If your cat is peeing in the tub instead of in his litter box, you're most likely not smiling. Before you decide to punish or scold him, ask yourself why he's resorting to this behavior. There might be a bigger problem at hand, and if you're not diligently cleaning the litter box, you might be to blame for his behavior.
Before trying to correct you finicky feline's behavior, rule out medical conditions by taking him to a veterinarian. Sometimes conditions such as kidney stones, diabetes or a urinary tract infection can result in inappropriate elimination. If urinating is painful to your cat, he might find the cool surface of the tub soothing and prefer to do his business there instead. Older cats might pee in the tub because they simply forget where the litter box is.
The Litter Box
If your cat is soiling the tub, his litter box might be to blame. If it's dirty, clean it more often, because it might be triggering his undesired behavior. Setting up several covered and uncovered litter boxes with different types of litter throughout quiet areas of the house can help determine your cat's preference. Always ensure that there's at least one more litter box than the number of cats you have. A tub-peeing cat who has a preference for a smooth surface might even prefer doing his business in an empty litter box.
In addition to making the litter box appealing to your cat, make the tub unappealing to him. Covering the bottom of the tub with an upside-down carpet runner or sheets of aluminum foil makes the surface unpleasant to stand on. Since cats won't eliminate in their play and feeding area, putting his toys or food in the tub can make him think twice about peeing in it. The easiest solution might just be to always leave 1 inch of water in the tub. When your cat jumps in the tub, the shallow water will quickly repel him.
If your cat is stressed, he might use the tub as his litter box. Stress can be triggered by different things, such as conflicts with other animals in the household, moving into another house or changes to your cat's daily routine. Maintaining a set schedule can prevent stress. A veterinarian might be able to prescribe medications to reduce stress in your cat or you can purchase synthetic pheromone sprays or diffusers that can help reduce your cat's stress.