The seven include three persons from a housing complex here and a labourer, officials informed.
Police said that a resident of the housing complex had filed a complaint that a group of people had objected to her feeding dogs in the vicinity of the complex.
The complainant told police that on January 14, around 8:30pm, this group of seven people beat up four puppies and put them in a sack and abandoned them near a crematorium here.
The complainant further told police that when she went to check on the puppies, she found that one of them had died due to the assault.
He added that investigations were underway but no arrests had been made so far.