WRITTEN BYJennifer Coates, DVM Veterinarian Dr. Jennifer Coates is an accomplished veterinarian, writer, editor, and consultant with years of experience in the fields of veterinary…,By Jennifer Coates, DVM When you think of smelly pets, cats aren’t the first species that come to mind. Cleanliness is one of their biggest draws, after all. So, if you start to detect a bad odor emanating from your cat, you need to take notice. In most cases, foul feline smells are a sign that something is seriously wrong. The best way for pet parents to start to determine what could be making their cats smell bad is to focus on the exact nature of the odor and where on the body it’s coming from. Mouth Odor A healthy feline mouth doesn’t stink, but a lot can go wrong to change that. Dental disease is the most common cause of unpleasant cat odors. Plaque and tartar accumulating on the teeth, gums becoming inflamed and separating from their underlying structures, and loose teeth all provide the perfect environment for bad breath. Food lodges in abnormal gum pockets and rots there, and bacterial infections that produce foul odors can proliferate in the unhealthy environment. Bad smells may also develop as a result of foreign material getting lodged in the mouth, trauma to oral tissues, and oral tumors. Sometimes systemic diseases will cause abnormal smelling breath. Most notably, kidney disease can lead to a urine or ammonia-like odor coming from the mouth. Diabetes mellitus may produce a sweet or “fruity” smell or, when a cat’s condition has worsened, an odor similar to nail polish. Cats with severe liver disease or an intestinal blockage may have breath that smells like feces.