Two Staffordshire bull terriers were put down after an horrific attack on two foals at stables in Worton on Sunday.
Christopher Davies, 54, who runs Southcroft Stables with his mother Jean, witnessed the attack on Fifi and Spot shortly before midday.
He was filling haynets in the barn when he was alerted to activity in the neighbouring paddock.
He said: “I saw a black thing with red legs galloping across the field and I realised it was Fifi with blood gushing down her legs.”
Mr Davies was horrified to see two dogs hanging off Fifi as she galloped along. He vaulted a five-bar gate into the field.
He said: “I saw a two-foot tree branch on the grass, picked it up and hit the dog, which was hanging on to her nose, several times until it let go.”
Eventually the dogs ran off leaving the foals in a terrible condition.
Vet Carina Palmer from The Paddock Veterinary Practice in Eastcott was summoned and worked on the injured horses for over four hours.
Fifi required 80 stitches in wounds on her legs, sides and face while Spot needed 20 stitches in a gaping wound on her muzzle.
The vets bills are expected to top £2,000.
Mr Davies, a professional show producer who has competed at the Royal International Horse Show among other prestigious events, said the attack will affect the foals’ futures.
He said: “We would expect Fifi to compete at the Horse of the Year show but she might have a nasty scar that will ruin her showing career.”
The owner of the dogs, who lives close by but has not been named by police, is said to be distraught at the injuries caused by the dogs.
He asked police to have them put down. He may still face prosecution over the incident.
Mrs Davies, whose family has operated the stables for over 30 years, said: “I don’t know the man but he was very upset.
“Although there have been incidents of dogs attacking horses and cattle around the area, it has never happened to us before.
“The foals were a terrible sight to see. They are still very nervous and I don’t know if they will ever get over this.”