How can i fix the rubber on the side of my double glazed Windows?

We rent a 1 bedroom flat, and have double glazed windows fitted in. We also have 2 house cats and the combination doesn't mix well. When they see something outside they stand on the back paws and claw at the side of the windows and over time the rubber is shredded and bits of this rubber are coming away from the side.
As we are moving out soon we would like are full deposit back so what is the best way to fix this as cheap as possible?

Thanks in advanced!