Antibiotics for Otitis Externa in Dogs

Otitis externa or external ear infections are easily developed by dogs. The ear canal has both a horizontal and a vertical component and therefore, foreign matter which enters the canal can be stuck in and easily cause an infection. Ear infections in dogs are usually produced by allergic skin diseases, ear mites, bacteria, foreign bodies that penetrate deep in the ear canal. The wax deposits in the ear favor the development of infections. Left untreated, ear infections can result in loss of equilibrium, eye problems or facial nerve paralysis. If neglected or treated improperly, ear infections might require surgery and ear resection. 

Antibiotics for Otitis Externa in Dogs

Antibiotics are usually recommended for treating bacterial ear infections in dogs. Generally, the treatment starts with a broad spectrum light antibiotic. It is very important that you respect the administration recommended by the veterinarian and that you complete the treatment even if the dog’s condition improves. If the treatment is interrupted before all bacteria are killed, they can develop resistance to that specific antibiotic. A stronger antibiotic will be necessary.

If the infection is recurrent, ear discharge will be tested so that the antibiotic prescribed should target the specific organism causing the infection.

The ear infection can have an underlying condition, such as allergies. The treatment plan should address the underlying condition as well.

Pathogens Causing Otitis Externa in Dogs

The most common method to classify bacteria is Gram-staining. This method divides bacteria into two main groups: Gram-positive and Gram-negative bacteria. Gram-negative bacteria are more resistant to antibiotics than Gram-positive bacteria.

Pseudomonas aeruginosa is a Gram-negative bacterium which causes otitis externa and is resistant to most antibiotics. Infections caused by it reoccur in time.

Repeated use of topical antibiotics as treatment of ear infections makes pseudomonas more resistant. The same problem occurs if medication is administered in a smaller dosage than needed.

Pseudomonas is treatable with oral administration of enrofloxacin, orbifloxacin, marbofloxicin or ciprofloxacin. These antibiotics have to be administered in high dosage and the treatment must be definitive. Otherwise, the bacteria may become resistant to this treatment as well.

Gram-positive pathogens such as staphylococci are easier to treat using topical antibiotics. Aminoglycosides are efficient against them. Aminoglycosides are modified sugars which act as antibiotics.

Prevention of Otitis Externa in Dogs

The best way to prevent ear infections is to keep the ears clean. Weekly cleaning of the ears is recommended. If your dog is prone to developing ear diseases or swims regularly, ear grooming should be performed more often.

Use ear cleaners to clean the dog’s ears. Make sure you do not use sharp objects when cleaning the ear canal, as this can hurt the do.

It is important to remove wax deposits from your dog’s ears. Wax creates the proper environment for ear infections to develop.

You should also cut excess hair in the ear area.

If you notice anything unusual or an unpleasant smell coming from your dog’s ear, contact your veterinarian.