NEW APPROACH TO PRURITIC OTITIS
Steven A Melman VMD
Founder, DermaPet, USA
www.dermapet.com
dermapet@aol.com
Ear cases comprise almost 20% of total small animal office visits in the US. Adapting a comprehensive clinical trial for pruritus with a logical method for treating almost all cases of otitis (externa and media) will address the treatment of the overall case.
Seven Steps to Ear Therapy
The 7 steps to treating ear disease is a practical, clinical method to plug into one of the most common clinical problems veterinarians face every day.
Step 1. Clean. The author prefers an acetic/boric acid
cleanser which works to clean and treat Malassezia, Staphylococcus and Pseudomonas
infections. In many cases, daily cleansing for one week is all that is necessary.
Maintenance cleansing twice weekly should prevent a recurrence.
Step 2. If inflammation. Step 2 plus add short term and short acting
corticosteroids at anti-inflammatory doses.
Step 3. If bacteria with or without Malassezia are present then use a systemic flouroquinolone
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Gemish
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Step 4. Step 3 plus ear cleansing under anesthesia. Visualization of
the ruptured ear drum or swollen tympanum should confirm otitis media. After
careful and thorough cleansing and removal of "debris", infuse Baytril
or appropriate antibiotic and dexamethasone** directly
into the tympanum. In the case of a strangulated canal, with a 1 1/2 inch 20
gauge needle, inject approximately 1/2 ml of methyprednisolone acetate (depending
on the size of the pet) as deep as you can between the skin and the cartilage
of the ear canal. If a corticosteroid injection is not done then, if there is
significant erythema or exudation, then place the dog on short term (7-12 days)
short acting corticosteroids. At this stage, some people do culture sensitivity.
Step 5. Step 4 plus Culture and sensitivity.
Step 6. Protocol for Bacterial Otitis/Otitis Media
1. Systemic fluoroquinolones or start antibiotic which cultures sensitive systemically
for at least 45-60 days.
2. Clean with TrizEDTA twice daily.
3.Instill Baytril in either a TrizEDTA gemish (12 ml of TrizEDTA
and 50-100 ml of Baytril injectable) or diluted with saline. For first three
weeks add 6mg
dexamethasone SP.
4. For the first 14 days, I would use systemic prednisone at 1-2
mg/kg if OM is diagnosed. The rationale is to decrease the inflammation, mucous
secretion from
the mucoperiosteum, pain and viscosity of the exudate in the tympanic cavity.
5. If OM is diagnosed, I would anesthetize and with visualization
flush the ear with TrizEDTA and directly instill Baytril and NaDex phosphate
into the
tympanum. If the tympanum is present and OM is suspected then I would do a MYRINGOTOMY.
The location of the myringotomy should be ventral. Maintenance therapy would
include biweekly TrizEDTA cleansing long-term.
Step 7. Surgery.
Pruritic Clinical Trial
The following is a plan to both eliminate pruritus and determine its cause in most cases.
1. Shampoo Therapy: Shampoo daily with a hypoallergenic shampoo.
Removal of the offending antigen from the coat is fundamental. If pruritus is
severe, then use an oatmeal shampoo instead of the hypoallergenic. After bathing
(or on a dry animal), use a leave-on oatmeal conditioner.
2. Prescribe 180 mg/10 pounds of EPA (eicosapentaenoic acid).
3. Follow a strict hypoallergenic diet for 30 days. Home-cooked, all vegetable,
turkey, or lamb diet with rice-is preferable. A copy of a home cooked diet is
available in "Food Allergy" a chapter by Kevin Byrne in Skin Diseases
of Dogs and Cats, Melman, DermaPet and "Diagnosis and Treatment of Pruritic
Ear Diseases", a chapter in Small Animal Ear Diseases: An Illustrated Guide
by Lou Gotthelf, Saunders, 2000.
4. Low-dose, short-acting corticosteroid use. It is important to stop corticosteroids
at 10-12 days and not restart them until the trial is over.
5. Antibiotics are only used if a pyoderma is present. (cephalexin 10mg/#/BID/21d)
6. Treat phantom endoparasites with an anthelminthic that also targets whipworms.
7. Treat ectoparasites (Scabies and fleas). Begin a flea-control program. Since
frequent bathing is recommended, a compound that is supposedly not washed off
or
neutralized by shampooing, such as fipronil or imidicloprid, is preferable.
The advent of selamectin (Revolution) affords the clinician a single treatment
to eliminate fleas and scabies. Some may still wish to use lvomec (ivermectin)
0.1 ml/10lb weekly for four weeks. The extralabel use of this drug requires
informed consent of the client.
8.Treat Malassezia topically.
9. Bank serum for an allergy test since corticosteroids may interfere with most
tests.
Gotthelf L and Young S: A New Treatment for Canine Otitis Externa: Vet Forum,
August, 1997.
Melman SA. "Diagnosis and Treatment of Pruritic Ear Diseases"
Chapter in Small Animal Ear Diseases: An Illustrated Guide by Lou Gotthelf,
Saunders, 2000.
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