Introduction
If your dog has a red, sore, itchy ear, then you might be wondering what is causing it? An ear infection? Ear mites? Something else entirely?
A sore ear is always a reason to book an appointment with a veterinarian, but if you are curious to know what your vet might find, then read on!
What Are Ear Infections?
An ear infection – also known as “otitis externa” – is one of the most common reasons for a dog to need to see a veterinarian.
Ear infections are usually caused by bacteria or yeast growing in the skin that lines the ear. There are normally a few of these bacteria and yeast living on the skin, but they do not cause any harm – indeed, it is healthy for dogs to have a mix of different microorganisms growing on their skin.
However, if something upsets the normal balance within the ear, then these bacteria and yeast start growing much more quickly than they normally would. Occasionally we can also see a new bacterium (which does not usually live in the ear) getting into the ear and growing rapidly.
This growth of bacteria and yeast damages the inside of the ear canal and causes the symptoms of an ear infection.
Symptoms of Ear Infections
- An itchy ear (occasionally both ears)
- Redness around the ear
- Discharge from the ear – usually thick and sticky
- Pain when the ear is touched.
What Are Ear Mites?
Ear mites (Otodectes cynotis) are small parasites that live in the ears of dogs, cats, rabbits, and ferrets. They live off the dead cells that are naturally shed by the skin that lines the inside of the ear. These mites are too small to be seen with the naked eye, but your veterinarian can see them under a microscope.
Some dogs will carry these mites without showing signs of irritation, but other dogs will be irritated by them. This irritation can lead to the symptoms of ear mites.
Symptoms of Ear Mites
- Itchy ears (usually both sides)
- Redness around the ear
- Discharge from the ear – usually yellow or brown, and crusty or waxy
- Pain when the ear is touched.
How do you tell the difference between ear infections and ear mites?
The symptoms of ear mites and ear infections are very similar, and in many cases, it is not possible to tell the difference between them without running further tests. However, there are some clues that we can look for to try and tell the difference:
- Ear mites usually affect both ears. Ear infections may affect just one ear or may affect both ears.
- The discharge in ear infections is usually thicker and stickier, whereas with ear mites it is drier and crusty or waxy. However, ear mites can also be the cause of an ear infection and so result in the infection producing a waxy discharge.
- Ear mites are contagious, meaning they can easily be passed to other pets in the household. However, not all pets with ear mites will show symptoms. Ear infections are usually not contagious, meaning that only one pet in the household will be affected.
It is important to try and work out what is causing your dog’s itchy ear, as the treatments for ear infections and ear mites can be different.
Diagnostic Testing
In order to tell the difference between ear mites and an ear infection, your veterinarian will need to take a sample of the discharge from your dog’s ear and look at it under a microscope. Ear mites can be seen directly in this way. If the sample is stained with special dyes, then your vet can also look to see if there are any bacteria or yeast present in the ear.
Your vet may also need to send a sample to a laboratory for culture. This allows them to grow and identify the specific bacteria or yeast that are causing the problem.
In some cases, dogs will have both ear mites and an ear infection.
Treating Ear Infections
Ear infections are usually treated with antibiotic ear drops, which often also contain antifungal medication (to treat any yeast) and steroids (to soothe the inflammation). Ear cleaning will usually be needed alongside this. This may be done during your appointment or you will be given instructions on how to clean the ears at home. Severe cases, where the eardrum is damaged, may need tablets (steroids and antibiotics) to resolve.
However, ear infections are often caused by some other illness, which weakens the skin of the ear and allows the overgrowth of bacteria and yeast to occur. These illnesses include:
- Seasonal allergies
- Hormone conditions (such as an under-active thyroid)
- A foreign object in the ear (such as a grass seed or awn).
In order to prevent the ear infection from returning, your vet will need to diagnose and treat the underlying health condition that is causing it.
Treating Ear Mites
Ear mites can be treated in a variety of different ways.
You may find home remedies available online, but these are rarely effective, and can sometimes end up causing more problems than they solve. Likewise, over-the-counter ear mite drops are often ineffective.
Your veterinarian can either give you prescription ear drops (similar to those used for ear infections), or a prescription mite tablet or spot-on to give to your dog. These are combination products that will also treat fleas, and sometimes ticks or roundworms, as well as the mites.
Examples include:
- Macrocyclic lactones such as selamectin
- Isoxazolines such as fluralaner
Some of these medications may be used off-label for the treatment of ear mites but have been shown to be very effective in scientific studies. Many are licensed to treat ear mites in other countries.
Conclusion
The symptoms of ear mites and ear infections can be very similar, and unless the ear mites spread to other pets, it can be difficult to tell them apart. However, it is important to make the distinction, as the treatment can be quite different. Your veterinarian can examine your dog and check for ear mites using a microscope, and prescribe you a safe and effective treatment that will get them back to their normal healthy selves.
