Police have ruled out foul play after three dogs died and at least seven more became ill after drinking from a lake in Dartford.
A Kent Police spokesman said there is nothing to suggest "anything sinister", adding that no criminal offences have been disclosed.
Police warned people to stay away from Brooklands Lake, near Powder Mill Lane, which will remain closed for at least a week as authorities try to determine the cause of the illnesses.
Dartford Borough Council and the Environment Agency (EA) will press on with the investigation.
Police cordoned off parts of the lake after a dog walker said three of her animals became ill and later died after going into the lake.
Parkvets Veterinary Hospital in Footscray, Sidcup, said it knew of a total of 10 dogs that have been affected, including the three that died. The surviving dogs are being kept under observation.