often necessitating euthanasia on welfare grounds. The article highlights the importance of recognizing BTV-3 as a differential diagnosis for congenital neurological disease in calves born in BTV-endemic or newly affected regions. Veterinary practitioners should consider BTV-3 vaccination strategies in breeding cattle and report suspected cases to regulatory authorities, given the notifiable status of bluetongue disease in the United Kingdom.

This summary was distilled by AI and may occasionally misinterpret data. Confirm critical details with the primary literature before clinical application.