My 9 year old cat has Eosinophilic Granuloma Complex, mostly in the mouth and tongue area. His Vet has treated him with an injection of dexamethasone 2 mg. when the out break is at it's worst. I need to give him a 5 mg tab of Prednisolone every other day to keep it under control. However the Prednisolone does not seem to be keeping it in check as well as it did in the past. Is there any new or update treatment for this condition?
I have attached a "cut and paste" from Dr. Hnilica, who is a dermatology expert veterinarian and works in a university setting - has all the latest treatments listed. The primary thing is initiating a strict flea prevention program and dosing your cat every 3 weeks instead of every 4 as recommended on the label. Antihistamines are a good alternative to try and many of them and their doses are listed below. I would say that the newest treatment for this condition is cyclosporine, or Atopica, which is used once daily for 8 weeks and then given once or twice weekly.
The information below is a little technical, so if you have questions after looking at it, let me know and I'll explain further. But it is a very through coverage of all possible treatments available from a leading expert in the field.
** I don't know why the blue boxes are there, but I can't seem to delete them***
The best option for long-term control of the eosinophilic lesions is to identify and control all underlying/ primary diseases. Based on the diagnostic work-up, any opportunity to eliminate or avoid possible allergenic etiologies should be taken. If flea allergy or food hypersensitivity can be identified then the lesions can be controlled in these patients by avoiding exposure to the offending allergens. For cats that do not have a primary disease identify, empiric therapies must be used to control the clinical symptoms.
Flea control is an essential first step
Many cats are extremely effective at removing fleas and flea dirt by grooming making it difficult to prove the existence of a flea infestation. Therefore, all pruritic cats should be treated aggressively for possible flea allergy dermatitis.
Frontline Plus and Advantage work exceptionally well.
Due to grooming and limitations of the products, treatments should be applied every 2-3 weeks in allergic cats.
In heavily infested environments, it may take multiple weeks to reduce the number of emerging fleas. Owners may perceive this as lack of efficacy when in fact it is caused by the large number of fleas in the pupal stage.
Indoor cats must be treated year-round.
Amitriptyline (Elavil): 5-10 mg/cat q 12-24 hours
Chlorpheniramine (Chlor-Trimeton): 2-4 mg/cat q 12-24 hours
Clemastine (Tavist): 0.68 mg/cat or 0.05 mg/kg q 12 hours
Cyproheptadine (Periactin): 2 mg/cat or 1.1 mg/kg q 12 hours
Diphenhydramine (Benadryl): 2-4 mg/cat q 8-12 hours
Hydroxyzine (Atarax): 5-10 mg/cat or 2.2 mg/kg q 8-12 hours
Trimeprazine (Temaril): 0.5-1 mg/kg q 8-12 hours
Cetirizine (Zyrtec): 5 mg/cat q 12 hours
Fexofenadine (Allegra): 10 mg/cat q 12 hours
Essential Fatty acids
Oral essential fatty acid supplements may be helpful. A beneficial effect should occur within 3-4 weeks of initiating therapy. A synergistic effect may be seen when essential fatty acid supplements are given in combination with glucocorticoids or antihistamines.
TMS (120 mg / cat given every 12 hours) may be effective in reducing the immunologic response. The active metabolites of sulfones have a variety of anti-inflammatory effects. Studies demonstrated that sulfones reduce eosinophil activation and inhibit myeloperoxidase and eosinophilic peroxidase. The ability to reduce the reactivity of eosinophils and the production of eosinophilic secretory products can directly reduce the eosinophil's ability to cause tissue destruction and promote an inflammatory response.
Doxycycline/Tetracycline possess anti-inflammatory effects and have been useful in treating a variety of immune mediated dermatoses. Although clinical studies are lacking, these antibiotics may offer a treatment alternative with relatively few adverse effects.
To induce remission give methylprednisolone acetate 20 mg/cat or 4 mg/kg SC q 2-3 weeks, or give prednisone 2 mg/kg PO q 12 hours until lesions resolve (approximately 2-8 weeks).
Intralesional steroid injections with methylprednisolone acetate or triamcinolone may be useful for severe lesions: especially oral eosinophilic granulomas.
For long-term control of recurring lesions:
Repositol methylprednisolone acetate 20 mg/cat or 4 mg/kg SC or IM q 2-3 months as needed.
Triamcinolone acetonide 5 mg/cat SC or IM q 2-3 months as needed.
Prednisone 2 mg/kg PO q 24 hours until pruritus and lesions resolve (approximately 2-8 weeks), then 2 mg/kg PO q 48 hours for 2-4 weeks, then taper down to lowest possible alternate-day dosage if long-term maintenance therapy is needed.
Treatments for specific etiologies
Immunotherapy (allergy shots) is indicated if medical therapy is ineffective or results in undesirable side effects. Clinical improvement is usually noted within 6-8 months, but can take up to 1 year in some cats.
Avoid offending dietary allergen(s). Feed a balanced home-cooked or commercially-prepared hypoallergenic diet.
Avoidance, desensitization, or symptomatic treatments
Remove and avoid exposure to the offending agent.
Treatments with potential adverse effects
Cyclosporine (25 mg / cat every 24 hours on an empty stomach). Treat for 8 weeks then attempt to taper the dosage to an every other day schedule.
Chlorambucil 0.2 mg/kg PO q 24-48 hours may be able to eliminate the lesions but adverse effects are serious and common. Patients should be closely monitored during the treatment period.
Aurothioglucose 1 mg/kg IM q 7 days until remission (8-20 weeks) then 1 mg/kg Im q 4 weeks. This treatment is uncommon but reports have suggested some benefit.
Progestin compounds (OvabanR) can reduce the size and severity of the lesions but adverse effects (diabetes, mammary hyperplasia, and mammary adenocarcinomas) are common.
Radiation therapy can provide dramatic reduction in the size and severity of the lesions (especially for indolent ulcers). A strontium probe is used to apply local radiation to the superficial tissue. As the lesions regresses, additionally treatments are needed to bring about complete resolution. Since, the primary etiology is not being eliminated, repeated treatments may be necessary to control relapses.
Laser and cryosurgical techniques can reduce the size and severity of some lesions but recurrence is common.
Cats respond to a variety of antigenic stimuli with an eosinophilic cellular infiltrate. This reaction demonstrates clinically as the one of three common clinical cutaneous lesions patterns (miliary dermatitis, alopecia, and eosinophilic granuloma complex).
By using historical and clinical clues, a prioritized differential list can be used to guide the diagnostic work-up.
The best option for long-term control of the eosinophilic lesions is to identify and control all underlying/ primary diseases. For cats that do not have a primary disease identify, empiric therapies must be used to control the clinical symptoms.
1. Small Animal Dermatology: A Color Atlas and Therapeutic Guide. Medleau L and Hnilica K. WB Saunders, 2001.
2. Muller and Kirk's Small Animal Dermatology, 6th Ed. Scott DW, Miller WH, and Griffin CE. WB Saunders, 2001.
Keith A. Hnilica, DVM, MS, Dip ACVDAssistant Professor, DermatologyUniversity of TennesseeKnoxville, TN "
Hope this helps you.
Full time practicing companion animal veterinarian.
Reply to Dr. Debbie's Post: Thank you, XXXXX XXXXX Your information was very helpful. I didn't know there were so many treatments. I will take this to my cat's Vet and see if there is something else we can try. We already ruled out the food sensitivity and we do know he has a flea allergy but his Vet never tryed any other treatment than what I discribed.