A dog suffered serious injuries and needed emergency surgery after being mauled by a deer in Ampthill Park.
Shelagh Dixon, of Lea Road, Ampthill, was walking her two-year-old Jack Russell, Gussie, in the wooded area of the park on Thursday when the attack happened.
Gussie suffered two serious gashes, which run along the length of her body, and needed extensive surgery costing £600.
Mrs Dixon said: "Gussie was in a very sorry state.
"The problem has not gone away and will never go away. Little dogs in the park should not be let off the lead, it's not safe.
"I thought it would just be in spring when the muntjac are mating, but apparently they now mate 12 months a year. They're breeding like fury."
The Times & Citizen reported on Ampthill Park's problems with muntjac deer attacking dogs in August.
Vet John Wakely, from John Wakely and Associates in Flitwick, treated Gussie following the attack.
And he said he has grave concerns about the park.
Mr Wakely said: "Last autumn, we had a spate of attacks and then they came back in spring when we had another spate of maybe 15 dogs.
"They come in with these multiple slashes and the presumption, and it is probably a pretty good one, is that it is a deer causing them.
"They are really deep, potentially life-threatening wounds or gashes and it is only a matter of time before a dog gets killed."
Gussie is the second dog Mr Wakely has treated for wounds received in Ampthill Park in the last 10 days.
Muntjac deer have been roaming in Ampthill Park since the 1920s.
They are the only deer species in the UK to have small horns, and not antlers.
The male muntjacs have sharp fang-like tusks that grow up to 2.5in (6cm), which they use to fight rivals that set foot in their territory.
Mrs Dixon added: "My concern is people should know the problem has not gone away.
"Secondly, the vet bills are very expensive and if somebody does not have pet insurance or the money to pay for surgery it could lead to the dog being put down."
Ampthill Town Council have now put up signs in the park warning dog owners to keep their pets on a lead near the wooded area.
The BedfordToday files:
Don't mess with those Muntjac!