The dirt can affect plant life, officials said
Dog owners who fail to clean up after their pets in a Nottinghamshire nature reserve are to be shamed by having the dirt sprayed bright pink.
The scheme has been launched at Oak Tree Heath in Mansfield following persistent problems.
While fouling already carries a £50 fine, the district council said owners being responsible was a better option.
Volunteers will implement the scheme using a biodegradable dye designed for use on trees.
Officials said they had to act because the fouling - as well as being unsightly and a health threat - could affect plant life at the nature reserve.
Last year Mansfield District Council issued 136 fixed penalty notices for dog fouling.