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Home , Ceruminous gland, Miconazole, Silver sulfadiazine

Chronic and recurrent otitis is Management of Otitis frustrating! • Otitis externa is the most common disease in the cat and dog • Reported incidence is 10-20% in the dog Lindsay McKay, DVM, DACVD and 2-10% in the cat [email protected] • It is a common reason for referral to VCA Arboretum View Animal Hospital dermatology specialists and very common clinical problem for general practitioners

1- Primary causes- directly Breaking down the problem induce otic inflammation • (atopy and food allergies) • Step 1- Identify the primary cause of otitis • Parasites (Otodectes cyanotis, Demodicosis) • Step 2- Assess for predisposing factors of • Masses (tumors and polyps) otitis • Foreign bodies (ex plant awns, , • Step 3- Treat the secondary ceruminoliths, hardened medications) • Step 4- Identify the perpetuating factors of • Disorders of keratinization (hypothyroidism, otitis primary seborrhea, sebaceous adenitis) • Immune mediated disease (pemphigus, juvenile cellulitis, vasculitis)

What are most common causes of 2- Predisposing factors of ear disease recurrent otitis…. • These factors facilitate inflammation by changing • Allergic disease in the dog- over 40% cases environment of the ear! in one study • Ear conformation- stenotic • Polyps and ear mites in the cat canals, hair in canals, pendulous • Excessive moisture or cerumen production • Treatment effects- irritation from meds/contact or trauma from cleaning

1 3- Secondary bacterial and/or 4- Perpetuating factors- prevent yeast infections the resolution of otitis • Epithelial thickening, • Address with ear glandular hypertrophy cleaning, topical • Dermal fibrosis, antimicrobial agents, cartilage mineralization most often topical and in some • Stenosis of lumen cases systemic anti- • OTITIS MEDIA infectives and systemic steroids

Otitis Externa Otitis Media Clinical Signs Physical Exam Findings • Head shaking • +/- Pinnal erythema and hair loss • Scratching/rubbing at ears • Erythema, swelling and • Otitis media- inflammation of the • Odor debris present in the external • Pain • Often an extension of otitis externa through a • Itchiness in other • +/- Ceruminous gland ruptured tympanic membrane locations hyperplasia • Ear drum appears normal and • May also occur from polyps or neoplasia intact within the middle ear • +/- Concurrent skin disease

Clinical signs of Otitis media Otitis media

• In dogs with recurrent ear infections for 6 Clinical Signs Physical Exam Findings months or longer, up to 82% had • Elevated third eyelid • Ruptured or intact tympanic 1 concurrent otitis media • Drooping lip on one side membrane • Intact membrane can be • AND in 71% of these cases of otitis media, • Parasympathetic nose- 1 bulging, hemorrhagic, the ear drum was intact at time of diagnosis unilateral hyperkeratosis discolored and exudate may • Treatment of otitis media often involves • Pain, odor, head shaking be visible greater than 6 weeks of systemic (any and all signs of otitis • Neurologic abnormalities- externa) Horner’s syndrome, facial • Deep ear flush under general anesthesia • Balance issues, head tilt (if nerve paralysis greatly aids therapy of otitis media concurrent otitis interna) • Neuro signs of otitis interna- peripheral vestibular 1. Saridomichelakis MN et al. Aetiology of canine otitis externa: a retrospective study • loss disease, and deafness of 100 cases. Vet Derm 2007; 18: 341-347

2 Otoscopy Otoscopy • Evaluate both ears Normal – Use separate cone for each ear – Ear pinnae – Vertical ear canal • Horizontal and vertical canals – Horizontal ear canal – Sebaceous glands- associated with HF, density greatest proximally – “Noxon’s Ridge” – Ceruminous glands- greatest density deep in ear canal – Tympanic membrane – Hair follicles- decrease in number distal to proximal (outside to inside) – There are a few fine at entrance of external Noxon’s Ridge acoustic meatus, serve as helpful landmark for locating the

A normal ear is self cleaning! Otoscopy Normal • Epithelial migration- epithelium in the ear canal grows outward from the tympanic membrane toward opening of the external • Horizontal and vertical canals ear canal – Light pink – Smooth • Epithelial cells carry debris with them – Minimal exudates • When this is disrupted, we can see ceruminoliths – Vertical canal 5-10 mm diameter where it meets • Ear canal masses also interrupt self cleaning horizontal canal

Otoscopy Otoscopy Abnormal Normal • Glandular hyperplasia – Acute: • Tympanic membrane • Enlargement and – Pars flaccida hypersecretion

• Upper quadrant – Chronic: • Elongated, full of colloidal • Pink with small vessels cellular debris • Little secretory activity, duct openings plugged • Loosely attached

3 Otoscopy Normal Canine Otoscopy Normal Feline • Tympanic membrane • Manubrium of – Pars tensa is straighter in cats • Pearl-gray • Thin • Radiating bands • Tough – Manubrium of malleus (stria mallearis is outline of manubrium of malleus that can be visualized Curve points towards through membrane) the nose!

Otoscopy Otoscopy Abnormal Abnormal • Ceruminolith • Mass behind tympanic • Mass membrane

• Foreign Body • Abnormal tympanic membrane • Inflammation • Ruptured tympanic • Excess exudates membrane

Tympanic Cavity

DOG CAT DOG CAT • Divided into 2 cavities by an • Consists of small almost complete bony septum epitympanic recess and • Larger cavity is the large ventral bulla ventromedial compartment • There is incomplete bony • To gain access you would need septum (Rosychuk’s Ridge) to break down this bony that allows communication septum = likely nerve between dorsal and ventral damage!! cavities • Leave that to surgeons! Refer for VBO if imaging shows mass or exudate there!

4 Therapy of otitis externa Therapy of otitis media 1- Keep ear canal clean 1- Keep ear canal clean 2- Topical and/or systemic anti-inflammatory therapy 2- Topical anti-inflammatory therapy 3- Topical antibiotics/ antimicrobials 3- Topical antibiotics/ antimicrobials 4- Systemic antibiotics and/or 4- TREAT THE UNDERLYING CAUSE 5- Deep ear flush and otoscopy under general 5- Monitor response to therapy with recheck anesthesia exams and otic cytology 6- TREAT THE UNDERLYING CAUSE 7- Monitor response to therapy with recheck exams and otic cytology

1- Keep the ear clean 1- Keep the ear clean • Ear cleanser options: • Removes the nidus (ex. cerumen) of o Epiotic Advanced- creates acidified ear • Removes bacterial and inflammatory debris canal • Allows antimicrobials to penetrate the entire o Douxo Micellar or ear canal Cerumene- • Prevents purulent debris from inactivating ceruminolytics antimicrobial agents, especially important for • Clean every 1-2 days

Ear cleaning instructions for Following cleaning, presoak with owners- the gauze method Triz EDTA • 3 by 3 gauze • Indicated in bacterial • Wet gauze with cleaner or infections, especially when pour cleaner into canal rod shaped bacteria such as • Gently massage gauze into Pseudomonas present ear canals • Presoak the canal with Tris- • It wicks up debris and EDTA product prior to cleans ear gently medicating • Repeat until clean gauze • Do not wipe clean emerges • Tends to be very well • Done on a daily basis, prior tolerated! to medicating ear

5 2- Topical and Systemic Steroids 3- Topical therapy yeast otitis • Unless medically contra-indicated, always • Topical antifungals- miconazole, treat otitis externa with topical steroids , • In preparation for deep ear flush and/or • Can be used alone, or in conjunction with painful swollen ears- add 2-3 week course steroids of oral • Treat over 3-4 weeks with topical therapy • Steroids decrease inflammation and • In otitis externa/ media, treat until external production of cerumen, reduce swelling and canal cytology is negative stenosis of canal, and make pets less painful

3- Topical therapy- topical recipes bacterial otitis • Miconazole 2% (1.5 to 3ml) with Synotic • First time infections- cocci- , (8ml bottle) florfenicol, Polymixin B or orbifloxacin are • Miconazole 2% (20 ml) with good choices 2 mg/ml (5-10ml) • First time infections- cocci, rods- gentamicin, • Clotrimazole can be substituted enrofloxacin, orbifloxacin and Polymixin B • Treat for 3-4 week period • Important to recheck prior to end of therapy to ensure that infection has resolved

The role of Pseudomonas in canine otitis Clinical Signs- Pseudomonas otitis

• Pseudomonas aeruginosa- aerobic, gram • Head shaking or negative rod bacteria scratching • Associated with chronic otitis externa and • Purulent exudate media in the dog • Malodor • Swelling, • Isolated in up to 20% of dogs with otitis inflammation and pain • Rapidly develops multi-drug resistance • Ulceration • OTITIS MEDIA

6 Recognize biofilm when you see it Therapy of Pseudomonas otitis • Ear cytology from ear chronically infected with 1- Keep ear canal clean Pseudomonas aeruginosa 2- Topical antibiotics/ antimicrobials toxic neutrophils, numerous rod bacteria, some within colonies 3- Systemic antibiotics in the dark purple material 4- Deep ear flush and otoscopy under general which is biofilm anesthesia • Culture and sensitivity is indicated for most cases where 5- Topical and/or systemic anti-inflammatory rods are seen and especially if therapy biofilm noted • Start preparing owner for deep 6- TREAT THE UNDERLYING CAUSE ear cleaning

Pseudomonas ear infection Antibiotics with potential activity Ear cytology with rod bacteria present against Pseudomonas Collect deep swab for bacterial culture and sensitivity Class Specific antibiotic Aminoglycosides Gentamicin, , , Otoscopy +/- sedation Tobramycin Fluoroquinolones Marbofloxacin, , Ear canal mildly hyperplastic; Ear canal severely hyperplastic; Ear drum +/- visible Unable to see ear drum Enrofloxacin Polypeptides Polymixin B 2 mg/kg for 10-14 Carboxypenicillins Ticarcillin, Timentin, Carbenicillin Ear drum normal; days to reduce inflammation Treat topically and systemically 3rd generation Ceftazidime OR If inflammation reduced, proceed cephalosporins Ear drum abnormal or absent; with deep ear flush; if ear Miscellaneous Proceed with deep ear flush canal is still obstructed, consider Disclaimer: Recipes formulated by dermatologists, not pharmacologists! surgical management

Products with reduced risk of Issue of ototoxicity ototoxicity • Aminoglycosides, polymixins, , • Ciprofloxacin • Clotrimazole ceruminolytics (except Cerumene), and cleaners • Enrofloxacin • Miconazole with alcohols are all potentially ototoxic • Ticarcillin • • When the aminoglycosides are used topically, the • Timentin • Cerumene risk of toxicity may be overestimated • Dexamethasone • Likely Douxo Micellar • Use of ototoxic med justified when guided by and Epiotic culture, a safer alternative is not available, and the • owner has been notified of the potential risks

7 3- Topical therapy Amikacin solutions

Enrofloxacin: • T8 solution (26.9ml), dexamethasone- 4 mg/ml 1- Epiotic (6ml), Dexamethasone- 4 mg/ml (2ml), (2ml), Amikacin- 250mg/ml (1.1ml) = 1 oz. Baytril- 22.7 mg/ml (2ml), +/- Miconazole- 1-2% • Saline (27ml), dexamethasone- 4 mg/ml (1ml), lotion (2ml) = ½ oz. bottle Amikacin- 250mg/ml (1ml) = 1 oz. 2- Tris EDTA solution (26.1ml), Baytril- 100mg/ml (2.9ml) = 1 oz. bottle 3- Synotic (8ml bottle)- add 1.5- 3ml of Baytril +/- Miconazole- 1.5ml (bottle has room for 3 extra mls)

Ceftazidime Silver sulfadiazine solutions

• Ceftazidime- reconstitute 1 gram bottle with • 1% SS cream (1.5ml) and distilled water 40 mls of saline, add 4 mls of (13.5ml) = ½ oz. dexamethasone (4 mg/ml) • Saline (24ml), Dexamethasone- 4mg/ml • Refrigerate! (2ml), 1% SS cream (6ml) = 1 oz. • Saline (25ml) and 1% SS cream (3ml) = 1 oz.

4- Systemic antifungals for otitis media 4- Systemic antibiotics for otitis media • Yeast otitis media o Ketoconazole- 5- 10 mg/kg q 12-24 hours • Bacterial otitis media- USE C/S!! o - 5-10 mg/kg q 12-24 hours  Enrofloxacin- 10- 25 mg/kg SID  Marbofloxacin- 2.75- 5.5 mg/kg SID - 5-10 mg/kg q 12-24 hours o  Ciprofloxacin- 25-30 mg/kg SID o Terbinifine- 30 mg/kg q 12 hours  Cephalexin- 22- 30 mg/kg BID  Cefpodoxime 5-10 mg/kg SID  - 11 mg/kg BID

8 What are the options when no 5- Deep ear flush- Indications oral drug is available? • Cases of bacterial otitis externa/ media • Failure to clear infection with home cleaning when the bacteria are only sensitive to • Relapse of infection despite home cleaning systemic injectable medications • Purulent exudate/biofilm associated with many • Consider parenteral therapy- often declined G(-) infections such as Pseudomonas sp. by owner due to cost, side effects and/or • If there is suspicion of otitis media, foreign body frequency of injections or neoplasia • ALLOWS FOR FULL EVALUATION OF THE • However, success has been achieved with EAR CANAL AND EAR DRUM, SAMPLING deep ear flush and topical therapy alone FOR C/S OR HISTOPATH AND CLEANSING

Deep ear flush- preparation Video Otoendoscopy • Familiarize yourself with normal otic • Radiographs, CT or MRI may be indicated to assess for ear canal mineralization, assess for neoplasia and extent of disease • General anesthesia and intubation are a must! • Collect ear cytology +/- external ear culture • Soak external ear canal with ceruminolytic ear cleaner like Douxo or Cerumene to remove large debris and exudate

Ear flushing technique A few helpful tools… • Examine tympanic membrane • Myringotomy- caudoventral aspect of the pars tensa- using 3.5 or 5 Fr polypropylene catheter or small culturette • Collect for culture using sterile swab or via aspirate of fluid from middle ear cavity • Collect cytology via similar methods • Can be done with Video-otoendoscope or Hand- held otoscope

9 Ear flushing technique Complications of deep ear flush • Once all samples have been obtained, flush middle • Most are transient, more often ear repeatedly with sterile saline or distilled water in the cat than in the dog • At end of procedure can infuse bullae with • Pain and head shaking injectable dexamethasone and/or non ototoxic injectable antibiotic • Horner’s syndrome, facial nerve paralysis, vestibular • Healing of the tympanic membrane in dogs- 21-35 disease and deafness days • Systemic steroids post • Healing of the tympanic membrane in cats- smaller procedure and gentle perforations heal in about 25 days, larger ones take technique can limit these up to 60 days complications

6- Treat the underlying cause

• Non-seasonal otitis- start a food trial • Seasonal otitis- consider allergy testing and Questions?? allergy vaccine or symptomatic therapy • Do other dermatologic findings point to other underlying diseases? [email protected] • Discuss maintenance therapy- prepare your owners for needs of their pet’s otic disease based on residual persisting changes (WE CANNOT TURN BACK THE CLOCK!)

References

1. Saridomichelakis MN et al. Aetiology of canine otitis externa: a retrospective study of 100 cases. Vet Derm 2007; 18: 341-347 2. Cole LK, et al. Microbial flora and antimicrobial susceptibility patterns of isolated pathogens from the horizontal ear canal and middle ear cavity in dogs with otitis media. JAVMA 1998; 212: 534- 538 3. Steiss JE, et al. Healing of experimentally perforated tympanic membranes demonstrated by electrodiagnostic testing and histopathology. JAAHA 1992; 28: 307-310

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