Dog owners in North Yorkshire are being warned to stay away from Burton Riggs Nature reserve at Seamer, Scarborough after three dogs died only minutes after being in the area.
Notices warning of the potential risk have been put up by the Yorkshire Wildlife Trust.
This warning follows the deaths of eight dogs after ingesting poison on a footpath in Crosshills, Keighley.
The RSPCA have said that at the moment the two sets of deaths were not being linked. Anyone with information has been asked to contact the RSPCA