Refractory Chronic Gingivostomatitis in Cats
Feline Chronic Gingivostomatitis is a very serious and painful condition in cats. There is a great deal we do not know about the causes of this condition and there remains a lot of mis-information regarding what it is and how to manage it. I have my paper on what to do with affected cats that still have teeth (http://www.toothvet.ca/PDFfiles/fcgs.pdf). The first and most important thing to do for these cats is to remove every scrap of every root of of every tooth. But what about cats who continue to have severe and painful inflammation after whole-mouth extraction?
My friend and colleague, Dr. Eric Davis, DVM, DiplAVDC, recently posted his thoughts on this and has given me permission to share them here.
So that we all are on the same page, let us define refractory chronic gingivostomatitis (RCGS) as those cases in which oral mucositis and pain persists despite complete exodontia. Because of the thousands of different taxa present in the oral cavity including bacteria, archaea, phages and other viruses, candidate phyla radiation (CPR which are microbacteria that parasitize bacteria, protozoa, and fungi including yeasts) I think that antimicrobial therapy designed to target specific oral taxa (bacteria, yeast/fungi) is less likely to resolve RCGS than is reducing the severe and inappropriate inflammatory response using immunosuppressive therapy. I consider RCGS to be a life-threatening condition that needs to be managed similar to treatment for immune mediated hemolytic anemia (IMHA). The run-away train of unremitting inflammation must be stopped.
Currently, cyclosporine and corticosteroids are the most commonly used immunosuppressant agents (although there are others). A common error in using corticosteroids (prednisolone) is that anti-inflammatory doses rather than immunosuppressive doses are typically prescribed. In cats, prednisolone at 1-2 mg/kg/day is an anti-inflammatory dose, while 2-4 mg/kg/day of prednisolone is an immunosuppressive dose. Cats are much more tolerant of prednisolone than are humans and dogs. The protocol I use is listed in Plumbs in which a 50% reduction in the dose is given every 20 days. In my hands, most cats have resolution of caudal mucositis and pain. The occasional cat requires every other day medication before tapering is complete. The occasional cat may have a flare-up in which case the immunosuppressive protocol is re-instituted.
I have prednisolone prepared by Wedgewood Pharmacy in the form of Twist-a-Dose or EZ-Dose transdermal pens. There is a perforated sponge at the tip of the pen, and two revolutions of the device delivers the correct amount of the medication. The cream is applied to the inside (furless) surface of the ear pinna. That way, the mouth does not need to be handled which is much appreciated by the patient, owners, and me. If the pain is very severe, I use transdermal fentanyl patches which come in 12 ug/hr or 25 ug/hr sizes.
I’m not a cyclosporine (CSA) guy although many Dips are happy with it. The research has shown that absorption is highly variable from individual to individual. If not enough medication, the signs of stomatitis will persist, but that is usually clinically obvious. The problem is if CSA is absorbed rapidly or if the patient is a very good absorber. Fulminant toxoplasmosis and malignant neoplasia have been reported in cats that are immunosuppressed with CSA.
Eric Davis, DVM, DiplAVDC