Another article same subject here
surgery sometimes required for a permanent cure here.
Repeated ear infections occasionally due to hypothyroidism here.
My librarians sent me three excellent articles published on otitis in pets to let you read. The first, which covers common causes of this problem, you can read here. The second, covers treatment options. You can read that one here. The third, covers infections that have penetrated deeper into your pet's middle ear. Read that one here.
One of the most frequent problems veterinarians see in pets are inflammations and infections of the ear. It is the second most common reason that dogs are brought to veterinary hospitals and the seventh most common reason cats are. The medical term for this is otitis. The first sign of this problem is your pets shaking its head or pawing at its ear. Soon it may begin to tip it's head to the most bothersome side. With time, the condition often becomes quite painful.
There are four common reasons why pets have frequent bouts of otitis. The first three are due to how we have bred ear-shape over the years that dogs have become man’s best friend.
The first was the advent of pets with floppy ears. Floppy ears trap moisture and air within the ear canal and make it an ideal place for bacteria and yeast to grow. This results in infection and inflammation as bacteria and yeast proliferate . Cocker Spaniels, Setters, Basset hounds, Beagles and, Shar Peis commonly have this problem, but any breed or mutt with floppy ears is more susceptible than a pet with ears that stand erect.
The second most common cause of ear problems in dogs is their high prevalence of inherited skin allergies. When humans become allergic to things in our environment we suffer from nasal, and lung congestion as the body produces histamines. But in dogs, histamines cause itching and irritation. The ear is lined with very sensitive waxy skin, that also becomes itchy in allergic dogs. As a pet scratches and rubs at its ears it causes inflammation and the release of moist exudates that grow bacteria and molds. The result is an ear infection or otitis. Labrador retrievers, Setters, Cocker Spaniels, West Highland Terriers, Schnauzers and Wheaten Terriers come to mind when one thinks of this problem, but any breed or mutt is susceptible. Flea infestation will also cause generalized itching and allergies in some pets. So fleas can also lead to otitis. Allergic causes of otitis are much rarer in cats.
The third most common cause of ear problems in specific breeds of dogs is the presence of thick hair within the ear canal. For reasons unknown to me, certain breeds have been developed that have luxuriant hair growth within their ear canals. This hair traps debris, moisture and earwax within the ear canals, which again sets up condition for bacterial and fungal (yeast) growth. Breeds associated with this problem include Poodles, Maltese, Pekingese, Spaniels, Schnauzers, Lhasa Apsos and Shih Tzus. It is not a common cause in cats.
The fourth is the high incidence of ear mites in young puppies. Ear mites, Otodectes cynotis irritate the lining of your pet's ear canal. With time, this irritation leads to infection. By the time the pet is examined by your veterinarian, the ear mites may all be gone. But in many cases of otitis in younger pets, the initial problem was mites.
Ear mites are the leading cause of ear infections in cats. If mites are still present, they can be killed easily with a number of medications your veterinarian dispenses. If mites are not present in your cat and it is still subject to repeated ear problems, it should be tested for feline immunodeficiency virus and feline leukemia. If you have multiple cats, they all need to be treated.
In the Southern USA, veterinarians see quite a few ear problems in large breed dogs that are associated with swimming in swimming pools and stagnant fresh water.
Otitis is are also seen associated with abnormal ear wax formation. In some dogs, the normally oily wax is replaced with a cheesy coagulated material that builds up within the ear canal. Perhaps this is a genetic problem.
There is controversy as to the part hypothyroidism might play in leading to chronic otitis in some pets.
Overweight and obese pets are more susceptible to ear problems because the amount of air that can circulate within their ear canals is limited.
Whatever the cause of your dogs ear problems, there are some general guidelines that apply in all cases.
The first is to not give up hope. It is bothersome to you and painful to your pet, but otitis can be cured or at least controlled. It just takes persistence. The first thing to do is to attempt to eliminate the cause. If fleas are present, use one of the modern methods of flea control. If other allergies are suspected, try a hypoallergenic diet available through your veterinarian or one you prepare yourself. Use it for a minimum of 90 days before deciding if it is helpful.
Hair growing within the ear canals can be plucked out with forceps. This is not as painful to the dog as you might think. Blunt the ends of the forceps and polish them with a flame so they can not injure your pet's ears. A caring veterinarian or groomer should be able to supply you with a pair of hemostats (forceps) and instruct you in using them to remove the offending hair. A puff of talcum powder or starch will help you grip the hair.
Conditions within the ear can be change with medications to discourage the growth of bacteria and yeast. Most of these products make the ear canal more acid. Yeast and bacteria do not grow well in an acidic medium. I like formulas for ear washes that combine propylene glycol, boric and salicylic acid (citric acid might also be an option [ref]). The ear canal can be filled with this liquid and then vigorously massaged. When you finish, allow the dog to shake his head rigorously to sling out the wax and debris. Once a mild flare-up has subsided, treatment with only a few drops, done weekly, is usually sufficient to keep the problem under control. More serious head-shaking and pawing need your veterinarians attention and advice. Your vet has more powerful prescription ear products. Remember that dogs and cats that have had an incident of ear problems are at a higher risk of having them again. So you may want to continue weekly applications of these over-the-counter otic solutions indefinitely.
Veterinarians will often send you home with eardrops or a tube of ear ointment. These ointments generally contain antibiotics to kill bacteria, anti fungal compounds to kill yeast and corticosteroid to decrease inflammation and itching. All these medications bring fast relief. However, with continued use, new, antibiotic resistant bacteria emerge. Try not to obtain the same antibiotic formulation twice in a row. Alternate products to reduce the chances of resistant bacteria developing. Emerging resistance is why, whenever possible, I use non-antibiotic, bacteriostatic, ear washes rather than ear ointments and drops that contain antibiotics. Needlessly exposing potentially pathogenic bacteria that reside in your household to long term antibiotics can be a threat to all family members. (ref)
If and when medical treatment is not enough, there are two surgical procedures, which are very successful in curing ear problems or at least bringing long-term relief to your pet. If the middle and inner ears are still intact, the ear canal can be surgically shortened and bent downward to facilitate good drainage. This procedure is called a Zepp otoplasty. If the middle and/or inner ear is already involved a more radical surgery called ear canal ablation or or subtotal ablation is usually quite successful in bringing permanent relief to your pet. Read about that procedure here. The quality of life after these procedures is generally very good. It is so rewarding to me to see these pets finally free of pain. Read more about that surgical option here.