The 58-year-old female elephant, Bijlee, had collapsed last week in suburban Mulund due to weakness, said activist Ganesh Nayak, of the NGO, Animals Matter To Me.
Prior to that, she had fallen into a creek and injured her hind legs and suffering various problems ever since.
Bijlee had apparently been used during marriage ceremonies by the couple who own her.
"We brought in a veterinary doctor Kushal Sharma from Guwahati to treat the ailing female elephant. He specialises in treating elephants and is advising a medical team on how to continue treating Bijlee," Nayak said.
Bachchan took to tweeter to make an appeal to contribute for treatment and upkeep of the "gentle giant".
Nayak said Bijlee has been given proper medical treatment which will last eight days and none of her organs has been damaged. "Her blood count is also normal," he added.