Feline Oral Diseases

8/3/2019 Feline Oral Diseases

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FELINE ORAL DISEASES: AN UPDATE

Dr. A. Caiafa BVSc BDSc MACVScUniversity of MelbourneVeterinary Clinic and HospitalPrinces Highway, Werribee, 3030Email [email protected]

Introduction

Feline oral diseases can often be a source of frustration and anxiety for thepracticing veterinarian. Veterinarians are all too aware of the difficulties with thediagnosis and management of oral diseases in cats.This lecture will look at the common (and the not so common) ailments that afflict thefeline mouth.

More commonly seen diseases

Periodontal disease

Odontoclastic resorptive lesions (ORL)

Trauma- MCA, high rise syndrome, cat/dog fights

Less commonly seen

Feline gingivitis/stomatitis syndrome (FGS)

Oral neoplasia

Nasopharyngeal polyps

Eosinophilic granuloma complex

Calici virus infection- acute and chronic

Others- FB, uraemia, diabetes mellitus, malocclusions

Periodontal disease (PD)

PD is probably the most common chronic disease seen in the cat today. Thisdisease is bacterial in origin, but contributing to the disease is the host responsewhich through the release of inflammatory mediators can exacerbate the periodontalattachment loss. Compounding the complexity of this disease is the cat with acompromised immune system (i.e. FIV positive cat) which when combined with thepresence of plaque bacteria leads to a more acute and severe manifestation of thedisease.

The primary cause of PD is gram negative anaerobic bacteria. PD is oftenasymptomatic in its early stages, with the cat only displaying such symptoms aspain, dysphagia and halitosis towards the later stages of the disease. PD can also beseen in combination with another common oral ailment namely odontoclasticresorptive lesions (ORL).

Management of PD in cats can be complicated by the difficulty in performinghomecare. Often owners resort to diet as a means of controlling or preventing PD incats.

Two common errors made by veterinarians in the management of PD are poor clienteducation re the chronic nature of the disease and the lack of review and continuingassessment of cats with PD. Clients need to know that the disease is chronic andthat their cat needs to be reviewed on a regular basis to assess disease stability or


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progression. The clients ability or inability to perform adequate homecare shouldalso be considered in the management of PD.

Odontoclastic resorptive lesions (ORL)

ORL is a very common disease of cats. At the present time, the aetiology of ORL isnot known.Like PD, ORL may be asymptomatic, although dysphagia, ptyalism, face rubbing,jaw chattering, poor appetite and weight loss may be some of the symptoms seenwith this disease.Oral examination may show abundant plaque and calculus covering the posteriorteeth, while hyperplastic gingiva may sometimes be seen extending onto the erodedtooth surface.ORL can be confused with feline gingivitis/stomatitis syndrome, especially whenthere are retained roots in the mouth.

Prevalence of ORL

Prevalence rates of 28-57% have been reported in the literature and older cats aremore likely to be affected, with the number of lesions increasing with age.Asian short-hair cats appear to be more susceptible, although any breed/domesticcat can be affected. Some studies show male cats to be more prone to ORL thanfemales, and the disease often exists in conjunction with PD.

Clinical appearance

Posterior teeth are more commonly affected than anterior teeth, and diagnosis isoften difficult when the affected teeth are covered with plaque, calculus or inflamed

gingiva.In one study, the two most commonly affected teeth were the maxillary andmandibular fourth premolars. Lesions are more common on the buccal surface of thetooth, and often start in the cervical area, extending both apically and coronally.

Aetiology of ORL

As yet, there is no known cause, but many theories and suggestions have been putforward to explain this most perplexing disease.Gorrel (2003) concludes that ORL may be two separate disease processes, onepredominantly affecting the cervical or neck area of the tooth, while the other

process affects the root of the tooth and may not show any tooth loss above thealveolar bone margin.Some veterinarians felt that dietary or endogenous acids are the trigger in initiatingthe lesion. Others put forward the idea of occlusal stresses (so called abfractionlesions) being the cause and still others incriminated viruses as the initiator.

Diagnosis

Diagnosis is usually based on clinical examination with a dental explorer and the useof intra-oralradiography especially for subgingival lesions.

Treatment of ORL

Early lesions involving enamel- topical fluoride? and monitoring.


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Lesions involving dentine+/- pulp: extraction is the current acceptedtreatment- can be very difficult extraction due to partial/complete rootankylosis.

Most ORL extractions require a surgical technique.

Restoring lost tooth structure? Today, an unacceptable method of treatment.

Other treatment options

Crown amputation technique described by Dupont. In the original study, DuPonttreated over a hundred teeth with crown amputation. Radiographs showed continueduneventful replacement resorption of the root structure with gingival healing.

Trauma

The most common oral injury in cats is mandibular symphyseal separation. This isusually due to MCA or falls. Simple circumferential wiring is the most effective way ofstabilising these separations.Mandibular/maxillary fractures in the cat can be more difficult to manage than in the

dog, due to the smaller head size, often the comminuted nature of the fracture andthe difficulty in applying tape muzzles, external or internal fixation.Inter-arcade or interdental fixation or both have offered a valuable alternative totraditional methods of fracture repair.Temporo-mandibular joint injuries do occur in cats. Ventro-rostral luxation is oftentreated by closing the jaws together while a wood or plastic rod separates the upperand lower carnassial teeth on the side involved, then pushing the involved mandiblecaudally. Fractures involving the temporo-mandibular joint area that have resulted inankylosis or pain in the joint can be treated by mandibular condylectomy.

Traumatic tooth fracture is not uncommon in cats.

The canine teeth are most commonly affected and often the crown fracture iscomplicated and involving the pulp. Treatment of a complicated crown fractureusually requires either extraction, complete or partial pulpectomy.

Feline gingivitis/stomatitis syndrome (FGS)

Gingivitis/stomatitis in the cat is the cause of a lot of heartache for both thepractitioner and the client. Often cats present in severe pain, with ptyalism,dysphagia and marked weight loss.Histologically, it is characterised by an infiltration of plasma cells and lymphocytespossibly in response to polyclonal B-cell activators in oral bacteria. Other co-factorssuch as viruses and proteins have also been incriminated.Pure breed cats (Siamese, Persians) may have more severe disease than othercats.

Aetiology

Aetiology unknown, multifactorial disease?

Viral ?- Chronic Calici viral infection, Corona virus

May be due to chronic antigenic stimulation and an inability to moderate

the host response: polyclonal B-cell activation Can see hyper/hypo response of immune system to plaque bacteria, other

antigens such as food additives (cinnaminase, Benzoin), viruses.

Cats with FGS seem to be very plaque sensitive suggesting thatperiodontal disease plays a large part in the disease.


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Diagnosis of FGS

A complete oral examination is normally performed under general anaesthesia dueto the painful nature of the disease. A hematological workup including viral assays isnecessary to rule out FIV, FeLV and other possible causes.Biopsies may be required especially where lesions are asymmetrical and viral cultureof lesions may be of benefit to rule out calicivirus infection. Bacterial culture andsensitivity testing may also be required if there is a poor response to empiricallychosen antibiotics.

Management of FGS

No one treatment is successful. Owner education: prepare the owner for along battle.

Professional scaling/cleaning with extraction of teeth with poor prognosisshould be your starting point. However, often this is unsuccessful longterm.

Any root fragments need to be removed. Never leave fractured root tipsbehind in these cases when extraction is necessary. Intra-oral dentalradiographs are essential when evaluating for retained roots.

Often lack of permanent response to meticulous oral hygiene, professionalscaling, antibiotics, anti-inflammatories and immunosuppressant drugs(better to use liquid or parenteral administration if considering drugtherapy).

Other drugs including: Aurothioglucose- gold compounds, oral cyclosporin10mg/kg SID

Hypoallergenic diets where food allergy suspected.

Refractory cases often require caudal (premolar/molar) extractions; if notthe entire dentition- currently this treatment shows the highest successrates in resolving the inflammation.

However, in a study of 30 cats, 7% showed no improvement after multipleextractions (Hennet,1994)

Oral neoplasia

The most common oral neoplasia in the cat is Squamous cell Carcinoma (SCC).A common site for feline SCC in the mouth is the ventral tongue. The cancer is oftendetected too late for local control and cats do not respond well to partial

glossectomy. Early detection may offer a better prognosis.Feline oral fibrosarcoma is the second most common oral tumour in the cat. It also isvery difficult to manage, but early diagnosis and surgery offer the best chance forcure. Intralesional anti-cancer drugs have also been tried with varying success.

Nasopharyngeal polyps

This inflammatory disease tends to occur in young cats. Clinical signs includesneezing, swallowing and breathing difficulties. Firm fleshy masses may be palpatedin the caudal pharynx or above the soft palate. Occasionally masses may bevisualized in the external ear canal.

Most polyps originate in the tympanic bullae or Eustachian tube and grow towardsthe pharynx.Treatment through the oral cavity involves traction and ligation to try to remove asmuch of the stalk as possible, but recurrence is common. If a polyp occurs in thebulla, a bulla osteotomy may be required to remove the polyp.


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Eosinophilic granuloma complex (EGC)

EGC classically has three forms, namely eosinophilic ulcer (rodent ulcer),eosinophilic plaque and linear granuloma (collagenolytic granuloma).Rodent ulcers occur on the upper lip and hard palate. Females may be morepredisposed. The lesions are often associated with excessive licking.Eosinophilic plaques are raised ulcerated, erythematous and hairless lesionsoccurring on the skin of the lower abdomen, groin, neck and between the toes.These lesions may be very pruritic.Linear granuloma occurs mainly in young animals and can present in the oral cavityand pharynx as raised, linear yellowish plaques especially on the tongue.

Possible aetiologies for eosinophilic granuloma complex include:

Allergies: Atopy, flea bite dermatitis, mosquito bites, food allergy

Chemical: contact irritants, insect parts- FB reaction

Genetic: colony of cats specifically bred at Davis University

Treatment involves identifying and removing the underlying cause. This may involvefastidious flea control of all in-contact animals, a strict elimination diet and avoidanceof environmental allergens (difficult).Drug therapy often involves high doses of corticosteroids especially injectablemethylprednisolone acetate (4mg/Kg every 3 weeks for 3 doses) or oralprednisolone (1-3 mg/kg SID until resolution then alternate days).Initially antibiotics may be required to treat the secondary skin infection associatedwith the pruritus. Doxycycline (10mg/kg SID) is a good antibiotic choice because ofits anti-collagenase activity as well as its antimicrobial action.Other immunosuppressive drugs (chlorambucil- 0.1-0.2 mg/kg on alternate days)

may be used in combination with corticosteroids in refractory cases.

Other oral diseases

Foreign bodies- needles under tongue

Renal disease and oral uraemic ulcers

Diabetes mellitus- dehydration, neutrophil dysfunction leading toperiodontitis.

Malocclusion- Persian cats with rostrally tipped maxillary canines. Ingeneral malocclusions are rare in cats.

References

DuPont G. Crown amputation with intentional root retention for advanced felineresorptive lesions: a clinical study. J Vet Dent 1995;12: 9-13Grippo JO Abfractions; a new classification of hard tissue lesions in teeth. J EstheticDent 1991; 3:14-19Hennet P, Results of periodontal and extraction treatment in cats with gingivo-stomatitis. Proceedings of the World veterinary dental Congress, Philadelphia, 1994,49.Ingham KE, Gorrel C. Prevalence of odontoclastic resorptive lesions in a population

of clinically healthy cats. J Small Animal Practice 2001 42: 439-443Reubel GH et al. Acute and chronic faucitis of domestic cats. A feline calicivirus-induced disease. Vet Clinics North America: Small Animal practice 1992; Vol22,6;1347-1359


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Scarlett JM et al. Risk factors for odontoclastic resorptive lesions in cats. J Am AnimHosp Assoc 1999; 35:188-192Wiggs RB, Lobprise HB. Veterinary Dentistry: principles and practice. Philadelphia;lippincott-Raven, 1997: 487-90Zetner K, Steurer I. The influence of dry food on the development of feline necklesions J Vet Dent 1992:9: 4-6

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Feline Oral Diseases