Overview of cats’ dental oral pathologies will be presented. Most oral problems cause pain and infection, therefore appropriate diagnosis should be followed by management of the diagnosed diseases. For cats the focus will be on inflammatory diseases.
Caudal stomatitis is a severe inflammatory reaction of the oral tissues of cats. It is a clinical diagnosis of inflammation and proliferation of the gingiva and oral mucosa. Specifically, it is inflammation associated with the caudal mouth (mucositis), which is the delineating factor between caudal stomatitis and periodontal disease.
Multiple etiologies may exist that, either singularly or combined, create the inflammation. Possible causative agents include an inflammatory response to plaque bacteria, viruses (FCV), Bartonella henselae infection, or altered immune status (FeLV or FIV).
Caudal stomatitis is a clinical syndrome and does not indicate a specific etiology or diagnosis. Diagnosis is made by visual inspection of the oral cavity. Diagnostic tests to further define the disease should minimally include dental radiographs, a minimum database (CBC, chemistry panel, T4, UA) to evaluate for underlying and/or concurrent systemic health problems, and evaluation of FeLV/FIV status. A biopsy should be taken and submitted for histopathology, especially if the inflammation is asymmetrical or otherwise atypical, or if radiographic findings are suspicious for neoplasia.
Controlling inflammation is the key to management of this disease process. Therefore, any tooth affected with inflammation from any cause should be extracted. All remaining teeth must receive strict homecare and routine professional cleanings to keep inflammation at bay. However, since the majority of patients have widespread inflammation, the most successful long-term treatment for cats with chronic gingivostomatitis is the complete extraction of all premolars and molars including the periodontal ligament as well as smoothing the alveolar bone. An additional step taken by many veterinary dentists is to perform careful alveoplasty to remove periodontal ligament remnants, which has anecdotally improved success rates.
Extraction of the canine and incisor teeth is indicated when the inflammation extends to include the gingiva surrounding them. Postoperative dental radiographs must be exposed to document complete extraction of all tooth roots.
In cases where owners are reluctant to have multiple extractions performed early in the course of treatment, medical management may be attempted to reduce bacterial load and inflammation. The majority of the products utilized are oral medications, which require daily to twice-daily administration. This is difficult to achieve in cats in general, and the oral pain and inflammation only serve to complicate matters. Finally, many of the products have significant side effects.
Systemic antibiotics may result in some improvement in the amount of oral inflammation. However, this is generally temporary at best, and most patients will relapse even during the course of antibiotic therapy. Rinsing with a 0.12% chlorhexidine gluconate solution may also be beneficial in some cases.
Corticosteroids are by far the most commonly used and effective drugs for immune modulation. However, long-term use of corticosteroids may have detrimental effects such as the induction of diabetes mellitus and opportunistic infections. Use the lowest effective dose and monitor biochemical values on a regular basis. Injectable treatment (methylprednisolone 10–20 mg SC) is usually recommended initially, due to the degree of oral pain. This typically results in clinical improvement within 24–48 hours, and lasts for 3–6 weeks.
Cyclosporine A has been purported as an immunosuppressive drug for cats with chronic gingivostomatitis. Some have promoted as an alternative to extractions in order to avoid the use of glucocorticoids. However, this author prefers to withhold its use to those cases where additional medical management is necessary post-extractions. There is scant information which supports its use other than one unpublished veterinary study, which showed efficacy in cases refractory to extractions. However, it may provide an alternative to long-term steroid therapy.
Feline interferon. There is currently significant interest in the use of this product for caudal stomatitis. It is reported to not only provide an antiviral effect, but to also provide an immunomodulatory effect and bring about a return to normal local immune response. The preferred method at this point is to inject 5 MU intralesional (often at the time of extractions) and then follow this up with the remainder of the vial (5 MU) diluted into 100 cc of sterile saline and administered per os by the owner at a dose of 1 ml once daily for 100 days.
Tooth Resorption (TR)
Completely subgingival TRs (those that have not progressed to the crown of the tooth) likely cause no discomfort for the patient. This presumption is based on the fact that similar lesions in humans are non-painful. Once lesions progress to the crown of the tooth, they are typically very painful; however, cats rarely show overt clinical signs. It is possible that the tissue filling the defect may provide some protection from sensitivity.
Most TRs are quite large before they become clinically evident. Therefore, it is very important to perform a thorough oral exam on all cats. Visualization of a resorptive defect near the gingival margin is almost diagnostic for a TR. The vast majority of feline patients afflicted with TRs will show no outward clinical signs. However, patients have been presented for oral pain, anorexia, ptyalism, lethargy, depression, dysphagia, and halitosis.
The lesions are first clinically evident on the crown at the gingival margin when the internal resorption reaches the enamel. The gingiva surrounding the teeth with type 1 lesions is usually affected with a significant inflammatory problem such as L/P stomatitis or periodontal disease. In cases of periodontal disease, it is very common to have calculus covering the lesion. This calculus must be removed to properly diagnose the lesion. The clinically visible defect typically indicates a much larger subgingival defect (tip of the iceberg). Hyperplastic inflamed gingiva also often conceals the defect.
Type 2 TRs are usually associated with only localized gingivitis on oral exam, in contrast to the more severe inflammation due to periodontal disease or gingivostomatitis seen with type 1 lesions. Type 2 TRs often begin just below the gingival surface near the cemento-enamel junction close to the gingival margin, or “neck” of the tooth. Visualization of a defect on the tooth surface or of gingival hyperplasia onto the crown surface is indicative of a TR. The lower third premolar is commonly the first tooth affected in these cases; however, canines can also be affected without other teeth being involved. Cats with a type 2 TR will generally have more than one lesion and are at increased risk for developing additional lesions.
Restoration of any TR carries a very poor prognosis because the odontoclasts remain present under the restoration, and therefore the resorptive process continues. In short order, usually around 6 months, the restoration will be lost and the pain and inflammation will recur. In addition, the visible lesion normally represents only a small part of the actual pathology (i.e., tip of the iceberg).
Treatment of choice for teeth with TRs is extraction. Recently, crown amputation has been suggested as an acceptable treatment option for advanced type 2 lesions. Crown amputation can only be performed on teeth with radiographically confirmed type 2 TRs which show no periapical or periodontal bone loss, with roots which are being completely resorbed. Crown amputation should not be done for teeth with type 1 TRs, radiographic or clinical evidence of endodontic or periodontal pathology, inflammation, or infection. It should also not be performed in patients that have any evidence of inflammation in the caudal tissues between the upper and lower molar teeth, or that are known to be positive for retrovirus. Those practitioners without dental radiology capability should not perform crown amputation. In these cases, the teeth should either be fully extracted or the patient referred to a facility with dental radiology.
Eosinophilic Granuloma Complex (EGC)
Eosinophilic granuloma complex is a group of conditions which share a common etiology, as well as some histopathological features. While these lesions have been reported in dogs (especially Siberian huskies, malamutes and cavaliers), they are much more common in cats. The discussion in this section will relate to cats, although the disease process is similar in either species. The true etiology of these conditions is unknown. Local accumulation of eosinophils (and their release of inflammatory agents) is thought to initiate the inflammation and necrosis seen in most of these lesions. The presence of eosinophils suggests that these lesions are secondary to an immune-mediated or hypersensitivity reaction.
The acute disease process is best treated with corticosteroids. However, corticosteroids should not be used for long-term disease control, due to the significant systemic side effects. The typical initial protocol is prednisone 2 mg/kg q 12 hours for 3–4 weeks. Other corticosteroid options include intralesional triamcinolone (3 mg weekly) or methylprednisone injections (20 mg q 2 weeks). Author prefers betamethasone (Diprophos) injections. Antibiotic therapy is required in some cases to induce remission or to treat secondary infection. In addition, there are cases that appear to respond to antibiotic therapy alone as has doxycycline at 10 mg/kg PO q24h.
Many cases remain idiopathic and require lifelong therapy. Options for long cyclosporine. Cyclosporine has recently been introduced as a veterinary labeled product for atopy and appears as effective as corticosteroids for atopic dermatitis in dogs and cats. Cats should be treated for 60 days with 25 mg/cat (4.9 to 12.5 mg/kg), given 2 h before a meal. It has also been proven to be an effective medication for long-term therapy of oral eosinophilic diseases. In addition, a lower incidence of severe side effects may be expected in comparison to steroids. This is especially valuable in cases requiring long-term therapy.
Surgical removal of these lesions has been performed with some success, including laser and cryosurgery. Finally, radiation treatment has been used effectively in some cases.
Periodontal disease is a very common problem in veterinary patients. It has numerous severe local and systemic ramifications; however, outward clinical signs occur only very late in the disease course. This means that it is significantly underdiagnosed, and even when recognized and treatment recommended, clients are reluctant to comply as they do not perceive the problem. Regardless, proper and prompt therapy of periodontal disease is beneficial for the health of the patient as well as financially for the practice.
Juvenile gingivitis occurs in young cats around the time of permanent teeth eruption and is associated with marginal and free gingiva inflammation circumferentially. This is inflammation of the gingiva during and just after tooth eruption and may be accompanied by persistent deciduous dentition. The gingival bleeding index is II or III so bleeding may occur on probing or spontaneously. Thick plaque deposition is present but gingival probing depth not necessarily exceeds 1 mm. This is self-limiting in most cases; however, home care (brushing or chlorhexidine rinses are recommended to decrease the inflammation. If the condition does not resolve in a short period of time, additional diagnostics and therapy are recommended as this could tend to switch into juvenile periodontitis.
Feline Orofacial Pain Syndrome (FOPS)
Feline orofacial pain syndrome (FOPS) is a pain disorder of cats with behavioural signs of oral discomfort and tongue mutilation. FOPS is suspected to be a neuropathic pain disorder and the predominance within the Burmese cat breed suggests an inherited disorder, possibly involving central and/or ganglion processing of sensory trigeminal information. The disease is characterised by an episodic, typically unilateral, discomfort with pain-free intervals. The discomfort is triggered, in many cases, by mouth movements. The disease is often recurrent and with time may become unremitting - 12% of cases in this series were euthanased as a consequence of the condition.