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Feline Stomatitis: Medical Therapy for Refractory Cases

Evidence points to stomatitis being an immune-mediated disease rather than a bacterial infection. Here’s how to manage it.

Severe caudal stomatitis and residual rostral stomatitis is seen in a cat that had partial mouth extractions about one year earlier. The recommended approach to this case would be to extract any remaining teeth, radiograph for the presence of any retained root tips in the areas of missing teeth, and consider biopsy of the more severely affected right caudal oral mucosa.

JOHN R. LEWIS

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Originally published in the October 2014 issue of Veterinary Practice News

In a previous article, we discussed extractions as the gold standard treatment of feline stomatitis. Even after undergoing extractions, approximately 20 percent of patients will continue to experience clinically relevant signs of oral inflammation.

We call these “refractory” cases. The goal of treatment is to reduce or eliminate oral discomfort to a degree where appetite is consistently good and patient body weight is maintained.    

Attack Plaque

Recall that feline stomatitis is often an immune-mediated disease, due to an aberrant response of the immune system toward component(s) of dental plaque, likely bacterial antigens.1

If the patient still has teeth and the owner does not want them extracted, frequent professional dental cleanings (supra- and subgingival) will help to decrease plaque accumulation and inflammation.

Daily tooth brushing would help decrease plaque accumulation, but brushing is difficult in stomatitis cats—an understatement!—due to oral pain. Application of plaque retardant substances during professional dental cleanings might be considered to slow the rate of plaque accumulation.

Perioperative Medications for Oral Surgery Cases

Multimodal pain medication regimens are necessary when embarking on surgical extractions. Premedication with an injectable opioid is a good place to start.

Once the patient is under anesthesia, regional analgesia can be maintained with 0.5 percent bupivacaine placed as a deep infraorbital block (maxilla) or inferior alveolar block (mandible). The maximum safe dose of bupivacaine in cats (total dose, not per site) is considered to be 1.5-2.0 mg/kg.2

Bupivacaine regional blocks provide postoperative pain relief for  four to 10 hours. There is evidence that adding opioids, such as buprenorphine, to bupivacaine blocks allows for prolonged regional analgesia in the range of 24 hours in people undergoing oral surgery.3

Anti-inflammatory medications (NSAIDs or corticosteroids) may be considered either postoperatively or intraoperatively, depending on the patient’s concurrent medical conditions.

In stomatitis patients, I lean toward using corticosteroids over NSAIDs due to the anti-inflammatory, immunomodulatory and appetite-stimulant properties of steroids.

Postoperative pain mediations can take a variety of forms. Consideration should be given to ease of administration in a patient who recently had major oral surgery. Transmucosal buprenorphine is relatively easy for pet owners to administer, due to its small volume and absorption through the mucous membranes without the need to be swallowed.

Fentanyl transdermal patches (12.5 or 25 ug/hr) may be used in some feline stomatitis patients where risks of patch ingestion by pets or family members is unlikely.4

Opinions vary regarding use of perioperative antibiotics for stomatitis patients. If the patient has significant concurrent illness or suspected secondary bacterial infection, I will give an intraoperative dose of ampicillin at 22mg/kg IV, and possibly even a seven-day course of oral postoperative antibiotics such as amoxicillin-clavulanate or clindamycin.

Refractory Cases

After a stomatitis patient has extractions, don’t label that patient as refractory to treatment too soon. Remember, this is a chronic disease, and chronic diseases take time to fully resolve. During the process of extractions, we are removing the naturally occurring plaque-retentive surfaces (the teeth) and replacing them with a temporary plaque-retentive surface (the sutures).

Until these sutures fully dissolve, residual inflammation will be likely. Until the inflammation subsides, medical therapy will be necessary.

A first step in treatment of refractory stomatitis is to extract any remaining teeth and perform a dental radiographic re-examination of the dental arches to rule out the possibility of retained tooth roots.

If this has already been done or is declined by the pet owner, various medical therapies can be attempted. Historically, a variety of medications have been used to treat stomatitis, including gold salts (aurothioglucose), azathioprine, thalidomide, cyclophosphamide and megesterol acetate.

Today, corticosteroids, cyclosporine, interferon, antibiotics and various pain medications are the mainstays of chronic treatment.5

Prednisolone at 0.5-1 mg/kg PO q12-24h, with a slow taper of the dose over months to determine the lowest dose that controls clinical signs. If a patient won’t take oral medications, depot formulations may be given, but warn owners of risk of diabetes mellitus and congestive heart failure. Transdermal prednisolone formulations are available via compounding pharmacies and can be very effective in controlling clinical signs.

Cyclosporine (Neoral, 2.5 mg/kg PO q12h as a starting dose) shows promise in refractory cases, with up to 85 percent of cats showing improvement. Appropriate patient monitoring is critical when using cyclosporine to avoid serious and potentially fatal side effects.6

Recombinant feline interferon (Virbagen Omega [Virbac], not currently available in the U.S.) has been shown to decrease lesion size and pain when administered orally at a dose of 0.1MU daily.7

Azithromycin (5-10 mg/kg q24h for five to 21 days) has been advocated for treatment of Bartonella-seropositive cats. Long-term daily use of azithromycin should be approached cautiously because of its long half-life (35 hours) in cats.

Antibiotics (amoxicillin-clavulanate or clindamycin) in Bartonella-negative cats may provide transient improvement in acute cases.

Buprenorphine transmucosal administration (0.01-0.02 mg/kg sublingually q6-12h) provides good postoperative and chronic pain relief.

Gabapentin (5-10 mg/kg PO q8-12h) for chronic pain. Wean off slowly if discontinued after chronic administration.

Summary

Surgical treatment is preferred to medical management due to high cure rate and ability to avoid potential side effects of medical therapy. Avoid the temptation to treat with multiple rounds of various antibiotics in an attempt to find the “magic bullet.”

Evidence points to stomatitis being an immune-mediated disease rather than a bacterial infection. Treat with plaque-control measures (extraction being best), immunomodulator, and pain medications in chronic cases.

Nonsurgical options such as therapy laser and acupuncture will benefit from well designed, blinded, controlled studies to determine their true effectiveness.

References

1. Dolieslager SM, et al. The influence of oral bacteria on tissue levels of Toll-like receptor and cytokine mRNAs in feline chronic gingivostomatitis and oral health. Vet Immunol Immunopathol 2013;151:263-74.

2. Beckman, B, et al. Regional nerve blocks for oral surgery in companion animals. Comp Cont Educ Pract 2002;24:439-442.

3. Modi M, et al. Buprenorphine with bupivacaine for intraoral nerve blocks to provide postoperative analgesia in outpatients after minor oral surgery. J Oral Maxillofac Surg 2009;67:2571-2576.

4. Plumb’s Veterinary Drug Handbook. http://www.vin.com/doc/?id=4692227&pid=451

5. Lewis JR. Stomatitis. In: Cote E (ed). Clinical Veterinary Advisor, 2nd ed. Elsevier, St. Louis, 2011;1051-1053.

6. Lommer MJ. Efficacy of cyclosporine for chronic, refractory stomatitis in cats: A randomized, placebo-controlled, double-blinded clinical study. J Vet Dent 2013;30:8-17.

7. Hennet PR, et al. Comparative efficacy of a recombinant feline interferon omega in refractory cases of calicivirus-positive cats with caudal stomatitis: a randomised, multi-centre, controlled, double-blind study in 39 cats. J Feline Med Surg 2011;13:577.

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