Three alpacas were mauled to death at a Stanwell Tops country retreat last weekend, while a mobile phone camera captured the frightening picture of a deer using a swimming pool to save itself from being attacked last week.

The image, posted as a warning on a Facebook page for residents in the 2508 postcode on Tuesday, was taken on a property on Otford Road between Otford and Helensburgh. 

‘‘Does anyone recognise this dog?,’’ the post read. 

A woman who lives at the property told the Mercury she’d never seen anything like it before.

‘‘We’ve been here 15 years and nothing has gone in that pool ... I think we’ve had a black snake in there and that’s it,’’  the woman, who wanted to remain anonymous, said. 

‘‘Although we’ve had feral deer around and National Parks [and Wildlife] culling them and things like that, it’s more the fact that this dog came chasing after blood.’’ 

The woman said the roaming dog had chased the deer through a chook pen and a 1.5-metre fence before it ended up in the pool. 

‘‘I didn’t know anything about that until I heard a noise crashing down next to the house,’’ she said.

‘‘When I went downstairs ... I heard the splash in the pool and saw that [the dog and the deer].’’

The woman told her elderly mother-in-law to stay inside the house with the family’s small dog and alerted her husband. He was able to scare the dog away and the frightened deer removed itself from the pool after about 10 minutes.

‘‘If a dog is chasing a deer with that much viciousness, you worry about children and small dogs and elderly people,’’ the woman said.

The sentiment was echoed by Geoffrey Pybus, the owner of Wagon Wheels Country Retreat at Stanwell Tops, who lost three of his beloved pet alpacas at the weekend.

‘‘The alpacas were just wandering around in the paddock and we heard a bit of barking about 3 o’clock in the morning,’’ he said.

‘‘When we went down in the daylight, three alpacas were strewn across the path ... [they were] very savaged.’’

Mr Pybus said he hadn’t seen any dogs prior to the attack, but believed there were three ‘‘fairly big’’ dogs roaming the area.

‘‘They appeared and they disappeared and so did our alpacas,’’ he said. 

The alpacas - which have been with him for about eight years - had tried to save themselves by running around, Mr Pybus said.

The harmless animals were no match for the dogs and suffered fatal injuries to their groin, neck and forearms. 

Mr Pybus had feared for two ponies, a donkey, horses and the people who lease a house on his land.

‘‘There’s three young two-year-olds on this property, so we’re a bit worried about that ... they can savage adults too. We’re all just very distressed and fearful of the future,’’ he said.

A council spokesman said the organisation had received a report of the alpaca incident.

‘‘There were no witnesses and it is unclear if it was domestic or feral dogs involved,’’ the spokesman said.

‘‘Council and NSW Police have been notified of this incident by the owner of the alpacas. Council rangers also regularly patrol the area between Helensburgh and Stanwell Park looking for roaming dogs.

‘‘If there are members of the public that have information, we urge them to contact Council on 4227 7111 so that we can continue with the investigation into this attack.’’