Even though cats are wonderful pets to have around, they can also be rather annoying sometimes, with their bad behaviors (Especially if they start avoiding the litter box).
The whole house would get stinky and you will be getting enough with cleaning and washing the floor.
So, it is very important for a cat owner to know how to retrain the litter box just in case, a cat may starts avoiding the box.
A cat may start avoiding the litter box for several reasons 1.
The cat is stressed 2.
The box is not big enough anymore 3.
The box is dirty 4.
It doesn't like new cat litter type 5.
Injury in paws, and hard to dig litter (this usually happens with newly de-clawed cats, when they dig litter their paws hurt, so, they associate pain with the box and avoid it) Whatever the case, you first have to find it and solve the problem before trying to retrain the cat.
Isolate the cat in a quite and nearly empty room.
A water dish and a litter box (the water dish must be minimum five feet away from the box), a hiding place (an empty card board box would be fine) and something to sleep are to be the only items in the room(ideally).
Keep your cat for minimum three days in this room.
Everyday, enter the room, and feed the cat after cleaning the box.
You can play with you pet if you like, but don't take him out yet.
After three days, if he uses the box, you can let the cat go into another room where there is another box.
If possible don't let him wander here and there in the house yet.
If it eliminates outside the box again, after being let out, put him in again for couple of days.
If it eliminates in the same area clean it thoroughly or keep it away from the area.
Praise him every time it uses the box.
Don't ever punish as it could make him more stressed.
With patience, flexibility and praises, you will be able to retrain your cat fast.