New kitten, and litter box question

We have had one kitten for a few months. He is finally done with all his shots and has had pills for worms and what not. Well I wanted to get him a friend so we got a little 7 week old yesterday. They play together sometimes, but my bigger cat gets a little rough so I'm trying to keep them separated for a bit. I have 2 different litter boxes and I'm trying to keep them apart so they don't share until the new kitten is wormed. Is there anyway to encourage them to use their own? Or should I just keep them apart till the kitten is fully treated?

Good luck trying to keep them in separate litter boxes. I would call the vet and explain and ask if you can bring a stool sample by. Watch for new kitty to go and then scoop it up immediately so you know it is hers. Keep it well wrapped and deliver to vets soon as possible, then you won't have to worry. Keep it in fridge till you go. I know it sounds gross. but keep it away from other fridge contents,  Good Luck. Enjoy your furbabies.

Well I have realized we have to keep them separate for awhile anyway. I thought it would be easier to get them to get along since hey are both young. But my older kitten keeps pouncing on the little one and then tries to bite on him like he does his toys. I think the under one is just so tiny, he is confused by it. I'm switching out who is in the one room and who gets to roam the house, I let them see each other a little bit, and I will hold the smaller one in my lap and play with the bigger one. Hopefully once the little one gets bigger they will be able to play nice.