Hundreds of thumbtacks have been found in pet food left at an off-leash dog park in Ipswich.
The local council is offering a $5,000 reward to catch those responsible for placing the baits at Augustine Heights Dog Park near Springfield.
Acting Ipswich Mayor Paul Tully said a young couple had notified him of the concerning situation.
"I remain stunned," he said.
"I've been in local government for 38 years and I've seen other forms of vandalism like property damage, but never things that would harm defenceless animals.
"I'm appalled that someone could even put one thumbtack into an off-leash dog park.
"It's absolutely disgusting. These people are sick in the mind if they are doing this stuff."
'This is a disgraceful, deliberate attempt'
Mr Tully said the food was scattered across half a hectare of the dog park.
"It was a very deliberate attempt to spread the thumbtacks to cause maximum injury and damage to dogs that swallowed them," he told ABC Radio Brisbane's Emma Griffiths.
"It's disgraceful that human beings could hurt animals like this."
No dogs have been injured, but Mr Tully said he had also received an email from a parent regarding the tacks.
"The email told me their child had a tack on the edge of their shoe," he said.
It is hoped the cash reward will encourage local residents with knowledge about the incident to come forward.
"We need the information which would lead to the apprehension and conviction of those responsible, with a reward up to $5,000 depending on the information provided," Mr Tully said.
The council is confident that all the tacks have been removed from the park.
"I've done my own scout of the area as well and I'm 99.9 per cent sure we have the lot," Mr Tully said.
Anyone with information should call Ipswich City Council on 3810 6666.
