The cat has been called the "desert animal" because it needs very little water to survive. Because it consumes so very little water, its urine is very concentrated. And its diet is mainly meat, its urine tends to have a strong odor. So a good litter is very important. The litter should be both absorbent and deodorizing and, since it must not be dangerous to humans or cats, should not contain poison or powders. Most litter on the market today is made of clay. The litter box should be made of plastic (wood retains odors) and should be large enough to hold the cat comfortably. It should be at least 4 inches deep and the litter itself should be about 1.5 inches deep in the tray. This will permit liquids to be absorbed and the cat can bury the solid waste out of sight.
Of the commercial products, dust-free litters are best. With all commercial litters, solid wastes become covered with fine particles, which quickly dry the stools and lock the odors. This is especially true of clumping litter. It has sand-like granules of absorbing ground clay that dries and completely absorbs a cat's liquid wastes. You won't have to change the litter so often if droppings are removed daily. You can do this with a slotted litter scoop. The box itself should be disinfected regularly, but be careful to choose a disinfectant that is safe for cats. Avoid any with carbolic acid.
Plant-based deodorant powders are now available too. The powder, which can be placed under the layer of litter, both deodorizes and perfumes the air, making life more pleasant for cat owners. However, a few cats may be slightly offended by some perfumes and refuse to use their litter. Scented litters, too, should be used carefully for the same reason.
Sand and gravel are not good litter material because they are neither absorbent nor deodorizing. They also promote bacterial growth and so are potentially dangerous for both humans and cats.
Sawdust is also unacceptable since it clings to the cat's fur, and the animal may ingest large quantities of it when it grooms. Another concern is the type of wood that created the sawdust. Some woods are treated with chemicals that can be poisonous or allergenic.
Newspapers, too, should be avoided. The chemicals in the ink may interact with the urine to produce dangerous gases. Cats are very finicky about their litter box.They quickly become accustomed to one type of litter, and often insist on staying with the litter they used as kittens for the rest of their lives.
Cats are generally very clean. If a cat goes to the toilet outside the litter box, it almost certainly has some kind of problem, and is letting the owner know. The odor may be new and offensive to the cat, or the litter may not be fresh. Sometimes a cat will also avoid using its litter box if somebody has teased it or handled it roughly or if it has been disturbed while in the litter. Cats are very private animals. There are washable and recyclable litters. The granules are spread in a raised box which allows the urine to pass through while trapping the slid waste. After the waste is removed, the granules can be washed with tap water and used again.