Ferrets produce a lot of reddish brown ear wax normally, and when they are infested with ear mites this will be in larger quantities and will be dark red. Unlike cats, ferrets rarely scratch or shake their heads even when their ears are full of wax or severely infested with mites. You will have to inspect the ears to know when they need cleaning. Ordinarily, ferrets will not require ear cleaning unless they have mites, although some older hobs secrete a great deal of wax that builds up both on the skin and inside the ears.
Occasionally ferrets get ear infections. This can result from the following conditions:
secondary to the damage done by ear mites,
after exposure to another animal with an ear infection, or
after a bath that has allowed water to get into the ear.
Ferrets with ear infections will both scratch and shake their heads, and the discharge will be brown, yellow, or green pus that may have a bad odor.
Cleaning the ears
Ferrets have very small ear canals. There is little value in putting medication on a thick layer of discharge. Do not put cotton-tipped applicators into the ear canal to remove wax: it will just be pushed further down, and may injure the eardrum. Your veterinarian can dispense an ear cleaning solution. After putting a few drops of this solution into the ear canal, massage the area below the external ear to soften and loosen material far down in the canal, and bring it up to the surface. A cotton-tipped swab can be used to clean this off the outer part of the ear. Repeat as often as necessary to get the ear canal very clean before using any medication.
Ferrets will not allow you to do anything to their ears without firm restraint. To properly clean and medicate ears, the ferret may be restrained by "scruffing," or taking a firm hold on the loose skin of the ferret's nape of the neck and gathering it into a bunch. It is easiest if one person scruffs the ferret and someone else treats the ears.
As soon as you release the ferret after putting anything into its ear, the ferret will run around and shake its head. For the sake of your furniture and interior decoration, clean and treat the ears in a room with washable surfaces, and hang your suede jacket in the closet before beginning.
Treating for ear mites
If your ferret has ear mites, after cleaning the ear thoroughly, drop the ear mite medication into the ear canal: a large quantity is not necessary, but it should go well down into the canal, not sit on the surface of the external ear. Treatment must be repeated several times at regular intervals to kill all the mites. The length of the intervals will depend on the specific medication. If there are either cats or dogs in the same area as the ferret, treat all of them for mites or the ferret will become reinfested very soon.
Ear infections
If your ferret has red, sore-looking ears, it probably has a bacterial or yeast infection and should be treated by a veterinarian. Ear infections can take a long time to completely clear up, especially if they are neglected or incorrectly treated to begin with. Sometimes a bacterial culture of the ear is required to decide what type of antibiotic will work best.
Take the ferret to a veterinarian if you have treated it for ear mites and the ears are still red and sore, or if there is a constant discharge that looks like pus instead of wax.