Surolan Otic Suspension 15ml (Miconazole 23mg/ml + Polymyxin B + Prednisolone) – Ear Infection Treatment for Dogs & Cats

What Is Surolan?

Surolan is a veterinary otic (ear) suspension manufactured by Elanco Animal Health, combining three active ingredients in a single formulation to treat otitis externa (outer ear infection) in dogs and cats. Each ml of Surolan contains:

• Miconazole nitrate 23mg/ml — a synthetic imidazole antifungal with broad activity against yeasts and fungi, and additional antibacterial activity against Gram-positive bacteria
• Polymyxin B sulphate 0.5293mg/ml — a polypeptide antibiotic with bactericidal activity against Gram-negative bacteria
• Prednisolone acetate 5mg/ml — a glucocorticoid corticosteroid that reduces inflammation, swelling, pain and itch in the ear canal

Inactive ingredients: colloidal silicon dioxide, liquid paraffin. Surolan is presented as a suspension — shake well before every use.

The Three-Ingredient Approach — And Why Synergy Matters

Otitis externa in dogs and cats is rarely caused by a single pathogen. The overwhelming majority of cases involve a mixed infection of yeast and bacteria simultaneously, compounded by the inflammation and swelling those infections create. A single-agent treatment would only address part of the problem. Surolan addresses all three elements at once:

Miconazole Nitrate — Antifungal + Gram-Positive Cover

Miconazole blocks ergosterol synthesis in fungal cell membranes, causing the membrane to collapse and the fungal cell to die. It is highly active against Malassezia pachydermatis — the yeast that causes the majority of canine and feline ear infections. It also has direct antibacterial activity against Gram-positive bacteria such as Staphylococcus pseudintermedius.

Polymyxin B Sulphate — Gram-Negative Bacterial Cover

Polymyxin B is a polypeptide antibiotic that disrupts the outer membrane of Gram-negative bacteria, causing cell death. This covers the bacterial spectrum not addressed by miconazole, particularly Gram-negative rods commonly found in secondary or chronic ear infections.

The Synergy Between Miconazole and Polymyxin B

In vitro studies have demonstrated a synergistic antimicrobial effect between miconazole nitrate and polymyxin B sulphate — the two antimicrobials in combination are more effective than either ingredient alone. This documented synergy is part of why Surolan consistently outperforms single-agent ear treatments in mixed infections.

Prednisolone Acetate — Anti-Inflammatory Relief

The corticosteroid component rapidly reduces the redness, swelling, pain and itch that make ear infections so distressing for pets. Without the anti-inflammatory component, even effective antimicrobial treatment would leave the pet uncomfortable for longer. Prednisolone acetate does not impair the antimicrobial activity of the other two ingredients at the concentration used.

Target Pathogens

Surolan is specifically indicated for otitis externa associated with:

• Malassezia pachydermatis — the most common yeast cause of otitis externa in dogs and cats; identified by the characteristic brown, waxy, coffee-ground appearance of ear discharge with a yeasty odour
• Staphylococcus pseudintermedius — the most common bacterial cause of canine otitis externa; can produce a more purulent, yellow-green discharge

The polymyxin B component additionally provides cover against Gram-negative bacteria commonly present in mixed or chronic infections.

⚠️ Critical Safety Check Before Every Use: Verify the Eardrum Is Intact

This is the most important safety rule for Surolan and all otic suspensions. Surolan must NEVER be used in an ear with a ruptured or perforated tympanic membrane (eardrum).

Using ear drops containing polymyxin B in an ear with a ruptured eardrum allows the medication to contact the middle and inner ear structures directly, which can cause permanent ototoxicity — irreversible damage to the hearing and balance structures. Cases of deafness following use of otic polymyxin B preparations with perforated eardrums have been reported.

A perforated eardrum can occur from:

• Severe or untreated ear infections
• Trauma to the ear
• Cotton buds or inappropriate objects inserted into the ear canal

Signs that may suggest a perforated eardrum include head tilt, loss of balance, unusual eye movements, or apparent deafness. If you are unsure whether the eardrum is intact, have a veterinarian examine the ear with an otoscope before using Surolan or any otic medication.

Dosage and Application

For otitis externa in dogs and cats:

Step-by-Step Application

1. Clean the ear canal first. Gently clean the external ear canal and remove any discharge, wax or debris. Dry the ear canal thoroughly. This is essential — debris prevents the medication from contacting the ear canal wall.
2. Confirm the eardrum is intact before the first treatment. Have your vet check this if unsure.
3. Shake the bottle well before each use. Surolan is a suspension that settles on standing.
4. Instil 5 drops of Surolan into the affected ear canal.
5. Massage the base of the ear gently for 30–60 seconds after instillation. This distributes the suspension throughout the ear canal and ensures contact with the canal walls.
6. Repeat in the other ear if both are affected.
7. Apply twice daily for 7 consecutive days. Do not stop early even if the ear appears better — incomplete treatment risks relapse and resistance.
8. Avoid touching the bottle tip to the ear to prevent contamination of the suspension.

Dosage Summary

A 15ml bottle provides sufficient suspension for one ear for a full 7-day course. If both ears are affected, a second bottle or a larger volume may be required depending on exact drop sizes.

Contraindications

• Ruptured or perforated tympanic membrane (eardrum) — absolute contraindication
• Known hypersensitivity to miconazole nitrate, polymyxin B sulphate, prednisolone acetate, or any excipient
• Do not use concurrently with other drugs known to cause ototoxicity, particularly aminoglycoside antibiotics (e.g. gentamicin, neomycin, tobramycin) by any route

Precautions

• Long-term use beyond 7 days: Extended use of topical otic corticosteroids has been associated with adrenocortical suppression and iatrogenic hypoadrenocorticism (Addison’s-like disease) in dogs. Use only for the prescribed 7-day course. If a repeat course is needed, consult your veterinarian.
• Breeding, pregnant, or lactating animals: The safety of Surolan has not been established in these groups. Use only on veterinary advice.
• Hearing monitoring: If any reduction in hearing or change in balance is observed during treatment, discontinue immediately and contact your veterinarian.
• Do not use other ear medications concurrently unless specifically directed by your veterinarian.

Side Effects

• Local reactions: Mild irritation, discomfort, or head shaking after administration — usually transient
• Hearing reduction: Temporary hearing reduction was reported in some dogs in clinical trials; this resolved in most cases. Permanent deafness has been reported in foreign market post-approval experience.
• Skin reactions: Red pustules on the pinna (ear flap) have been reported rarely
• Systemic corticosteroid effects: With prolonged or repeated courses beyond the recommended duration, systemic steroid effects can occur

Storage

• Store below 25°C (77°F)
• Do not freeze
• Keep in original packaging, out of reach of children and pets
• For otic (ear) use only — do not administer orally or by any other route

Surolan vs Easotic vs Otomax — Which Ear Drop Is Right?

All three are combination ear drops containing an antifungal, antibiotic, and corticosteroid. The key differences:

For a full clinical comparison of all three products, see our guide: Dog Ear Infections: How Easotic Works, How to Use It & How It Compares to Otomax and Surolan

Frequently Asked Questions

How many drops of Surolan per ear?

5 drops per affected ear, twice daily, for 7 consecutive days. Always shake the bottle well before counting drops, as Surolan is a suspension that settles. Hold the bottle vertically and count carefully — the suspension is thicker than water and drops may not fall as fast as aqueous solutions.

Can Surolan be used in cats?

Yes — in the international formulation Surolan is indicated for both dogs and cats. The same dose applies: 5 drops per affected ear, twice daily, for 7 days. Ensure the eardrum is intact before use in any species.

What happens if my dog’s eardrum is ruptured and I use Surolan?

Using Surolan (or any otic suspension containing polymyxin B) with a perforated eardrum is dangerous. The medication can contact middle and inner ear structures directly, potentially causing permanent damage to hearing and balance. If you are in any doubt about eardrum integrity, have a vet examine the ear with an otoscope before beginning treatment.

How quickly does Surolan work?

Most owners notice improvement in itch, head shaking, and discomfort within 24–48 hours of starting treatment. However, the full 7-day course must always be completed — stopping early when symptoms improve risks relapse and the development of resistance in the remaining bacteria or yeast.

Can Surolan be used with other ear medications?

Do not use other ear medications concurrently with Surolan unless specifically directed by your veterinarian. Particularly avoid aminoglycoside antibiotics (gentamicin, neomycin, tobramycin) given by any route at the same time — combined ototoxicity risk.

Do I need to clean my dog’s ears before applying Surolan?

Yes. Clean and dry the ear canal before starting treatment, and before each dose if significant discharge is present. A clean ear canal allows Surolan to contact the canal walls effectively. Use a veterinary ear cleaner recommended by your vet, and allow the ear to dry before applying Surolan.

Also available: Easotic Ear Drops 10ml (Gentamicin + Miconazole + HCA) | Marbogen Complex Ear Drops 10ml