Surolan for Dogs & Cats: Dosage Guide, How to Apply It Correctly, the Eardrum Warning & How It Compares to Easotic and Otomax

Surolan is one of the most widely prescribed ear drops for dogs and cats with otitis externa. Its triple combination of miconazole (antifungal), polymyxin B (antibiotic), and prednisolone (anti-inflammatory) addresses the three key elements of ear infection simultaneously. But using it correctly — and knowing when NOT to use it — is critical.

This guide covers how Surolan works, the correct dosage, the step-by-step application technique, the ruptured eardrum warning, and how it compares to the other two major combination ear drops: Easotic and Otomax.

What’s in Surolan and What Does Each Ingredient Do?

Surolan is a suspension (shake before use) containing three active ingredients per ml:

• Miconazole nitrate 23mg/ml — antifungal that kills Malassezia pachydermatis yeast by blocking ergosterol synthesis in the fungal cell membrane. Also active against Gram-positive bacteria.
• Polymyxin B sulphate 0.5293mg/ml — polypeptide antibiotic that kills Gram-negative bacteria by disrupting their outer membrane. Covers the bacterial spectrum that miconazole doesn’t reach.
• Prednisolone acetate 5mg/ml — glucocorticoid corticosteroid that reduces the inflammation, swelling, pain and itch in the ear canal.

Inactive ingredients: colloidal silicon dioxide and liquid paraffin.

Why Does Otitis Externa Need Three Different Active Ingredients?

Ear infections in dogs and cats are almost never caused by a single organism. The vast majority of cases involve mixed yeast and bacterial infections simultaneously — and the inflammation that results from those infections makes the condition more painful and creates an environment that encourages further microbial growth.

Miconazole alone would not treat Gram-negative bacteria. Polymyxin B alone would not treat yeast. Neither would relieve the itch and swelling that make the ear infection so distressing. Prednisolone alone would suppress inflammation but do nothing about the underlying infection. Surolan combines all three to address all components in a single treatment.

The Synergy Between Miconazole and Polymyxin B

This is a clinically important detail that most product descriptions omit. In vitro studies have demonstrated a synergistic antimicrobial effect between miconazole nitrate and polymyxin B sulphate — the two work better together than either does alone. The addition of prednisolone acetate to the combination does not interfere with this antimicrobial activity. This documented synergy is part of why Surolan’s clinical performance is strong against mixed infections.

What Infections Does Surolan Treat?

Surolan is indicated for otitis externa (outer ear infection) in dogs and cats caused by susceptible strains of:

• Malassezia pachydermatis — the primary yeast cause of canine and feline otitis externa. Typically presents as brown, waxy, coffee-ground discharge with a musty or yeasty smell. Very common in dogs with floppy ears, atopic (allergic) skin disease, or frequent swimming.
• Staphylococcus pseudintermedius — the most common bacterial pathogen in canine otitis. May produce more purulent (pus-like) yellow or yellow-green discharge.

The polymyxin B component provides additional cover against Gram-negative bacteria in mixed infections.

Surolan does not treat ear mites (Otodectes cynotis). Ear mites produce dark, crumbly discharge and are more common in cats and young dogs. If ear mites are suspected, a separate appropriate treatment is needed.

⚠️ The Most Important Safety Rule: Never Use Surolan With a Ruptured Eardrum

Before using Surolan — or any otic medication containing polymyxin B — the integrity of the tympanic membrane (eardrum) must be confirmed. Using otic polymyxin B preparations with a ruptured eardrum allows the drug to contact the middle and inner ear structures directly. This can cause permanent ototoxicity — irreversible damage to the cochlea and vestibular apparatus, resulting in deafness and/or balance disorders.

A perforated eardrum can occur from severe untreated infection, trauma, or inappropriate probing of the ear canal. Signs that may suggest perforation include:

• Head tilt
• Loss of balance or stumbling
• Abnormal eye movements (nystagmus)
• Sudden apparent deafness
• Pain on opening the mouth

If any of these signs are present, or if you are unsure, have a veterinarian examine the ear with an otoscope before instilling any ear medication. Do not probe or clean deeply without veterinary guidance.

Surolan Dosage and Step-by-Step Application

The approved dose is 5 drops per affected ear, twice daily, for 7 consecutive days.

Step-by-Step Application

1. Clean the ear canal first. Use a veterinary ear cleaner recommended by your vet. Gently remove debris and excess discharge, and allow the ear to dry before applying Surolan.
2. Shake the Surolan bottle well before each dose — it is a suspension that settles.
3. Count 5 drops into the affected ear canal. Hold the bottle vertically and count carefully. The suspension is thicker than water and drops fall more slowly — don’t squeeze the bottle, which makes dosing inaccurate. Avoid touching the bottle tip to the ear to prevent contamination.
4. Massage the base of the ear gently for 30–60 seconds after instillation. You should hear a squelching sound, which confirms the medication is being distributed down the ear canal to the horizontal part.
5. Allow the dog or cat to shake their head — this is normal and helps move the medication into position. Wipe any overflow from the ear flap.
6. Repeat twice daily for the full 7 days. Do not stop early if the ear looks better — incomplete treatment leads to relapse and resistance.

Contraindications and Safety

Do Not Use Surolan If:

• The eardrum is ruptured or suspected to be perforated (absolute contraindication)
• The animal is known to be hypersensitive to any ingredient
• The animal is receiving other ototoxic drugs, particularly aminoglycoside antibiotics (gentamicin, neomycin, tobramycin, amikacin) by any route

Use With Caution In:

• Breeding animals, pregnant, or lactating females (safety not established)
• Situations requiring repeated or extended courses beyond 7 days — prolonged topical corticosteroid use can cause adrenocortical suppression

Side Effects

• Local irritation — mild discomfort or increased head shaking immediately after application; usually transient
• Reduced hearing — temporary hearing reduction was reported in some dogs in the clinical field study; monitor closely and discontinue if hearing changes
• Deafness — reported in post-approval use in foreign markets; risk is primarily with ruptured eardrum (see above)
• Pinna reactions — red pustules or blisters on the ear flap reported rarely
• Systemic steroid effects — with treatment beyond the recommended 7 days at doses above label

Surolan vs Easotic vs Otomax: Which Should You Use?

All three are combination otic drops containing antifungal, antibiotic, and corticosteroid ingredients. The differences matter clinically:

Key consideration: Easotic uses gentamicin (an aminoglycoside) rather than polymyxin B as its antibiotic. Aminoglycosides have good activity against Pseudomonas aeruginosa, which can be a problem in chronic or resistant ear infections — polymyxin B also covers Pseudomonas but less reliably at the concentration in Surolan. For confirmed Pseudomonas otitis, Easotic or a culture-guided treatment may be preferred.

Easotic’s unique metered pump delivers an exact 1ml dose every time without counting drops, which owners often find easier and more accurate. However, Surolan’s approval in both dogs AND cats gives it an advantage in multi-species households.

Where to Buy Surolan

You can order Surolan Otic Suspension 15ml from PetShopBoss.com with free worldwide shipping.

Related: Easotic Ear Drops 10ml (dogs) | Full comparison: Easotic vs Otomax vs Surolan