Chronic ulcerative paradental stomatitis: When 'kissing' isn't a good thing


This veterinary dental condition, also called kissing lesions, can be extremely painful in affected pets and requires immediate and dedicated care.

As soon as I walked into the exam room, I knew the patient on the table was in trouble. The odor emanating from the dog's mouth was overwhelming. When queried, the owners said they had barely noticed and had only noted that their dog had stopped eating. Putrid saliva flowed onto the exam table (Figure 1A).

Figure 1A: A patient with thick ropey foamy saliva secondary to contact mucositis and ulceration. (Photos courtesy of Dr. Jan Bellows.)

The 14-year-old Maltese cross had an advanced case of contact mucositis with ulceration. The dog's owners had been dealing with it for years. Multiple professional teeth cleaning visits with the dog's primary veterinarian, antibiotics, corticosteroids, a few extractions and even immune modulators met with little success. Lately, the dog had been in so much pain that tooth brushing was out of the question.


What is CUPS?

Chronic ulcerative paradental stomatitis (CUPS), also called contact mucositis, contact mucositis with ulceration and kissing lesions, affects the paradental mucosal tissues that lie next to the teeth. The oral mucosa, palatal mucosa, lining of the buccal pouch and epithelial lining of the tongue are most commonly affected (Figures 1B-1D). 

Figure 1B: "Kissing" lesions evident on alveolar mucosa apical to the adjacent teeth in the dog in Figure 1A.

Figure 1C: An inflamed right buccal vestibule caused by plaque on the caudal cheek teeth.

Figure 1D: Epithelial damage of the tongue and unilateral sublingual pyogenic granuloma caused by trauma from the caudal mandibular cheek teeth.


The lesions may present as solitary or multiple discretely circumscribed or diffuse areas of inflammation with or without ulceration (Figures 2A, 2B and 3).

Figures 2A and 2B: Discrete alveolar mucosa “kissing” lesions adjacent to the right and left maxillary canines and incisors with minimal periodontal inflammation, plaque or tartar.

Figure 3: A diffuse ulcerated alveolar mucosa lesion with ulceration secondary to contact with the right maxillary canine.


The lesions may also present with fresh fibrinous pseudomembranes (Figure 4), pustular pseudomembranes (Figure 5) or chronic pseudomembranes with evidence of hemorrhage and necrosis (Figure 6).

Figure 4: A fresh pseudomembrane formed over a contact ulcer.

Figure 5: Multiple large contact ulcers in the labial mucosa overlying the right maxillary canine, incisors and premolar.

Figure 6: A chronic necrotic ulcer with hemorrhage overlying the caudal cheek teeth covered with plaque and tartar.


In cases in which the tongue's lateral surfaces are severely eroded, the patient is often in so much discomfort that it stops eating  (Figure 7).

Figure 7: Erosion of the lateral tongue epithelium with normal-appearing mandibular premolar teeth.

Occasionally the paradental infection is so marked that the necrotic buccal mucosal damage extends through the skin (Figures 8A-8C).

Figure 8A: Contact ulceration from the right maxillary second molar causing destruction of all tissues.

Figure 8B: Destruction visible from the facial surface.

Figure 8C: A large contact ulcer on the contralateral side.


Contact mucositis with ulceration differs from periodontal disease that affects the socket holding the tooth-the cementum, periodontal ligament, alveolar bone and gingiva. Some patients have both contact mucositis and periodontal disease (Figure 9).

Figure 9: A chronic ulcer and pseudomembrane in the buccal mucosa and advanced periodontal disease affecting the left maxillary fourth premolar.

The specific etiology is unknown. Maltese, Cavalier King Charles spaniels, Labrador retrievers and greyhounds are overrepresented. Affected animals may have a hyperimmune response to the bacteria and proteins in plaque. Other syndromes that may mimic contact ulcerative mucositis include autoimmune diseases such as mucous membrane pemphigoid, bullous pemphigoid, pemphigus vulgaris, epidermolysis bullosa and epitheliotropic T-cell lymphoma. Additionally drug reactions (early toxic epidermal necrosis) and foreign bodies appear similar. Keep in mind that in cases of pemphigus, other mucous membranes including the inner surfaces of the eyelids and the rectum can also be affected.

Unfortunately most affected patients are in so much pain they will not allow an oral examination. As part of patient assessment, laboratory tests including organ function profile, thyroid function, urinalysis and lesion biopsy should be performed. Expect elevated protein concentrations due to the chronicity of disease. In patients in which elevated alkaline phosphatase levels are reported, tests to rule out Cushing's disease should also be performed.


The treatment of patients with CUPS lesions involves medical intervention, surgical intervention or a combination of the two.

Medical. Affected patients are extremely sensitive to plaque. Even a small amount can initiate the ulcerative inflammatory reaction. Initial care involves dental scaling-both above and below the gum line-irrigation and polishing followed by diagnostic probing and intraoral radiography. Extract teeth with grades 3 and 4 periodontal disease. A dental sealant is recommended to help decrease plaque accumulation.

Antibiotics approved for dental infections are indicated to help treat severe presentations. Pentoxifylline (patient < 7 kg: 100 mg t.i.d.; 7 to 16 kg: 200 mg t.i.d.; > 16 kg: 400 mg t.i.d.) can be prescribed to decrease inflammation. Niacinamide with equal dosages of tetracycline (patient < 20 kg: 250 mg t.i.d.; > 20 kg: 500 mg t.i.d.) may also be helpful. Pain relief medication is also indicated. Pulsed antibiotic therapy (antimicrobials administered the first five days of each month) is not recommended. 

The use of corticosteroids to control CUPS is controversial. Home care, including brushing the pet's teeth twice daily, applying a gel or an oral rinse containing zinc and applying plaque prevention gel (OraVet Plaque Prevention Gel-Merial), helps with plaque control and ulcer treatment.


Surgical. Photovaporization with a carbon dioxide laser helps in the treatment of contact mucositis and mucositis with ulcerative lesions when combined with strict plaque control. The laser should be set between 3 and 6 watts in continuous mode (Figures 10A-10C).

Figure 10A: Multiple contact mucositis kissing lesions affecting the left maxillary alveolar mucosa in an 11-year-old Labrador.

Figure 10B: Ulcer vaporization of the lesions of the patient in Figure 10A using a carbon dioxide laser.

Figure 10C: Resolution of lesions after laser treatment and strict plaque control.


In advanced cases in which the owner cannot provide twice-daily plaque control or if such care does not meet with clinical success, removal of the teeth adjacent to the ulcerated areas (Figures 11A an 11B)-and in some cases all the teeth, as in the case of the dog discussed at the beginning of this article (Figure 12)-results in rapid elimination of all infection and pain. This may seem over the top, but giving your client a “new dog” that smells great, eats well and can truly enjoy life is worth it.

Figure 11A: Right causal buccal pouch inflammation secondary to contact mucositis.

Figure 11B: Resolution of inflammation after selective extraction of the caudal cheek teeth.

Figure 12: Resolution of the inflammation in the 14-year-old dog from Figures 1A-1D one week after full-mouth extraction.

Dr. Jan Bellows owns All Pets Dental in Weston, Florida. He is a diplomate of the American Veterinary Dental College and the American Board of Veterinary Practitioners. He can be reached at (954) 349-5800; email:

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