Ear Infections in Guinea Pigs

What Are Guinea Pig Ear Infections?

Ear infection, also called otitis, means inflammation of the ear. There are three possible types of ear infection in guinea pigs:

• External (otitis externa)

• Middle (otitis media)

• Inner (otitis interna)

External ear infections are rare in guinea pigs while middle and inner ear infections are more common.

The outer ear is the made up of the fleshy outer ear or pinna, the ear canal, and stops at the ear drum. The cartilage ear canal in guinea pigs is very long and has several turns making it difficult to see their ear drum externally. The middle ear contains boney ossicles used for sound transmission and is connected to the cavity behind the nose and mouth. The facial nerve is also located in the middle ear which helps to close the eye. The inner ear contains the two receptor organs which are used for hearing and balance.

Ear infections are not very common in guinea pigs. They are often secondary to pneumonia or another respiratory disease because bacteria can travel from the lungs/sinus cavity. If you suspect your guinea pig has an ear infection, call your veterinarian right away.

Symptoms of Guinea Pig Ear Infections

• Ear discharge/debris

• Swelling and redness of the ear pinna

• Head tilt

• Circling or leaning to one side

• Rolling

• Ataxia or stumbling while walking

• Itching or excessive flicking of the ears or head

• Outer ear drooping

• Anorexia

• Diarrhea or decrease in fecal output

• Nasal or eye discharge

• Involuntary movement of eyes from side to side, up and down, or in circular motions

Causes of Guinea Pig Ear Infections

Ear infections in guinea pigs can be caused by an overgrowth of yeast such as Malassezia or Candida. Bacterial infections are often secondary to pneumonia or upper respiratory sinus infections from Bordetella or Streptococcus.

The bacteria travel via the auditory tube to the middle and inner ear causing infection. Sometimes ear infections can occur in just one ear from foreign material becoming stuck like a piece of grass, from a tumor, or from injury to the ears. The ears can also become injured from bites or scratches from another guinea pig. Guinea pigs that do not have a strong immune system due to stress or Vitamin C deficiency can make them more susceptible to infections.

How Veterinarians Diagnose Ear Infections in Guinea Pigs

Your veterinarian will take a thorough history of signs and symptoms. After that, they will perform a physical and ear examination. Some tests that your veterinarian might perform include:

• Cytology involves taking a swab to collect debris from the ear, staining that debris on a slide and then examining the contents under a microscope to look for bacteria, yeast, ectoparasites and any cells

• Culture/sensitivity testing of the debris is used to grow and identify any bacteria causing the infection and then test which antibiotics would work to eliminate the infection.

• Blood tests to look for any systemic signs of infection or any other underlying diseases/conditions that could be contributing to the ear infection

• X-rays, CT scan, and MRI can be performed to get images of the inner and middle ear to evaluate for disease.

Treatment of Guinea Pig Ear Infections

Topical antibiotic ear drops can be prescribed. If there is any damage to the facial nerve then topical eye drops are prescribed to keep the eye lubricated.

In addition to topical, systemic antibiotics for respiratory disease or middle/inner ear infections can also be prescribed. If your guinea pig is not eating well, syringe feedings and vitamin C supplementation are often recommended. Pain medications or anti-inflammatories to keep your guinea pig comfortable also may be recommended. Meclizine can be prescribed to help decrease involuntary movement of eyes.

It is important to finish out any antibiotics prescribed. Even though clinical signs may have improved, stopping antibiotics too soon can lead to the bacteria becoming resistant and the infection not fully cleared.

For persistent internal ear infections, surgical procedures can be performed to remove any debris in the middle ear.

Recovery and Management of Guinea Pig Ear Infections

External ear infections typically resolve with treatment in 2 weeks. Inner and middle ear infections can take weeks to months of therapy.

If external ear trauma was caused by a housemate, that animal should be separated from the affected guinea pig to prevent recurrence. It is also important to provide proper nutrition and vitamin C, and proper ventilation.

Guinea pigs have excellent hearing. If ear infection occurs in the middle or inner ear, it can cause deafness. Inner ear infections can also cause loss of balance. Internal and middle ear infections have a more guarded prognosis because they can take weeks to months to resolve, and sometimes facial nerve damage can be permanent. If the infection spreads to the brain causing seizures the prognosis becomes grave. Without proper treatment, ear infections can become a chronic problem in guinea pigs.