Animal rights protesters appear to have caused £10,000 worth of damage at a West Lothian dog track, police said.
Police said an "immense" amount of damage had been caused
Paint was daubed on buildings, vehicles damaged and electric cables cut at the Armadale Greyhound Stadium between 1100 BST on Sunday and 0600 BST on Monday.
Lothian and Borders Police said the graffiti suggested the involvement of animal rights activists.
Police have also been investigating incidents at a deer farm last week and a Lanarkshire fishery on Sunday.
Explaining what happened at the dog track, a Lothian and Borders Police spokeswoman said: "There has been an immense amount of damage caused, and there is evidence to suggest that it may be related to animal activists.
"We would appeal to anyone who saw or heard anything suspicious to contact us immediately."
Last Wednesday, a Fife deer park was targeted, with slogans daubed on the farm property.
The owners of Reediehill deer farm in Auchtermuchty expressed shock at the incident.
Stella Fletcher said she and her parents Nicola, 54, and John, 59, discovered the damage on Thursday morning.
Ms Fletcher, 28, said the letters, "ALF", standing for the Animal Liberation Front, were painted on their property.
Strathclyde Police said enquiries were continuing into an alleged attack on Newmill trout fishery near Lanark.
The owners said that more than one mile of fencing had been cut down and 10 deer escaped.
The business kept 18 deer as a visitor attraction after the deer farm closed six years ago.
The owners said that the remaining eight had to be shot because of concerns that they could escape and be involved in road accidents.