Feline Chronic Gingivostomatitis (FCGS)

Feline Chronic Gingivostomatitis (FCGS) is a relatively common and poorly understood disease. It presents as a range of symptoms ranging from severe inflammation and ulceration of most of the mouth and oral cavity to inflammation to certain areas of the mouth.

The term Gingivitis refers to inflammation to the gums closely associated to the teeth, whereas stomatitis refers to inflammation in other areas of the mouth, such as the alveolar, labial and buccal mucosa, and mucosa of the back of the throat.

Cause

The cause of the disease is still poorly understood, and likely is a multifactorial process and complex reaction involving of a number of factors.

Infectious agents that may be involved include FIV, FeLV, Herpes virus, Calicivirus and bacterial infections such as P. gingivalis, Bartonella or Tanerella forcythia.
Adverse reaction to food antigens (Food allergy) may play a role
Most likely there is an immune mediated problem, where the body is unable to moderate the immune response to common stimulants encountered in the mouth. This especially includes an excessive inflammatory response to plaque, and in cases of FIV there may be an inadequate local immune response. There are similarities between FCGS and conditions such as Feline Inflammatory Bowel disease and Crohn’s disease in man.
Some genetic predisposition may exist, with some breeds developing more severe disease such as Siamese, Persians, Abyssinians and Somalis, however any breed can be affected. FCGS is commonly seen in young to middle aged cats, with a mean age of 7 years.

Symptoms

Cats may have trouble eating, pain on opening the mouth, drooling saliva, difficulty picking up or chewing food or toys, bad breath and weight loss. Affected cats may become less active, reluctant to groom themselves, and become aggressive towards their owners. It is a very painful disease.

On examination there may be ulceration and redness of the mucosa of the gingiva around the teeth, but also extending to the other areas of the mouth such as inner lips, sides of the tongue, roof of mouth and the back of the throat area. The inflammation present near the back of the throat next to the palatoglossal folds is called caudal stomatitis, previously termed faucitis or caudal mucositis. In severe cases proliferative tissue may be present in the back of the throat area with spontaneous bleeding. There may be variable concurrent periodontal disease with tartar and resorptive lesions. Many affected cats also have a degree of oesophagitis and sometimes gastritis.

Diagnosis

Extensive testing is required to fully diagnose FCGS and to identify concurrent and contributing factors. To investigate your cat’s gingivitis and stomatitis, the following investigation and tests may be recommended:

A thorough examination under general anaesthesia of the mouth, gingiva, oropharyngeal mucosa and teeth, including complete dental radiographs. This helps the veterinarian to identify and address common contributing problems such as periodontitis, retained tooth roots or bony sequestra. During the examination oral tumours or inflammatory lesions such as Eosinophilic granuloma may be identified. The severity and distribution of inflammation can be graded and documented which helps assessing success rates of treatments in the future. At the time of this examination under general anaesthesia a thorough dental cleaning procedure usually will be recommended. This may include the extraction of any diseased teeth, and any retained tooth roots, to help reduce the ongoing source of local inflammation.
A biopsy of the mucosa or of any lesions may be taken at the time to help confirm this disease and rule out other inflammatory conditions or oral tumours, especially if there is asymmetrical disease.
Blood tests may be undertaken including a Complete Blood Count, Biochemistry profile, Urinalysis, Viral testing for Feline Leukaemia and Feline Immunodeficiency Virus, and possible testing for Calicivirus. This helps to assess your cat’s general health, and identifies concurrent conditions that may affect the immune system and contribute to oral inflammation.

Management

Management of FCGS can be frustrating and difficult. There is not one single treatment that proves successful, often multiple treatment approaches have to be undertaken. The basis of most treatment approaches is to reduce the number of bacteria in the mouth, and to modulate the immune response with medications.

Cats with caudal stomatitis have a worse prognosis and unfortunately some cases may even be refractory to treatment.

It is important to remember that the primary goal in management of FCGS is for your cat to be as pain free as possible. Many cats still may have ongoing inflammation, however are able to eat and appear relatively comfortable.

Meticulous regular professional dental treatment and cleaning with aggressive home care: Your cat may respond to frequent professional dental cleaning and very dedicated home care. This entails frequent professional scaling and polishing of teeth under general anaesthetic, often 2-4 times per year. In addition, dedicated home care including daily cleaning of teeth, oral antiseptic treatment and other home care products is absolutely imperative to ongoing success. Frequent monitoring will be required to assess if the home care maintenance is successful and when the next dental cleaning procedure will be required. This often means 3 – 6 monthly check ups with your veterinarian to grade the inflammation in your cat’s mouth and check for any plaque or tartar accumulation.
Antibiotic and/or anti-inflammatory treatment: Antibiotics and anti-inflammatory medication may be used in the short term post dental cleaning and extraction procedure. However antibiotics, steroidal or nonsteroidal medications are NOT effective in the long term on their own. Antimicrobial resistance can occur, side effects occur with long term anti-inflammatory use and response to treatments becomes less effective with time. Most importantly, if the inflammation in your cat’s mouth becomes chronic, this condition becomes increasingly difficult to manage in the long term, with poorer response to eventual surgical treatment.
Immune suppressive/immune modulatory medication: Medications such as Corticosteroids, Interferon and Cyclosporine are commonly used. These medications have their own side effects, success rates and associated costs. They are commonly used as adjunct treatment after dental extractions, and in refractory cases.
Full or selective mouth extractions: Currently this is the best recommended long term treatment option in Feline Chronic Gingivostomatitis. Success rates are significantly improved if surgery is performed early in the disease, with slowed and poorer response encountered in chronic cases of FCGS. If your cat does not improve significantly within 4 weeks after the initial dental cleaning procedure and extraction of any diseased teeth, then selective or full mouth extraction should be considered. This decision will be based initial findings of the full initial investigation including blood tests and severity of the disease. Full and caudal teeth extractions is not a procedure for every veterinarian. It is essential to have dental radiography performed to assess the underlying anatomy of each tooth root, and additionally to obtain after the extraction has been performed to ensure all components of the tooth roots have been removed. It is a delicate procedure that requires patience and skill from the veterinarian and a carefully managed post-operative pain management plan. We routinely accept both referral patients from vet hospitals around Perth and first opinion cases for this procedure.

How does it work?

It is thought that full or selective dental extraction helps cats by the removal of a significant ongoing bacterial burden in the mouth, which stimulates the inflammatory response in the oral mucosa and gingiva. Plaque and bacteria accumulate very quickly on teeth, and then act as an ongoing significant reservoir of continued antigenic stimulation in the mouth.

Which teeth are extracted?

Depending on findings of your cat’s initial investigation, it may be recommended to extract all caudal teeth and preserve canines and incisors (selective/caudal extraction) or to extract all teeth (full mouth extraction). The decision to preserve canines and incisors will be based on the severity of the inflammation, health of the canines and incisors, concurrent health conditions and anaesthetic time. If the canine teeth remain, ongoing daily disinfection with chlorhexidine will often still be recommended. Canine teeth and incisors may need extraction at a later stage if the disease is not responding to selective mouth extraction.

What is involved with surgery

Under anaesthetic all teeth are examined, probed and radiographed. All teeth are scaled and polished and the mouth is rinsed with an antiseptic solution. Local nerve blocks are applied, and opiate pain relief will have been administered prior to the surgery.

All caudal teeth and any retained tooth roots are extracted surgically. If the canines and incisors appear healthy they may be preserved as discussed above. For some patients the extractions are staged, performing one half of the mouth extraction at a time. Gingival flaps are made, and bone near the tooth roots is removed with a burr to facilitate extractions. It is critical that all roots are completely removed and therefore post-operative radiographs must be taken to ensure no roots remain. The bone is smoothed, flushed with saline and gingiva sutured with fine dissolvable suture material. Full mouth extraction is a procedure best performed by a veterinary team that are highly experienced in the procedure to minimise complications.

Post-operative multimodal pain relief is given. Antibiotics are administered intravenously during surgery and post operatively.

Post-Operative Recovery

Your cat will be hospitalised until eating and appearing comfortable. Most cats will require hospitalisation overnight and often feel comfortable enough by the following day to go home. Rarely some cats will require hospitalisation for several days and may even require a temporary feeding tube placed, however this is luckily not often the case.

Once the mouth is healed, cats usually can eat very well without teeth, indeed many are still able to eat dry food, as it can be swallowed whole.

Full or caudal mouth extraction is a big surgery, and often one month is required for the mouth and extractions sites to heal fully. The FCGS associated mouth inflammation will usually take several weeks to months to gradually improve, and post-operative anti-inflammatory medications such as prednisolone, interferon or cyclosporine may be prescribed during that period. In some cats it may take up to 2 years to achieve maximal resolution of symptoms.

Complications

As with any surgery, complications can occur: Difficulty in removing tooth roots, post-operative bone infection, soft tissue trauma, jaw bone trauma, and dehiscence of sutured wounds are some of the complications that may occur.

However the most common complication is a fever in the first 24 hours and temporary discomfort post operatively. This is managed with multimodal pain relief and supportive care until.

Prognosis

The good news is that the majority of cats (up to 80%) improve with full or selective mouth extractions.

A small percentage of cats will require ongoing medical treatment to control inflammation for the rest of their life, and there are some patients that are refractory to all treatments. Cats with caudal stomatitis, FIV or FeLV positive cats, and those affected by ongoing chronic severe FCGS have a poorer prognosis.

It is important to understand that only 29% of cats achieve complete remission with full mouth extractions. Often some visible inflammation may still remain, however the ultimate aim is to achieve a result where your cat is as comfortable as possible, able to eat comfortably, groom, and lead a happy life as part of your family.

Other options as adjunctive treatments to FCGS:

Food trial – As food allergy may be implicated, some practitioners advocate a food elimination trial as part of management of FCGS, however in practice few cases seem to respond to a food trial.