For more than 80 years the bronze Dog on the Tuckerbox has been sitting obediently as tourists visit the Australian icon.

However on Sunday morning, visitors and residents were "devastated" to find the dog had been knocked into the well.

The site's current leaseholder Denny Allnutt said this low act was not welcome in the community.

"I'm absolutely gutted and really devastated; it's so tragic to see the dog being the target of such a nasty sense of vandalism," she said.

"Visitors are shocked and saddened and we would've had about 100 people come today who are disappointed to find it like this, especially those who have traveled a long way."

Ms Allnutt's lease ends on Wednesday and said this tragedy could impact the new leaseholder's future plans.

"This will hugely impact her as we don't know at this stage if the dog will be repaired by the time the site opens again on August 10," she said.

"The dog's ears have broken off and the historic old wishing well, made of fragile sandstone, has been damaged; the dog can be repaired, but the well can't be.

"The new leaseholder has got great plans for the side and it was all on track, but suddenly there is potentially no dog."

The dog was famously stolen in 1981 by a group of Canberra university students as part of a prank.

"The dog was well looked after and then handed into Collingullie Police Station, but this was nothing like that," Ms Allnutt said.

"I'm sure the dog will be back on his tuckerbox and will remain there for years to come."

The Cootamundra Gundagai Council are working with the Riverina Police District to find those responsible.