A dog killed two lambs and injured two more belonging to a Stroud farmer on Saturday.
The dog “ripped out two of the animals’ throats,” broke the leg of another and gave the fourth a neck wound yesterday morning in Standish Park farm.
The attack has cost tenant farmers Jonathan and Annabelle Crump between £200 and £300.
“We haven’t had lambs killed like this before,” said Mr Crump, who has farmed the land near Haresfield beacon for 12 years.
“I was very fed up and cross. The worst thing is some dog has gone off now and might come back and do it again.”
Mr Crump found the lambs at midday on Saturday while performing a daily sheep check.
“The dog had been and gone so there was nothing you could do. Sometimes we catch the dog in the act but we didn’t on this occasion sadly.”
He said farming near Haresfield Beacon, a popular dog-walking spot, means that attacks can happen up to six times a year.
“Dog walkers should very well know the requirements and if a dog is caught it could be shot,” he said.
Mr Crump said he intends to report the incident to police today.