Bad breath, medically termed halitosis, is a “common problem in cats,” says Tufts veterinary internist Michael Stone, DVM, and can be severe enough to “create problems in the animal-owner relationship.” For sure, it’s hard to get up close and personal with a cat whose breath smells worse than fishy.
But bad breath isn’t simply unpleasant. It may mean there’s a health problem that needs to be addressed.
Most of the time, that problem has to do with an issue in or near the mouth. “In about 90 percent of patients, the origin of halitosis is within the oral cavity,” Dr. Stone says. Periodontal, or gum, disease is the most common cause, he reports. Dental plaque and the bacterial process that causes it can lead to an awful odor without routine dental care. Other causes of bad breath originating in the mouth include infections, ulcerations, tumors, and foreign material.
An infection, tumor, or foreign material in the nasal and sinus passages can also be the origin of foul odor. Food retained in the esophagus can cause halitosis, too.
Sometimes, though, halitosis arises from an underlying disease process rather than one occurring right in a cat’s mouth. Depending on which disease, the odor will take on its own quality. That is, certain compounds will break down and produce a scent that points to a specific cause. The chemical process that occurs inside your pet’s body could end up smelling sulfurous, fruity, or ammonia-like depending on what is going awry.
Bear in mind that a certain odor can never be used to diagnose a disease on its own. There are always other signs, and you should take a cat with disagreeable breath to the veterinarian for a clinical exam and potentially a laboratory work-up to to get a proper diagnosis and treatment, especially since the signs of different diseases can overlap. But bad breath can be the (smelly) canary in the coal mine, so to speak. Herein, a rundown of scents that correlate to specific diseases.
Matching the odor to the health problem
-Fruity breath. A fruity scent coming from your cat’s mouth can signal diabetes. The cause of the fruity quality to the breath is acetone. Acetone is the smallest and simplest ketone, which is created by the liver when breaking down fat. In cats with diabetes, acetone is metabolized instead of sugar—and this process is what produces the fruity smell.
Other diabetes signs: increased thirst, frequent urination, weight loss without any decrease in appetite.
-Urine- or ammonia-like breath. One of the breakdown products of metabolism, urea, passes through the kidneys and is then passed in the urine. But if a cat has kidney disease, some urea is instead let out when a cat exhales. Hence the urine-like scent.
Other kidney disease signs: increased urination, increased thirst, decreased appetite.
-Musty, foul breath. When the liver is unable to do its job of filtering toxic substances, sulfur-smelling dimethyl sulfide makes its way to the lungs, and a cat will emit a musty and foul breath referred to in medical terminology as fetor hepaticus. Translation: breath of the dead. This actually occurs in advanced stages of the disease. Other signs appear earlier.
Other liver disease signs: decreased appetite, weight loss, jaundice (yellowing) of the white of eyes, gums, or skin, depressed energy or mood.
-Morning breathe, 24/7. Periodontal disease is the most common cause of consistent and persistent bad breath in cats, although other causes may include infections, ulcerations, tumors, and foreign material.
Other periodontal disease signs: difficulty eating, red or swollen gums, pawing at her own face.