How to help pet owners manage ear disease

Ear disease is incredibly common, not just in dogs, but also in rabbits and less frequently cats. Ear disorders are identified in 8% of dogs seen by primary care vets¹, although the American Kennel Club estimates that they affect up to 20% of dogs.² While most cases will require veterinary attention, appropriate cleaning before, during and after treatment plays a significant role. As an SQP/RAMA, you’re ideally placed to talk owners through the ins and outs of ear cleaning.

Why is ear disease a problem?

If you’ve ever had earache, you’ll be aware of how painful a sore ear can be. While acute ear infections are often picked up by owners, more chronic ear problems can be overlooked as pets struggle to show more chronic, dull pain.

If acute infections are left untreated, or treated inappropriately, more severe infections can develop. In some cases, infection can spread from the outer to the middle ear, causing neurological symptoms. Owners using previously prescribed antibiotic drops, often intermittently, to manage ear disease should be strongly discouraged, as antimicrobial resistant infections can be very difficult to treat.

Recurrent ear infections and chronic ear inflammation – up to 70% of which is linked to allergies³ – can cause permanent scarring and thickening of the tissues surrounding the ear canal. This narrows the canal, reducing air flow and increasing the likelihood of further infections in a vicious cycle. In severe cases, dogs may require a TECA (total ear canal ablation surgery), in which the entirety of the ear canal is removed.

How can owners recognise ear disease?

Owners usually recognise the signs of acute ear disease in cats and dogs – including head shaking, pawing at the ears, swelling or redness of the pinna, malodour and excessive discharge, often of an abnormal colour or consistency. However, in chronic, less severe cases (e.g. allergic patients) owners may perceive a low level of head shaking or discomfort to be normal for their pet. It is important they are aware that these “normal” actions are a sign of pain.

In rabbits, symptoms are less obvious – they don’t usually shake their head or scratch. Although painful, it can be hard to spot as rabbits hide their pain very successfully. Check for a swelling at the base of the ear where wax has built up, or neurological symptoms like a head tilt or facial asymmetry. Ear disease is much more common in lop-eared rabbits, so owners should be on the lookout in these breeds.

Common conditions

Otitis externa

Bacterial otitis externa (inflammation of the external ear canal) is the most common ear condition seen in dogs. While it can occur sporadically, for example after water has entered the ear, it’s often a recurrent issue linked to underlying allergies or other predisposing factors like increased wax production or droopy ears³ Basset Hounds, Shar Peis, Labradoodles, Beagles and Golden Retrievers are most commonly affected.

Topical antibiotic drops are usually required for treatment – but cleaning is hugely important for cases with excessive wax or pus production. In the very early stages of infection, consistent cleaning with a safe product may be sufficient for resolution.

In some cases of otitis – especially severe or recurrent cases – the eardrum (tympanic membrane) may rupture. In these cases, ear drops and cleaners can cause toxicity to the middle ear and neurological symptoms. Some very gentle cleaners may still be recommended, but owners should be warned of this risk if a vet hasn’t recently examined the ears and recommended cleaning.

Yeast infections

Typically caused by an overgrowth of Malassezia pachydermatitis, yeast infections of dogs’ paws and ears are common. They’re often associated with allergic skin disease as yeast thrives in warm, moist environments, but they can occur on their own or alongside bacterial infections. These infections are associated with a characteristic cheesy odour and variable inflammation, with mostly pale to dark brown waxy discharge.

Yeast infections can often be controlled by regular cleaning – drying products designed to clear excessive wax are best. More severe cases require prescription treatments. It’s vital for owners to try to control the underlying cause, or repeated infections are likely. Weekly maintenance ear cleaning can help to prevent this.

Allergies

Allergies – to environmental pollens, dust mites and other irritants or to specific foods – commonly cause inflammation of the ear canal. This is usually relatively mild with minimal discharge – but the swelling and increased blood flow to the ear canal promote secondary infections. All owners with dogs that suffer from recurrent ear infections should discuss underlying causes with their vet; it’s not uncommon for allergic dogs to show few or even no symptoms other than recurrent ear infections.

Routine ear cleaning can help to flush out pollen and irritants and maintain a healthy ear canal that’s less hospitable to infectious agents – a gentle, non-irritating cleaner should be used 1-2 times weekly.

Foreign bodies

This is one situation where cleaning isn’t a priority – if a pet is acutely distressed and in the space of a few hours starts to intensely shake their head and paw at an ear, a foreign body is a distinct possibility. Grass seeds commonly become trapped in the ear canal in summer and can cause severe damage if not removed quickly, so pets with these symptoms should be seen urgently by a vet.

Ear mites

While ear mites (Otodectes cynotis) are occasionally seen in dogs, in cats they cause 50-80% of ear infections.⁴ Pets with ear mites usually present with intense itching and relatively dry, dark ear wax.

In rabbits, the mite Psoroptes cuniculi is usually responsible. It can affect the ears but also skin on the rest of the body, causing itching, crusts and hair loss.

Luckily, ear mites are usually fairly easily treated with appropriate parasiticides – ear cleaning isn’t strictly necessary in most cases, though those with more wax may benefit from it. While most suitable products are prescription only, ear mites in rabbits may be treated using an over-the-counter topical ivermectin spot-on; typical products often require 3 applications at 14-day intervals. All in-contact rabbits must be treated as the mites are contagious.

Other ear conditions

Ear disease is a complex topic with many overlapping conditions. For any pet with moderate to severe or persistent symptoms of ear disease, or other abnormalities like masses or neurological symptoms, veterinary attention should be recommended.

The role of ear cleaning – when is it recommended?

How does cleaning help?

Clearing excess discharge and wax from the ears increases air flow, helps to reduce the amount of infectious material present, facilitates better visualisation by vets and can allow antimicrobials and antifungals to better penetrate the ear.

What to look for in ear cleaners

Beneficial ear cleaning ingredients include:

• Squalene – useful in cerumenolytic cleaners to clear thick, waxy discharge and safe for most ears.
• Propylene glycol, butylene glycol – dissolves wax, cerumenolytic.
• Tris-EDTA – enhances the effect of antibiotics and has antimicrobial properties. Gentle and safe for use in most ears. More effective for pus and watery discharge. Can help to disrupt biofilms in severe infections.
• Chlorhexidine – this can cause toxicity if the eardrum is ruptured, although a low concentration is relatively safe. Chlorhexidine is a disinfectant and can help to dry the ear.
• Salicylic & lactic acid – antibacterial.
• Acetic & boric acid – antibacterial and antifungal, good for yeast infections but may sting in very sore ears.

Which cleaner to use – and how often – depends on the situation. First, has a vet assessed the pet and identified an intact tympanic membrane? If the eardrum hasn’t been assessed, it’s best to stick to very gentle cleaners with ingredients like squalene and tris-EDTA.  Secondly, what type of infection is present?

When to use ear cleaners

In sore, irritated ears with significant discharge, cleaning is often recommended daily. In mild infections, thorough daily cleaning may result in resolution.

For aqueous discharge and pus – water-based cleaners including ingredients like tris-EDTA are most useful. Tris-EDTA can also enhance the action of antibiotic ear drops – but the cleaner must be used at least 30 minutes before any drops are applied.

For waxy discharge – ingredients like squalene and propylene glycol can be helpful to loosen thick or dry wax, while non-irritating surfactants and detergents can help to remove greasy material from the ear.

If a yeast infection is suspected, antifungal ingredients like boric and acetic acid are valuable, especially for long-term maintenance – however these can sting in sore, inflamed ears, and if the eardrum may be ruptured it’s best to use non-ototoxic ingredients like squalene.

For maintenance – once the infection is resolved, maintenance cleaning may be recommended for pets with chronic or recurrent ear issues. Cleaning once or twice a week can reduce the occurrence of flare-ups. For other pets, cleaning may be recommended after a suspected trigger, like grooming or swimming. It can make the ear a less hospitable environment for infectious agents and help to flush out pollen and other irritants.

A good maintenance cleaner is typically an all-round product containing antibacterial and antifungal agents as well as ingredients to dissolve and remove excess wax. Cleaners containing acids and antibacterial agents like chlorhexidine are often best and are better tolerated when the ear is less sore.

For rabbits – in normal, healthy rabbits ear cleaning is not required. However, some rabbits – especially lop-eared breeds – are prone to wax build-up. Regular cleaning with a rabbit-safe product may be beneficial in these cases, once a month or more frequently if needed.

When is ear cleaning not recommended?

Any case of moderate to severe ear disease should be assessed by a vet before cleaning is recommended – and certainly before any potentially toxic cleaning ingredients are used. This isn’t always visible externally, so if a dog seems to be in a lot of pain when ear cleaning is attempted, owners should see a vet before trying to continue. Severe cases may require sedation or anaesthesia for ear cleaning – and persisting with attempts to clean very sore ears when the patient is conscious can cause severe pain and subsequent reactivity.

Symptoms with acute onset which may indicate a foreign body should be seen urgently, and owners of dogs with recurrent ear infections should prioritise early veterinary assessment as they are at increased risk of resistant infections and ruptured eardrums.

Owners should also avoid cleaning their pet’s ears shortly before a vet appointment, as the fluid can make examination more difficult and prevent samples being taken.

How should owners clean pets’ ears?

• Remind owners that the ear canal runs horizontally then vertically – so placing the nozzle of cleaning products vertically into the ear canal should not cause trauma. If the ear is too sore for this, owners should make sure they fill the ear canal with cleaner from the outside.
• Apply ear cleaner generously – fill the ear canal and hold the pet’s head in a neutral position while gently massaging the base of the ear for 30-60 seconds.
• Wipe out the excess with cotton wool – if significant discharge is visible, this process can be repeated.
• If the inner aspect of the pinna is dirty, this should also be cleaned.
• Allow the pet to shake out the excess cleaner.
• If applying topical ear drops, leave 30 minutes after cleaning before applying them.

Finger wipes and similar products have become popular but their efficacy is limited as they do not clean the ear canal itself.

References

1. O’Neill, D.G., James, H., Brodbelt, D.C. et al. Prevalence of commonly diagnosed disorders in UK dogs under primary veterinary care: results and applications. BMC Vet Res 17, 69 (2021). https://doi.org/10.1186/s12917-021-02775-3
2. Elizabeth Racine, D. (2023, July 12). Dog ear infections: Symptoms, causes, treatment, and prevention. American Kennel Club. https://www.akc.org/expert-advice/health/dog-ear-infections/ Paterson S, Matyskiewicz W. A study to evaluate the primary causes associated with Pseudomonas otitis in 60 dogs. J Small Anim Pract. 2018;59(4):238–242.
3. O’Neill, D.G., Volk, A.V., Soares, T. et al. Frequency and predisposing factors for canine otitis externa in the UK – a primary veterinary care epidemiological view. Canine Genet Epidemiol 8, 7 (2021). https://doi.org/10.1186/s40575-021-00106-1
4. Yang, C., & Huang, H. P. (2016). Evidence-based veterinary dermatology: a review of published studies of treatments for Otodectes cynotis (ear mite) infestation in cats. Veterinary dermatology, 27(4), 221–e56. https://doi.org/10.1111/vde.12340