How does a dog's ear get affected?
The dog's ear canal has a vertical and a horizontal component. This predisposes the dog to ear infections as debris must work its way upward rather than straight out.
Disease of the ear usually stems from over-production of wax as occurs in response to irritation. Allergic skin disease affecting the ears is one possible cause (especially in recurring cases); other causes of ear infections include ear mites, foreign bodies (such as grass awns or fox tails), or hair growth deep in the canal (common in poodles and schnauzers especially). The moisture of the wax promotes bacterial growth and infection. Soon wax in ears is joined by pus.
One thing of concern in dogs that are professionally groomed is the practice of plucking the hairs out of the dog's ear. The serum which then comes out of their pores is an excellent breeding ground for bacteria, which is a common cause of ear infection. Vets generally don't recommend you allow your dog's ears to be plucked unless their is a good medical reason to do so. An example of a good medical reason is if there is a large mat of hair that is blocking air flow.
If the mats of hair are in the ear canal, they should be removed by a vet only. If they're not, first soak the hair in a coat conditioner for a few minutes to soften it. Then, with your fingers, separate as much of the mat as possible.
You may be able to untangle the rest of the mat with a comb, but more likely you'll need scissors or a mat splitter. Be very careful if you're using scissors. Using a comb, position it under the mat to protect the skin. Hold the scissors at right angles to the comb, and cut into the matted fur in narrow strips. Very gently, tease the mat out, and then comb out any snarls that are left. Regular grooming, with the right tools, will avoid mats forming in the first place.
Symptoms
Dogs show discomfort around their ears by scratching, rubbing their ears on the floor or furniture, or by shaking the head. If the infection reaches the middle ear, affected animals may have a head tilt, a lack of balance, and unusual eye movements.
Infections - Aural Hematoma
When a dog with uncomfortable ears shakes and scratches vigorously, a blood vessel in the ear flap may rupture. This leads to bleeding into the tissues of the pinna . The usual recommendation is to have the blood clots removed and the ear bandaged and cleaned under anesthesia. If the hematoma is not so big as to occlude the ear canal (thus preventing medication), the option to forgo surgery exists; but without surgery, the ear may scar down into an abnormal appearance.
Treatment
- Step 1
Most ear infections are cleared up simply with professional cleaning followed by medication at home. If only mild debris is present in the ear canals, simple disinfection and washing of the ear is adequate; however, in most cases, a full ear flush is needed to even examine the ear drum. For patient comfort, sedation is recommend for this procedure as the ears are sore and the instruments can be damaging if the pet jumps at the wrong time.
Some dogs have chronic ear problems (the infection is not controlled by general medication or returns when general medication is discontinued). In these cases, the ear discharge should be cultured so that the precise organism can be pinpointed and treated specifically. Regular treatment at home with disinfecting ear washes should become part of the pet's grooming routine.
Further testing may be in order to determine why the infection continues to recur. Allergy is the most common reason for recurrent ear problems.
Depending on the severity of the problem, the vertical canal may need to be opened surgically. This enables debris to be removed more effectively. This is done to prevent severe scarring after prolonged specific medical therapy has been ineffective.
If the canal becomes so scarred that it is practically closed, "ablation" may be the final option. In this surgical procedure the entire ear canal is removed and healthy tissue is allowed to grow in. These procedures are "last resorts" after severe infection has made effective medical treatment impossible. A specialist is called in for these cases and, although surgery is expensive, dogs with chronic severe otitis usually require no further ear treatment for the rest of their lives.
Some important information on Pseudomonas infection:
Pseudomonas aeruginosa is a very special species of bacteria; it is resistant to almost every possible antibiotic. It is common for ear infections to be recurrent and in time, many antibiotics have been used. The unfortunate tendency is for most bacteria to be killed off, leaving infection with the very resistant and practically immortal (not to mention especially smelly) Pseudomonas.
If one if lucky, a culture of the ear discharge will reveal that the Pseudomonas is still sensitive to oral quinolone antibiotics such as enrofloxacin or orbifloxacin. It should be noted that especially high doses of this type of antibiotic are needed to treat Pseudomonas in the ear and that inadequate dosing will just make Pseudomonas even more resistant. In other words, Pseudomonas must be treated definitively from the moment it is diagnosed; once it becomes resistant to oral therapy, treatment becomes vastly more difficult.
Oral therapy is generally combined with some kind of topical treatment of the ear. Fortunately there are several concoctions that should be useful though some your vet must mix him/herself.
Other helpful medicines
- Silvadene/silver sulfadiazine
This product is manufactured as a wound creme and is especially helpful in hastening the healing of damaged external tissues. It also has activity against several bacteria including Pseudomonas. The creme can be prepared in water for an easier ear administration.
EDTA is a binder of metals which are important to the bacterial cell wall. Tris is used to buffer the EDTA to a pH that is not irritating to the ear and to maximize the anti-bacterial effect.
It would be unusual for a Pseudomonas species to be resistant to absolutely everything. While there may not be an oral treatment available, sometimes an owner may be taught to give injectable treatments. These are often expensive, however. These same medications can also be mixed up for topical use; many are already available as commercially prepared solutions.
