People in the area of Cross Hills, North Yorkshire, have been urged to take extra care when putting on their pooch's dog collar and lead and taking them out for a walk.
The RSPCA has asked owners be extra vigilant after a number of dogs died when walking along a specific footpath in the area.
Sally Ramsden, RSPCA animal welfare officer, said: "People are taking their dogs out along this footpath and within less than 20 minutes, the dogs are suffering convulsions and dying.
"We don't know what could be causing this but we strongly suspect that the dogs may have been poisoned. We also cannot rule out the possibility that this is being done deliberately."
She added that the RSPCA is asking owners in the area not to take their dogs on the footpath, which is located off Station Road.
The charity is currently working with North Yorkshire Police and Craven District Council to work out the cause of these deaths.