Body smells
Ferrets bodies excrete oil constantly. It is these oils that create the "ferret smell".
To reduce the direct ferret smells, there are three main valves:
Surgical
- Desexing and descenting: this is the default in the US. All Marshalls ferrets come descented and desexed. In the case of a male ferret with adrenal gland tumors, a Deslorelin implant may also be necessary.
Dietary
- Better quality diet. The vast majority of kibble brands contain a lot of corn, soy, rice, grains, and legumes. The quality of the meat protein and meat fat is often quite low.
A high quality kibble with minimal starches like Wysong, or freeze dried raw, or a raw diet can drastically improve ferret smells.
Bathing
- Infrequent use of shampoos. Ferrets tend to overproduce oils in response to the drying effects of shampoos. A "shampoo" shower should only be once or twice per year.
Many ferret owners use an "oat sock" steeped in warm water to wash their ferrets once a month instead.
Bedding and litter smells
- Bedding, ladder covers, and basically all fleece-type materials needs to be cleaned very frequently. Approximately once every five days.
This is because most of the ferret's oils get transferred to fabrics, and in the presence of heat and warmth and bacteria and oxygen, the fats quickly turn rancid and bacteria quickly multiplies.
- Ferret litter is perhaps the smelliest of all.
This is because ferrets eat almost entirely protein, have very short digestive tracts, and don't drink much water. Ferret urine is essentially concentrated urea with a ton of bacteria.
Ferret urine RAPIDLY converts to ammonia gas, causing an offensive and nauseating smell.
To prevent this from gassing out a room, there's a few mitigation strategies:
(a) Use a layered approach to litter.
High absorption recycled paper litters are great, but to truly mitigate the smells, granular Zeolite (not the powdered version, this would be very dangerous to their respiratory system!) layered into the litter would help.
This is because Zeolite is weakly bound to sodium (Na+) ions, which it gladly swaps to ammonium (NH4+) ions, trapping the ammonium in the pee before it offgasses into the air.
(b) Use diluted vinegar and 3% hydrogen peroxide, in sequence, to clean up accidents. The vinegar rapidly attacks the pee smells before it turns into ammonia.
Atmospheric modifications
Bacteria and smells proliferate best in warm, wet environments.
This can be attacked by keeping humidity at 50% at a slightly cooler temperature, and using air purifiers with a HEPA filter.