Dental Corner: Diagnosing and treating chronic ulcerative paradental stomatitis

Dental Corner: Diagnosing and treating chronic ulcerative paradental stomatitis

Dec 01, 2004

Figure 1 : The classic presentation of CUPS: A Maltese that refuses to eat and whose breath is affecting every room in a three-story house.
Chronic ulcerative paradental stomatitis (CUPS) is a painful condition in dogs that is also known as ulcerative stomatitis, idiopathic stomatitis, and lymphocytic-plasmacytic stomatitis. The hallmark lesion is a paradental, or so-called kissing, ulcer.1 Patients with CUPS are usually inappetent or anorectic, and the chief complaint from owners is usually fetid halitosis and drooling. CUPS can affect any dog, but Maltese are overrepresented, and a familial predilection has been shown (Figure 1). Cavalier King Charles spaniels also seem to be genetically predisposed.2 While dogs of any age can be affected, I have rarely seen CUPS in patients under 1 year old.


CUPS lesions are characterized histopathologically by a predominance of lymphocytes and plasmacytes, indicating that the disease is inflammatory rather than infectious. The presumed antigen stimulating the inflammation is bacterial plaque,3 or in terms that pet owners can understand, the dogs become allergic to the bacteria that live on their teeth. Some veterinary dentists refer to this condition as plaque intolerance or plaque hypersensitivity.

As the inflammatory condition continues, gingivitis and advanced periodontitis (deep pocket formation, gingival recession, periodontal bone loss, furcation exposure) can occur concurrently. The change from predominantly gram-positive to predominantly gram-negative bacterial flora that occurs with periodontitis seems to fuel the inflammation of CUPS, suggesting to me that antigens from the gram-negative bacteria may trigger an even stronger inflammatory response in affected dogs.

The severe pain dogs experience from CUPS lesions makes it difficult for owners to provide adequate dental home care. This lack of home care and the patient's unwillingness to chew allow more plaque to accumulate, and the vicious cycle continues.

Clinical signs

Figure 2 : A paradental, or kissing, ulcer (black arrow) on the oral mucosa apical to the right maxillary canine tooth. Note how this tissue will contact the tooth surface when the mouth is closed.
Affected dogs exhibit various clinical signs including halitosis (sometimes severe), inappetence or anorexia, ptyalism, and oral pain (pawing at mouth, chattering jaw movements). Other signs may include abnormal chewing movements, eating difficulties, difficult prehension, and oral hemorrhage. Affected dogs often will not chew on their toys and will refuse the hard portions of their diets.

Figure 3 : Gingivitis, stomatitis, cheilitis, and inflammation along the tongue's lateral border. To diagnose CUPS, oral biopsy samples of affected areas need to be evaluated.
On oral examination, gingivitis, stomatitis, and, sometimes, advanced periodontitis are observed. The classic distribution of the stomatitis is paradental (Figure 2). The lesions on the oral mucosa correspond with areas that touch the teeth's surfaces. The lesions are red, sometimes slightly raised, and often ulcerated. In addition to the buccal mucosa, the lateral mucosa of the tongue is often inflamed and ulcerated where it touches the lingual mandibular teeth's surfaces (Figure 3). The most severe lesions are often found associated with areas of gingival recession. Concurrent sublingual granuloma, or gum chewers lesions, may exacerbate the problem on the lingual mandibular mucosa. Sometimes, dogs with CUPS will have a concurrent lip fold dermatitis (intertrigo) adding to the oral discomfort as well as an overall foul odor. The connection between these two conditions is most likely that excessive drooling from the CUPS contributes or exacerbates the lip fold dermatitis. Another finding consistent with CUPS is mandibular lymphadenopathy.