Plasma Cell Stomatitis

(also called “lymphoplasmacytic stomatitis” or
“LPS” or more correctly "Feline Caudal Stomatitis")

A general physical examination involves an inspection of the teeth and mouth, provided that the patient is of a cooperative nature. We see plaque build-up, tartar, missing teeth and all sorts of dental conditions that result from a lifetime of basically no toothbrush use (sadly, the norm for cats) but sometimes we see a very special type of gingivitis.

cat gingivitis

stomatitis mouth

The picture on the left shows a cat’s teeth and gums that are
affected with only minor periodontal disease. The cat on the right
has Plasma Cell Stomatitis. Note the red, irritated gums

The teeth usually do not look too bad but the gums are an angry red. They bleed at the slightest touch and sometimes there seem to be irritated proliferations growing from them. The breath stinks, the cat drools, and often the cat will hardly eat or will only lick the juices off canned foods. The irritation is most obvious in an area called the “fauce” which is the area in the back of the mouth where the upper and lower jaws come together. (Technically speaking this area is not the "fauce" but is actually the "palatoglossal fold" but the term "fauce" is still in common use.

A biopsy is needed to confirm the diagnosis but this is the characteristic appearance of “plasma cell stomatitis.” It is an extremely painful condition.


stomatitisSadly, we do not know how cats get this condition and until we do it will be hard to effect prevention. The condition does seem to result from an excessive immune reaction against the plaque that forms on the teeth or against the dentin making up the tooth itself.

There is an association with this condition and the Feline Immunodeficiency Virus as well as with Calicivirus infection. Further, there are metabolic causes of oral ulceration that can mimic plasma cell stomatitis. Cats suspected of having this condition require some metabolic screening (i.e. blood testing) including viral testing for FIV. A biopsy of the mouth is needed to confirm that the problem is actually plasma cell stomatitis and not something of similar appearance but requiring different treatment.


Stringent control of plaque is crucial to the management of these cats. Expect an affected cat to require teeth cleaning under general anesthesia every 6 months and possibly even more frequently than that. Home care in the form of mouthwashes or (if possible) brushing is also important but often not practical due to the oral pain.

Cortisone derivative medicines such as prednisone are often helpful in relieving the inflammation. Again, because of the pain, oral medication may be difficult to administer. A compounding pharmacy can be used to convert the tablet into a palatable liquid but often a long acting injection is needed to initiate treatment. Frequently, long-acting injectable steroids such as methylprednisolone acetate (Depomedrol®) are used with favorable responses generally observed within 1-2 days.

While the cortisone-type hormones are very helpful for the pain and inflammation, they may facilitate some of the bacteria that colonize the mouth. Bacterial infection often complicates plasma cell stomatitis so antibiotics such as clavamox or clindamycin are often prescribed, sometimes for long term use. These antibiotics are especially good for oral infections as they especially target anaerobic bacteria that live in the mineralized plaque covering the teeth. Other antibiotics that might be recommended include: metronidazole, doxycycline, and azithromycin. A long-acting injectable antibiotic called "cefovecin" (Convenia®) is often used since no oral manipulation is needed and one injection lasts two weeks.

During a particularly painful flare up sometimes a fentanyl patch is helpful for pain control. This is a small plastic patch that is generally applied to the back of a foot. It releases a continuous supply of pain relief for 5-7 days.

Other therapies to try might include the use of dilute interferon-alpha, an immune modulator that theoretically helps normalize immune reactions. This product is used commonly in the management of cats with Feline Immunodeficiency Virus or Feline Leukemia Virus infections as these cats become immune-suppressed. The product is a salty liquid that can be squirted in the mouth or mixed in food. Response to interferon is hit or miss but may be worth a try.

Bovine Lactoferrin is a natural compound that is similarly immunomodulating and antibacterial. It can be formulated by a compounding pharmacy into a palatable liquid. Bovine Lactoferrin is used to bathe the tissues of the mouth. Initial studies showed a large percentage of affected cats responded at least partially.

If these methods are ineffective, stronger immune-suppressive medications such as gold salts or chlorambucil have been recommended but this approach has fallen out of favor. If long term antibiotics, plaque management, bovine lactoferrin, and Interferon alpha do not control the condition then the next step would be referral to a veterinary dental specialist for full mouth extractions.

By the time the cat sees a veterinary dental specialist, the above medical treatments have been used and exhausted. The only thing left to do is extract the teeth that the cat is reacting to. In most cases this means every tooth in the mouth must go though sometimes the canine teeth (fangs) can be spared. The inflammed proliferative tissue is surgically removed. One might think a cat with no teeth would have difficulty eating but, in fact, once the pain clears up from the years of gum disease cats are much more comfortable eating than they have been in some time. They cannot chew their food but are happy to swallow it whole be it canned food or dry. There is an approximately 85% cure rate with full mouth extractions. Cats that test positive for calicivirus tend not to respond as well.


  • Plasma Cell Stomatitis is a painful, chronic condition.
  • Proper diagnostics including an oral biopsy are needed to confirm the diagnosis and get the correct treatment.
  • Medical management including regular dental care and medication represents the first level of treatment. If this fails, the cat will probably need to have all his/her teeth extracted by a specialist.
  • This can be a very frustrating disease to treat.

Page last updated: 4/3/2011