Kieran Best, dog control officer for Stratford District Council, says such attacks are "few and far between", with the last reported incident in September last year.
The Lehmanns are taking no chances that it will happen to them again, and are investing in deer fencing for the property. Diane says the fencing is expensive, "but then, so are the alpacas, and there is no price on the emotional attachment we have to our animals".
They have also put up signs warning they will shoot roaming dogs on the property.
"We have had no problems with dogs before, but we are not going to allow this to happen again."
Kieran says that under the Dog Control Act 1996, the Lehmanns are within their rights to do so as owners of stock or poultry.
Soon after the attack, the Lehmanns called Stratford District Council to report it to dog control. The call went to Armourguard which covers night and weekend shifts for dog control, and its officer came out to investigate; however, the dogs were long gone.
Kieran reminds dog owners of their responsibilities to ensure dogs are confined or under direct control from half an hour after sunset each day until half an hour before sunrise the next day. He says dogs can cover a large area and travel long distances across country when on the loose.