What is Otitis Externa in Dogs?
Otitis externa is the inflammation of the outer ear and ear canal. It is the most common ear infection in dogs.
In otitis externa, the middle ear is not involved and the ear flaps (pinna) may or may not be involved.
Otitis externa can be acute – inflammation that occurs suddenly, or chronic – inflammation that has continued for weeks or months.
External ear infection can affect both the ears or one ear of the dog.
What are the Signs of Otitis Externa in Dogs?
The signs of otitis externa in dogs is identical to signs of ear infection in dogs discussed in the previous blog.
The signs of otitis externa in dogs include –
- Head shaking
- Strange smell from the ears
- Swelling
- Redness
- Ulceration
- Presence of excessive sticky substances on the ears
- Inflammation of the gland that produces earwax
What Causes Otitis Externa in Dogs?
The classification of the causes of otitis externa is divided into “causes” and “factors”. The causes of ear infection in dogs include diseases or infectious agents, while the factors contribute or promote the inflammation.
The causes of otitis externa in dogs is classified as primary, and secondary. There can be perpetuating factors and predisposing factors that increase the risk of dogs to develop the infection and inflammation in the first place.
What are the Primary causes of Otitis Externa in Dogs?
The primary causes of otitis externa in dogs –
- Allergy: Food or environmental allergies can inflame the ear canal, making it more prone to infections.
- Bacteria: Bacterial overgrowth in an inflamed or moist ear causes pain, discharge, and foul odour.
- Parasites: Ear mites cause intense itching, head shaking, and dark ear discharge, especially in puppies.
- Fungi: Fungal infections occur in warm, humid conditions and often accompany other ear problems.
- Yeast: Yeast thrives in moist ears, leading to chronic inflammation and a strong, musty smell.
- Viruses: Viral infections can damage ear tissues and allow secondary bacterial or yeast infections.
- Autoimmune diseases: Immune-mediated conditions cause chronic ear inflammation and recurrent infections.
- Hormonal disorders (hypothyroidism, hyperadrenocorticism): Conditions like hypothyroidism affect skin health, increasing the risk of ear infections.
- Foreign bodies: Grass seeds or debris in the ear cause sudden pain and inflammation.
- Moisture buildup: Trapped moisture after bathing or swimming promotes infection.
- Excessive cleaning: Over-cleaning irritates the ear canal and removes natural protection.
- Narrow ear canals: Poor airflow traps moisture and debris, increasing infection risk.
- Disorders of the glands in the ears: Abnormal wax production creates an environment for infection.
What are the Secondary Causes of Otitis Externa in Dogs?
Secondary causes of otitis externa in dogs create the inflammation in an already “abnormal” ear. These are commonly recurrent infections.
The secondary causes of otitis externa in dogs include –
- Reactions to medication
- Abrasions from scratching
- Immune suppression
Discuss allergy control with a Vetic vet to prevent chronic ear infections.
What are the Perpetuating Factors of Otitis Externa in Dogs?
The perpetuating factors are present due to ear inflammation and they can be quite severe in the chronic cases of canine otitis externa.
The perpetuating factors of canine otitis externa include –
- Epithelial changes
- Changes in the ear canal
- Damage or rupture of the eardrum (tympanum)
- Swelling (hyperplasia) of the gland(s)
- Middle ear disease (otitis media)
- Chronic thickening of the ear canal
Chronic inflammation can permanently alter the ear canal structure, making infections harder to treat.
Read more about Chronic Ear Infections in Dogs.
What are the Predisposing Factors of Otitis Externa in Dogs?
Predisposing factors make some dogs more susceptible to developing canine otitis externa. These include:
- The shape, size and hair density of their ears
- Environmental factors such as moisture (swimming)
- Primary otitis media or middle ear infection
- Obstruction in the ear or ear canal
- Systemic diseases
- Side effects of other treatments
How to Diagnose Otitis Externa in Dogs?
The diagnosis of canine otitis externa is ONLY made by the veterinarian based on the dog’s medical history, physical examination (otoscopy) and cytology.
Some breeds are more predisposed to otitis externa due to their allergy profiles, for example, Golden Retriever, Labrador Retriever, Poodle, German Shepherd, Cocker Spaniel and terrier breeds. Young dogs may be more commonly affected.
The clinical signs combined with complete physical examination contribute to the conclusive diagnosis of otitis externa in dogs.
Veterinarians use otoscopic examinations, ear swabs, and cytology for the diagnosis of canine otitis externa. It helps to identify whether the infection is bacterial, yeast-based, or mixed.
During the otoscopic examination, the dog can be sedated depending on the pain and discomfort they are experiencing. Sedation and treatment with corticosteroids can make the otoscopic examination less painful for your pet.
Cytologic evaluation involves taking samples from the ears using a swab and examining the sample on slides using advanced microscopy. It can help the veterinarian determine whether the sample has bacteria, fungi, yeast, parasites or other types of cells present in the infected ear.
In case, the veterinarian cannot get a clear view of the eardrum due to excess swelling and discharge, they can recommend an X-ray.
What’s the Treatment for Otitis Externa in Dogs?
The treatment of ear infection in dogs should ONLY be prescribed by a veterinarian. Treatment depends on the severity and underlying cause of infection. Most cases respond well to topical or oral medications when treated early.
Step 1: Gentle Ear Cleaning and Rinsing to Remove Debris
Veterinarians may prescribe medicated ear-cleaning solutions to remove wax, debris, and discharge safely. Ear cleaning and flushing may be prescribed for 2 to 3 days per week until the odour, swelling and discharge subside.
Deep ear flushing should only be done by a vet to prevent injury to the eardrum.
Step 2: Veterinary Consultation and Proper Medication
Most dogs will require pain management and medication for itching. Your veterinarian will recommend these medicines depending on your dog’s current health, weight and age.
Topical antibiotics and antimicrobial drops are the most commonly prescribed medicines. They are most effective in the treatment of otitis externa in dogs. Canine otitis treatment may include:
- Antibiotic ear drops for a dog
- Antifungal medications
- Corticosteroid drops to reduce inflammation
Oral antimicrobial medicines may also be recommended by the veterinarian. However, they are in no way replacements for the topical ear drops and ear cleanings.
Do not use antiseptic or antimicrobial powders on your dog’s ears. They can solidify with the discharge and worsen the irritation in their ear canals. Avoid over-cleaning or using cotton buds, as they can push debris deeper into the ear canal.
The duration of the otitis externa treatment depends upon how badly the ear(s) is affected and also the type of infection leading up to otitis externa.
Step 3: Regular Follow-Up Visits and Ongoing Monitoring
Follow-up visits ensure the infection has resolved completely, inflammation has reduced, and hearing is preserved.
Do not stop the canine otitis externa treatment once the ears begin to “look better”. Stopping treatment early can lead to recurrence. Speak to the vet once the condition of your dog’s ears begin to improve.
Get professional treatment for your pet’s ear infection at a nearby Vetic clinic.
How to Prevent Otitis Externa in Dogs?
According to experts around the globe, prevention is the best treatment for chronic ear infection! Consider these things to prevent ear infections in dogs:
- Avoid the food and environmental triggers of your dog’s allergy.
- Clean their ears at least weekly.
- Always dry their ears completely after baths and swims.
- Avoid moisture buildup
- Use only vet-approved ear cleaners
- Trim the extra hair around their ears if they trap water.
- Give them parasite preventives (spot-on, Bravecto or Simparica) at the correct intervals.
Visit the veterinarian for preventive check-up if your dog scratches their ears or you see nail marks on/in their ears. Schedule regular grooming and ear checks with Vetic.
What are the Complications of Untreated Otitis Externa?
If left untreated, otitis externa can progress to:
- Chronic ear infections
- Middle ear infection (otitis media)
- Permanent ear canal damage
- Hearing loss
- Persistent pain and behavioural changes
Frequently Asked Questions
1. What is Otitis Externa in dogs?
Otitis externa is inflammation of the outer ear canal, commonly caused by infections or allergies. While it often starts as mild irritation, it can become painful and chronic if left untreated.
2. What are the common signs of Otitis Externa in dogs?
Common signs of otitis externa in dogs are head shaking, redness, discharge, bad odor, and scratching. These early symptoms of otitis in dogs are easy to miss but addressing them promptly can prevent severe infection and pain.
3. What causes Otitis Externa in dogs?
Some common otitis externa causes are: allergies, bacteria, yeast, parasites, moisture, and foreign bodies. A veterinarian must identify the underlying cause to prevent recurrence.
4. How is Otitis Externa diagnosed in dogs?
Otitis externa diagnosis is done through otoscopic exams, ear swabs, and cytology by a veterinarian. Sedation may be used if the dog is in pain or the ear canal is severely swollen.
5. Can Otitis Externa in dogs be prevented?
Yes, otitis externa in dogs can be prevented with regular ear cleaning, moisture control, and preventive care.
6. How is Otitis Externa treated in dogs?
Otitis externa in dogs can be treated with vet-prescribed ear drops, oral medications, and proper cleaning. Canine otitis externa treatment should always be completed for the full duration prescribed by the veterinarian.
7. Why is it important to address the signs quickly?
Early treatment prevents pain, recurrence, and complications in dogs.
8. What are the potential complications if untreated?
If an ear infection is left untreated, it can lead to chronic infection, middle ear disease, and hearing loss.
9. Are certain dog breeds more prone?
Yes. Dogs with floppy ears, narrow ear canals, or underlying allergies are more prone. Commonly affected breeds include: Cocker Spaniels, Labrador and Golden Retrievers, Poodles, German Shepherds, and Bulldogs, and terrier breeds
10. How can I clean my dog’s ears safely?
To clean a dog’s ear safely, use vet-approved ear cleaners and avoid cotton buds. Improper ear cleaning can worsen inflammation and push debris deeper into the ear canal.
