The mystery white powder behind an animal safety alert which closed a Hounslow park has been confirmed as flour.
It is believed to have been used by runners to mark their routes, as getwestlondon previously reported, but the council says it is unclear who was responsible.
The flour was found on the park's paths and play areas, and the council said its parks contractor Carillion had been washing the remaining mess away.
A council spokeswoman said notices would now be placed at all entrances to the park prohibiting the use of route markers unless authorised in advance by Carillion.
She added that Carillion would encourage all personal trainers, race organisers and other groups using the park to register with the contractor so it could provide them with guidelines.
A dog walker told getwestlondon one of the animals taken ill had been repeatedly vomiting on the day the powder was discovered but had since recovered.