I got a female lion head rabbit a couple of weeks ago, shes about7 or 8weeks old. When I first got her, her pee was normal but now its thick and yellow and smells really bad... Why is this?
Yikes, it sounds like she's dehydrated and/or she has a urinary tract infection.
Make sure she has both a water bowl and a water bottle. I'd also put a little cranberry juice in another bowl and see if she drinks it. If not, try another kind of juice. (Just a cap full or two).
She really needs fluids.
I'd get her to the vet ASAP, she may need fluids through a needle/infusion.
PS: If she's only seven or eight weeks old now and you've had her for a couple of weeks, she was probably taken away from her mom and siblings way too young and didn't have the time to build a good immune system. Where did you get her? I really would get her to a rabbit-experienced vet for some fluids and a urine test. Rabbits don't show their illnesses, they never *look* sick until they're very sick.