'This stuff kills foals quicker than you can say Jack Robinson - it's lethal'

For the sharp-eyed, there were subtle signs splashed across social media this spring that a potentially lethal killer of foals was stalking through Kentucky’s Bluegrass and, as it turns out, likely in Europe and other global centres of breeding activity.

Photos of foalings taking place outside the snug safety of barns began appearing, even though the Kentucky spring was chilly and damp. More photos of mares and newborns contained in small outdoor paddocks or round pens were readily noticed.

These otherwise bucolic scenes were indications of an emerging war against a new virus that horse breeders may fear just as much as they did Covid when it was attacking people in waves. This virulent strain, identified as Rotavirus Group B, can infect a farm’s foals as quickly as dominoes falling in a board game, leaving extensive costs for treatment, or, worse, losses in its wake.