ear problems in dogs
Straightforward ear infections are quite rare.
Ear mites are also quite rare.
Most cases of ear disease occur because of allergies which create inflammation which then leads on to the development of an infection, overproduction of wax in the ear, floppy or hairy ears which stop the passage of air into the ear canal, or foreign bodies which are typically spiky grass 'awns' (seeds), getting into the ear canal or because of other kinds of trauma to the ear.
In all cases it is important to examine the ear thoroughly, mainly to check that there is no foreign body present. If there is too much wax or exudate to see down the ear canal or if your dog is uncooperative or if the ear is too uncomfortable to examine the ear fully it may be necessary to clean and examine the ear under sedation (or general anaesthesia in more painful cases).
It is also very important to be able to check whether the ear drum is intact as a damaged ear drum may allow infection to spread into the inner ear, which becomes a very much more serious situation and can even become fatal.
In most cases we also need to know what kind of bacteria or other organisms are present. In a high proportion of cases the organisms are mainly a yeast called Malassezia but there may be a variety of bacteria also. In cases where there is a mucky or smelly discharge there may be more serious infection and we may need to send off a swab to our lab to find out which antibiotics are appropriate for treatment.
In all cases a relatively long period of treatment is needed because the bugs causing the trouble produce spores or have other resistant stages so that treatment kills off the active organisms quite quickly but if you stop treatment too soon the spores regenerate and you have a new infection back again.