will hair grow back

My cat shadow had alot of mats on his stomach fur, I finally got rid of them but now he has bald spots, will the hair grow back in or did I take too much off when I combed him: as I had to realley pull to get them out, any input would be appreciated, thank you, shadow's mum

It might take a while but hair should grow back - just keep on brushing to avoud those nasty matts !!