Can you make the dental diagnosis?

The vast majority of feline dental problems can be grouped into five categories: periodontal disease, feline odontoclastic resorptive lesions, fractured teeth, feline gingivitis/stomatitis syndrome and oral neoplasia.

In the previous article in this two-part series (June, p. 12S), periodontal disease was discussed. This month, we will consider fractured teeth, feline odontoclastic resorptive lesions, feline gingivitis/stomatitis syndrome and feline oral neoplasia in a case report perspective.

Figure 1: maxillary canine tooth.

The following four cases represent some of the most common feline dental problems. Read the case summaries and view the accompanying photographs to answer the quiz questions.

Case 1

George, a 6-year-old male domestic shorthair cat, was presented for oral evaluation. George had previously been diagnosed with a dermatologic disorder and had been prescribed therapeutic baths. During one such bath, a week ago, George did a flip in the bathtub and landed on his tooth. He refused to eat for two days following the injury, and a small amount of blood was noted in the saliva directly after the injury took place.

Figure 1 shows George's left maxillary canine tooth.

• 1. What is you diagnosis?

• 2. What treatment options can you recommend?

• 3. Is simply monitoring this problem with no treatment a viable option?

Case 2

Sasha, an 8-year-old female domestic shorthair cat, was presented for her annual examination and rabies vaccine. Her owner did not report any problems, but Sasha now seems to prefer canned food to her kibble.

Figure 2a: Note the mandibular third premolar.

Figure 2a shows Sasha's oral lesion

Figure 2b shows an intraoral radiograph of that lesion.

• 1. What is the name of this lesion?

• 2. Could the owners have prevented it by better oral hygiene?

Figure 2b:Intraoral radiograph of the left mandibular premolars and molar.

• 3. What are the treatment options for this lesion?

Case 3

Sally, a 4-year-old spayed female Siamese cat, was presented with the clinical signs of severe halitosis, ptyalism, partial anorexia and general malaise. Aside from the oral examination, the remainder of the physical examination was normal except for a mandibular lymphadenopathy. Results of serologic test for FeLV, FIV and Bartonella were negative.

Figure 3 shows Sally's oral lesions.

Figure 3:Note the distribution of the inflammation.

• 1. What is the presumptive diagnosis?

• 2. What test is needed to confirm this diagnosis?

• 3. What are the treatment options for the presumptive diagnosis?

Case 4

Ralph is a 14-year-old male domestic shorthair who presented with a history of halitosis, pawing at the mouth and anorexia.

Figure 4a shows Ralph's oral lesion.

Figure 4a:The left mandibular canine tooth is loose.

Figure 4b shows an intraoral radiograph of this lesion.

• 1. What procedures are indicated to confirm a diagnosis?

• 2. What is the most common oral neoplasia in cats?

Case 1 answers:

• 1. Fractured left maxillary canine tooth with pulp exposure.

• 2.. Extraction or possibly root canal therapy.

• 3. No.

Figure 4b: Intraoral radiograph of the left mandibular canine tooth.

Tooth fracture occurs most commonly in cats following trauma. When a tooth has been broken, the pulp chamber is often exposed to the oral environment. The pulp exposure can be visualized on oral examination as a pink (vital pulp) or black (necrosed pulp) spot at the site of exposure.

Any time a pulp cavity is exposed, it must be treated. Exposed pulp is painful to the animal and can lead to periapical osseous infection. There are two treatment options whenever an exposed pulp is encountered. The first is to extract the tooth; extraction fulfills the treatment goals of preventing pain and infection, as long as no broken roots are left behind. A second option is to save the tooth by performing endodontic therapy (root canal) if an intraoral radiograph shows the tooth to be treatable. Teeth with evidence of resorptive lesions are not candidates for endodontic therapy and should be extracted.

Case 2 answers

• 1. Feline odontoclastic resorptive lesion.

• 2. No.

• 3. Extraction.

Feline odontoclastic resorptive lesions (also known as neck lesions, cervical line erosions and cat cavities) are the most common dental problem in cats. Studies worldwide have shown incidence rates in cats presented for dental problems of up to 75 percent. Feline odontoclastic resorptive lesions (FORL) are painful. Clinical signs associated with FORL include anorexia, drooling, refusal to eat the hard portions of the diet, and overall malaise. The most common sign of pain in cats, however, is no sign at all.

On oral examination, these lesions are often associated with a localized, cherry-red, sometimes-hyperplastic area of gingivitis. The most commonly effected teeth are the mandibular third premolars, the maxillary third and fourth premolars, and the canine teeth; however, all 30 teeth in the cat's mouth are at risk. FORL lesions can be demonstrated on oral examination by gently brushing the suspected lesion with a thin wisp from a broken wooden "Q-tip." Gentle stimulation of these lesions invokes a strong jaw-chattering response.

Restoration of FORL is controversial. The controversy lies in the fact that the majority of restorations fail. With these poor results in mind, and the etiology of this disease unknown, it has been the opinion of the majority of the veterinary dental community that all teeth affected with FORL be extracted. A crown amputation procedure has been described for "extraction" of teeth exhibiting FORL.

In this procedure, the crown of the tooth is removed while intentionally leaving the roots behind. Cats with associated periodontal disease or gingivitis/stomatitis should never be considered candidates for crown amputation. Dental radiography is essential for accurate diagnosis and treatment planning.

Case 3 answers

• 1. Feline gingivitis/stomatitis syndrome.

• 2. Biopsy of the lesion.

• 3. Medical or surgical management.

The most successful drug appears to be methylprednisolone acetate. This drug has its potential side effects and negative consequences, including the inevitable development of diabetes. Long-term medical treatment is not recommended.

Surgical treatment, involving extraction of all teeth caudal to the canines, has been shown to be 85 percent effective in curing this disease.

Probably the most frustrating oral disease we see in our clinical practice is feline gingivitis/stomatitis syndrome (FGS). Cats will present with clinical signs of partial to complete anorexia, drooling, halitosis and oral pain. Physical exam will show various signs of gingivitis (inflammation of the gingiva), stomatitis (inflammation extending to the oral mucosa), palatitis, faucitis (inflammation of the caudal fauca), glossal ulceration and pharyngitis. There is often an associated submandibular lymphadenopathy. When a cat presents with clinical signs compatible with this syndrome, a complete diagnostic workup is necessary.

To start, a complete physical exam, CBC/chemistry, feline serology and other ancillary tests as indicated should be performed. The results of the blood tests are usually unremarkable, except for a hyperproteinemia resulting from a hypergammaglobulinemia. The feline retrovirus infections are certainly associated with oral inflammation, but most cats with FGS are retrovirus negative.

Next, a dental prophylaxis should be performed. All teeth exhibiting feline odontoclastic resorptive lesions and all teeth with end-stage periodontal disease should be extracted. Also, any root tips or fragments need to be removed. Never leave root tips behind in these cases. Dental radiographs are essential when evaluating for retained roots. A biopsy should be performed, including samples from the gingiva and effected areas in the pharynx.

The results of the biopsy often show "lymphocytic-plasmacytic stomatitis." This is not a diagnosis. This is the typical histological picture whenever cats have chronic inflammation. The histopathological results that we may see to alter our treatment include eosinophilic granuloma, autoimmune diseases or neoplasia.

Following dental prophylaxis, the owners need to be counseled to provide daily home care. Most cases of feline gingivitis are thought to result from an over-exaggerated immune response to plaque bacteria. In some cases, simply keeping the oral environment clean will keep this condition in check.

When the biopsy results show lymphocytic/plasmacytic inflammation and home care is not working, treatment options include medical or surgical management. Surgical treatment, involving extraction of all teeth caudal to the canines, has been shown to be 85 percent effective in curing this disease. This is a labor-intensive procedure, and will not be successful if any root fragments are left behind.

In some cases, areas of inflamed or infected bone surrounding the alveolus also need to be removed. It is difficult, if not impossible, to perform this procedure without dental X-rays and high-speed drills.

Case 4 answers

• 1. Complete physical examination, appropriate blood tests, thoracic radiographs (three views), regional lymph node evaluation, intraoral radiographic examination and biopsy of the lesion. CT scan may also be of benefit.

• 2. Squamous cell carcinoma.

Unfortunately, the vast majority of neoplasms found in mouths of cats are malignant and carry a poor prognosis. More than 20 different types of cancer have been reported to occur in the oral cavity of felines, although only a few are observed commonly.

Among the more common feline oral neoplasms are squamous cell carcinoma (SCC), fibrosarcoma, lymphoma and malignant melanoma. Squamous cell carcinoma is by far the most common, accounting for about 70 percent of feline oral neoplasms. It is of extreme importance to identify the tumor type and commence treatment early in the course of disease if a favorable treatment outcome is to be achieved.

In the majority of cases, however, a clinical cure is not possible.

Any swelling (soft tissue or bony) or abnormal appearance of tissue in the oral cavity must be considered suspicious for neoplasia. A common, but very subtle, presentation of oral neoplasia is when a tooth can be extracted too easily. The results of the biopsy should be discussed with a veterinary oncologist to offer up-to-date treatment options and prognosis.