My dog eats the cat poo...help!

I have a problem and I need help.  I have 2 5 year old cats and one 2 year old dog, all mixed breed.  The dog will not stay out of the litter box.  I clean the box once a day.  It has a lid on it but that does deter him.  I have read about stuff you put in the cat's food but it got mixed reviews.  Has anyone had this problem and how have you solved it?  I can't put the litter box in any other place so that is out.  I am at my wit's end, I am afraid the litter is going to clog him up or something...help!

Thanks!

Tami

My dog eats litter box tootsie rolls too.

My solution was to convert an old entertainment center cabinet into a litter box cabinet.

I installed a lock on the doors, cut a hole in the side just big enough for my largest cat, and the cabinet is close to a wall, with only a cat sized gap to allow access to the entrance.
 

I put a kitty door on our upstairs bathroom door.  The bathroom is big enough to house the litterboxes.   Problem went away after the dogs couldn't get in.  One cat hated going through the door so I put a small screw hook in the door on the bathroom side and wrapped a wire around it so I could leave it open. Can still unhook the wire in case I have to put a cat on lockdown for any reason (rare).

I use a big sterilite container as a litter box, and that keeps both my dogs out of the box, even without the lid. If yours is especially persistent, you could leave the lid on with a hole cut in it.