A mare has been put down after being spooked by a firework set off nearby.
An RSPCA inspector and vet were called to the field in Overseal, Derbyshire, at 6.30am on 31 March following a call from concerned neighbours.
The owner, Kirsty Youart had heard the bang the previous night when she was at work 2 miles away.
The vet said Gracie, a 9-year-old rescue horse, had suffered a neurologic episode, probably caused by her galloping into another horse.
5 other horses in the field survived the incident, although Blaze, at 14hh cob had a fractured nose.
Ms Youart said the person responsible for letting off the firework should have given some warning to local horse owners.
She said: “You prepare yourself for bonfire night, but you don’t expect fireworks on Mother’s Day.
“We have people shooting right next to our field and we’ve never had an issue like this before.”