Why has my cat suddenly developed the Worst Breath Ever?

Dear Sinéad, Siouxsie and Thomas:
I have a cat that we found a few years ago. He is about 10 now. He stays indoors. He has the most horrible breath that we have ever smelled. Unfortunately, when he grooms himself, he transfers the smell to his fur. He has a good personality and very soft fur. The kids love him, but the smell may force us to give him up. The breath problem only started about 3 months ago. There were no changes to his diet or to anything else in the house. Please help!

Thank you!
~Peter and Adora

Sinéad: Well, Peter and Adora, there are several reasons your cat could have developed bad breath, and all of them merit a trip to the veterinarian to see what's going on.

Siouxsie: Before you call the vet, though, take some time to figure out what you're going to tell your vet. You will need to be able to describe the odor and tell your vet if there are any times when the odor gets worse or better.

Thomas: That's right. Sometimes the type of bad breath odor can give a vet valuable diagnostic clues.

Sinéad: Our top two guesses for your cat's breath problem are an infection in your cat's mouth, sinuses or tonsils; or a chronic condition such as diabetes or kidney disease.

Siouxsie: If your cat's breath has a sickly-sweet smell to it, like sugar and/or acetone, your cat may have diabetes. Other symptoms of diabetes include excessive thirst, excessive urination, weight loss along with constant hunger, and (in severe cases, if the blood sugar levels get too high or low), collapse.

Thomas: If your cat's breath smells sort of like urine or ammonia, that might be a signal that his kidneys are damaged and not functioning as well as they should.

Sinéad: If your cat's breath smells like something died in his mouth, that probably means he's got an infected tooth or gum disease. Cats can develop a type of cavity called a resorptive lesion. These usually appear along the gum line. Take a look at your cat's teeth and gums. Are his gums red and swollen, and does his mouth seem sore to the touch? If so, he needs to go to the vet to have his teeth cleaned and perhaps have antibiotics.

Siouxsie: Infections of the sinuses, tonsils and other areas close to the mouth can also cause bad breath. This bad breath will smell sort of like pus.

Thomas: Whatever the cause of your cat's stinky breath, it definitely merits a trip to the vet. At 10 years old, your cat is now a senior citizen, and at this time of his life he may begin to develop chronic, age-related diseases such as arthritis, hyperthyroidism, and tumors. A checkup will give you peace of mind and an understanding of what's going on in your cat's body.

Sinéad: If your cat has gum disease and needs to have his teeth cleaned, your vet will do this procedure with your cat under anesthesia. We would recommend that you opt for a pre-anesthetic blood test so that your vet will know whether your cat's liver, kidneys, heart and other organs are functioning properly, whether your cat is anemic and if he is fighting off some sort of infection. Because anesthetics and other chemicals are removed from the body through the liver and kidneys, it's vital that these organs be functioning properly to avoid complications.

Siouxsie: Sinéad and I are going to be 10 this year, too, and although we're healthy, Mama says that if one of us needed to have an operation, she'd spend the extra money on a blood test just to be on the safe side.

Thomas: Speaking of blood tests, if your vet does a physical exam on Mister Stinky-Breath and finds anything out of the ordinary -- for example, weight loss, a mass in the abdomen, his or her own assessment of the breath smells -- he or she will probably order a blood test at that time, too.

Sinéad: Other diagnostic tests such as an ultrasound exam or an X-ray may also be done on your kitty if any abnormalities are found. I had an ultrasound once. Mama brought me to the vet because I wasn't feeling good, the vet saw that I'd lost weight and took an X-ray and saw that my liver was enlarged. Then she ran a blood test and found out that my liver enzyme levels were elevated, and she sent Mama and me to another clinic where they did the ultrasound test. By that time I was starting to feel better because Mama had been giving me antibiotics and a nutraceutical called Denosyl, and my ultrasound came back almost all clear.

Siouxsie: And she came back with her whole tummy shaved. Hee hee hee!

Sinéad: Hey, it's not funny! I was cold! And groggy because they gave me some medicine to make me relax.

Siouxsie: Aw, heck. I'm just glad you were okay.

Thomas: So, Peter and Adora, what we're saying in a nutshell is that you really need to get your cat to the vet and see if he or she can find out why his breath is so bad. There are plenty of ways to treat bad breath. If it's his teeth, he may have to have a few pulled out. He may have to take antibiotics for a while if he has an infection. And even if he's got some kind of chronic health condition, there's every reason to believe he can have a good life for many years to come.

Sinéad: If your cat does have to take antibiotics, we recommend that you feed him a tablespoon or so a day of plain (unflavored), organic, lowfat yogurt with active cultures during the course of his treatment. This will help keep him from developing diarrhea as a result of the antibiotics killing the good bacteria in his intestines. It may help sweeten his breath, too.

Siouxsie: If your vet can't find anything medically wrong with your cat, consider consulting a holistic veterinarian. A holistic vet may be able to help you establish a nutrition program and prescribe herbal or homeopathic remedies to help your cat restore his system to full health -- and his breath to full sweetness.

Thomas: We hope this information helps you and your kitty. We've written another article on bad breath in cats, in which we elaborate more on holistic care and how it can address these issues; maybe you'll want to check it out. Please let us know how your kitty is doing.

Got a question? Need some advice? E-mail us at None of the material in this column is meant to be a substitute for regular veterinary care.