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 25-28 September, 2018 | Singapore
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.
Type 1
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
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 type2 lesions. Crown amputation can only be performed on teeth with radiographically confirmed type 2 TRs
which show no peri-apical 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) 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 and 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 triamcinalone (3 mg weekly) or methyl prednisone injections (20 mg q 2 weeks). Author prefers bethamethasone (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 longterm 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

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