Rough kitten paw pad

Noticed recently that my kitten (4 months M, working on finishing vaccines) has rough paws pads. It’s on both front paws same pad. I have 1 other cat (1.5 year old up to date on vaccine). What is it?

They share a litter box and eat the same food (Hills adult indoor) because when I had kitten food they both would constantly eat the wrong food :)

Thanks in advance!

https://imgur.com/a/NjvVJgx