Both the dog and the tiger currently appear to be unharmed and steps were being taken to tranquilise the feline prior to taking it out of the pit, a senior forest official said.
Photographs aired on TV channels show both animals lying in the pit close to each other.
The information about the incident was received around 7am and forest personnel were immediately dispatched to the site which lies between the Tamil Nadu forest reserve and the Periyar sanctuary, the official said.
He also said that it was not an area where tigers were usually seen. PTI HMP HMP ROH