You might be suprised to find that much of your ferret's odor actually comes from it's ears. Sounds hard to believe, but it's true. Those tiny little ears can produce a large amount of odor. Cleaning your ferret's ears regularly will help rid them of this odor or at leastt keep it down to a bare minimum.
There are scent glands located right behind each ear, so that area will smell a bit musky to begin with. Dirty ears will increase the odor. How often the ears need to be cleaned will depend on the individual ferret. Some will only need their ears cleaned once every week or so, while others may need their ears cleaned several times a week. There are some ferrets who seem to have a never ending supply of wax and dirt in their ears! Excessive ear wax is not necessarily abnormal or a sign of a medical problem. That may just be the "normal" amount for that particular ferret. The color of your ferret's ear wax will tell you if there is a problem with the ears. Healthy ear wax is a reddish brown color. If the ear wax is black, red, or any other unusual color, a trip to a ferret knowledgeable vet is strongly advised. Black ear wax may have a "tarry" appearance. Also, any fluid draining from the ears will also need to be checked.
If it looks like your ferret has coffee grinds in it's ears, this could be an indication of ear mites, a very common problem in ferrets. If your ferret does have ear mites, you vet will prescribe something to alleviate the problem. Ear mites can be difficult to get rid of, so not every treatment will work. Also, if you are treating one ferret for ear mites, all the ferrets in the household should be treated at the same time. Ear mites are easily spread and treating for them can become a never ending cycle. When left without treatment, ear mites can lead to infection and damage to the inner ear including deafness and other permanent problems. Besides the "coffee grind" appearance of the ears, there are other signs that will tell you that your ferret may have ear mites. Rubbing the affected ear(s) against the floor or other surfaces, head tilting(this can also be a symptom of other conditions), persistent head shaking, constant scratching of the affected ear(s)(there may also be scabs on the back of the ears due to the persistent scratching), and obvious signs of pain or discomfort during routine ear cleaning such as vocalizing(crying, whining), trying to pull away more than usual and trying to bite are just a few of these signs. These can be signs of other conditions, so it's best to bring them to the attention of your vet.
You will need the following items to clean your ferret's ears: q-tips(cotton swabs), ferret-safe(or kitten-safe) ear cleaner, and a lickable treat such as Ferretone, Linatone, Ferretvite, or Nutrical. It always helps to have another person there to assist you, but you can do it by yourself with a little practice. Start by scruffing the ferret(grasping it by the loose skin on the back of the neck). Scruffing helps keep your ferret's head still. The head must be kept as still as possible. If the ferret jerks or moves it's head suddenly during cleaning, it can cause injury or damage to the inner ear and/or ear drum. Remember to always keep your ferrets bottom half supported by resting their hind end on your leg or another surface. Holding your ferret in a scruff without support can put too much strain on the spinal cord and can possibly cause injuries. While scruffing your ferret with one hand, use the other to clean each ear thoroughly. Most(if not all) ferrets do not enjoy having their ears cleaned and will not hold still. There are 2 methods you can try.
One is while holding the ferret in a scruff, take the thumb of your "scruffing" hand and hold the ear flap flat against the ferret's head; this makes it easier to see what you're doing. Holding the ear cleaner bottle in your free hand, squeeze 3-4 drops into the ferret's ear, then fold the ear flap down and gently massage for a few seconds; this loosens up the wax and dirt. Your ferret will be very squirmy when the drops first enter the ear. This is probably because the cleaner is a bit cold. You can try warming the cleaning solution up a bit before using it by placing the bottle in a pan of warm water for a few minutes. After you have massaged the ear flap, using a clean cotton swab(q-tip) gently clean the inner grooves of the ear. Do not go down into the ear canal as you can rupture the ear drum. You'll probably use quite a number of q-tips as ferret ears can hold A LOT of dirt. Make sure you clean the ear thoroughly. There are lots of little grooves and corners where dirt can hide. There is a little "pocket" toward the back of the ear that can harbor quite a bit of dirt and because it sometimes gets overlooked, it doesn't always get cleaned like it should. Once you're done with that ear, clean the other in the same way. You may want to release them from the scruff and allow the ferret to relax and enjoy a treat before you clean the other ear. If you have a ferret who will not hold still no matter what you do, have another person offer them a treat during the ear cleaning as a distraction.
The only difference in the second method is to put a small amount of the ear cleaning fluid in a dish or cap(bottle) so you can dip the cotton swabs in, then clean the ears rather than putting the drops directly in. If you feel that your ferret is becoming too stressed during ear cleanings, stop for frequent "treat breaks" to see if that helps. If not, stop the cleaning altogether and leave it for later in the day or for another day. Ear cleaning is important, but there is no sense in getting the ferret worked up or stressed out over it.
Also, make sure your ferret is comfortable with having your hand that close to the side of it's mouth(the side of the hand you use for cleaning the ear will be right next to the ferret's jaw). Many a ferret owner has been quite suprised at getting bitten during an ear cleaning. Once the ferret is used to it, they generally will stop this behavior.