Ear infections in dogs are common and most dogs suffer from this painful condition sometime in their life. Scratching and rubbing at the ear(s) and head shaking are common signs. You may also notice an abnormal odor from the ear or see redness or swelling. Most ear infections in adults are caused by bacteria and yeast, though ear mites are a common cause in puppies. Youri veternarian will take a sample from the affected ear(s) and examine it under the microscope to help identify what microorganisms are present.
Causes of Ear Infections in Dogs
The inside of a dog’s ear begins with the vertical canal. The canal takes a turn and becomes the horizontal canal.
Next is the ear drum (tympanic membrane) followed by the middle and inner ear. Ear infections often start in the external ear canal, which includes both the vertical and horizontal canals. The lining of the canal produces oil and wax. When oil, wax, hair and other debris build up in the ear canal, it becomes a feeding ground for yeast and bacteria. Ear infections occur when excess bacteria and/or yeast grows in the ear canal. The external ear canal becomes inflamed (called otitis externa).
Some dogs secrete more earwax and oil than others. Some have too much hair inside the ears. These dogs are more prone to develop ear infections. In addition, dogs with allergies are also more likely to develop ear infections, as inflammation in the ears occurs secondary to allergies. Certain dog breeds, such as Basset Hounds and Cocker Spaniels are especially susceptible to ear infections.
Signs of Ear Infections in Dogs
Dogs with ear infections may have one or more of the following signs:
- Shaking head frequently
- Scratching at ears
- Odor from ears
- Excess debris in ears and/or discharge from ears
- Red, irritated ears (sometimes painful)
- Scabs and/or hair loss around ears (from scratching)
- Head tilt
How Ear Infections are Diagnosed in Dogs
You should bring your dog to the veterinarian at the first sign of an ear infection.
Typically, the vet or vet tech will use a swab to obtain a sample of the ear debris/discharge. The sample will be examined under a microscope to determine if there is yeast or bacteria present. This process is often called an ear cytology and it is an important diagnostic tool. The presence of yeast or bacteria (or both) confirms an ear infection diagnosis. Dogs with yeast ear infections often have dark brown or black debris in the ears. Dogs with bacterial ear infections may have yellow-brown debris or even greenish pus coming from the ears. However, without microscopic evidence, one cannot be certain of the type of ear infection present.
Once an ear infection has been diagnosed, your vet will discuss the proper treatment and ways to prevent recurrence. In many cases, your vet will clean your dog’s ears and send you home with ear medication to apply one to three times daily. You may also be sent with ear cleaner or ear flush and shown how to clean your dog’s ears regularly. It is very important to comply with your vet’s recommendations when it comes to managing ear infections. Otherwise, serious and potentially irreversible complications may develop. Next, learn how to treat an ear infection and prevent future ear infections.