Dogs need to be brushed and bathed regularly to prevent the build-up of dirt and debris in their fur. Additionally, they need to be kept clean to prevent skin infections and other health problems. Overall, cats are generally considered to be cleaner than dogs because they groom themselves more frequently.

From a self-maintenance perspective, cats are generally considered cleaner than dogs because they spend up to 50% of their waking hours grooming themselves. Their tongues are covered in tiny barbs (papillae) that act as a natural comb, removing loose fur, parasites, and debris while spreading natural oils. Furthermore, cats are instinctively "fastidious" about their waste, almost always using a litter box and burying their scent to avoid predators. Dogs, by contrast, lack this intensive self-cleaning instinct and often enjoy rolling in "scent markers" like mud or grass, which they then track into the home. However, "clean" is relative; in 2026, veterinarians point out that while cats look cleaner, their litter boxes can harbor bacteria and dust, and their saliva contains allergens that are more potent than dog dander for many humans. While a dog requires more frequent "human-assisted" bathing to stay fresh, a cat is a self-contained cleaning machine that rarely requires a bath unless they are elderly or a hairless breed.