Dental health
Dental health is a very important part of any ferret's health, and should not be neglected.
Ferrets have four types of teeth (the number includes maxillary(upper) and mandibular(lower) teeth)
Twelve small teeth (only a couple of millimeters) located between the canines in the front of the mouth. These are known as the incisors and are used for grooming.
Four Canines used for killing prey.
Twelve Premolar teeth that the ferret uses to chew food, and are located at the sides of the mouth, directly behind the canines. The ferret being a carnivore uses these teeth to cut flesh, using them as scissors, cutting the meat into digestible chunks.
Six Molars (Two on top and four on the bottom) at the far back of the mouth are used to crush food.

Tartar
Dental calculus (tartar) is a hard substance formed on the teeth from the mineralization of plaque.
Dental tartar primarily comes from wet food which get stuck to the teeth for extended periods of time. The best way to avoid tartar is to feed the ferret raw meat, bones and preferably whole prey. The biomechanics of consuming meat and bones will keep the teeth clean.
Tartar, left to itself may lead to gingivitis which in turn can lead to a dental abscess, bone loss, infections which may spread bacteria through the bloodstream to internal organs and lead to death if not treated.
Tartar can be removed either mechanical or by ultrasound at a veterinarian (this usually involves anesthesia), a small toothbrush can also be used as a preventive measure if one is unable to feed the animal with raw meat.
Prevention is better than treatment, and tartar can be prevented by feeding raw food or giving specially made gelatin treats for ferrets.

Abrasion
Dental abrasion or tooth wear is common in ferrets, and is caused by mechanical wear of the teeth.
Eating manufactured dry food (kibble) will erode (due to the hard and extremely dry kibble) the carnassial teeth of the ferret, the wear from the eating kibble can become significant with old age (after three to five years). If teeth are overly ground down, a ferret cannot use them as scissors to eat raw meat. Tooth erosion eventually affects a ferret's ability to eat solid food.
Dental abrasion can also be caused by excessive chewing on fabrics or toys, and cage biting. If the ferret engages in these activities a lot, it might be a sign of boredom, and more stimulating activities (such as play) should rectify the situation.

Terminology and coloring
Male intact ferrets are called hobs; female intact ferrets are jills. A spayed female is a sprite, a neutered male is a gib, and a vasectomised male is known as a hoblet. Ferrets under one year old are known as kits. A group of ferrets is known as a business, or historically as a fesnyng.
Ferrets are various colors and patterns. Color refers to the color of the ferret's guard hairs, undercoat, eyes, and nose. Pattern refers to the concentration and distribution of color on the body, mask, and nose, as well as white markings on the head or feet when present. The colors and patterns recognized by the American Ferret Association are as follows:
Colors:
Albino
Black
Black Sable
Champagne
Chocolate
Cinnamon
Dark-eyed White (DEW)
Sable
Color patterns:
Standards
Roans
Point (Siamese)
Solids
White patterns:
Blaze
Panda
Mitt
White ferrets were favored in the Middle Ages for the ease in seeing them in thick undergrowth. Leonardo da Vinci's painting Lady with an Ermine is likely mislabeled; the animal is probably a ferret, not a stoat, for which "ermine" is an alternative name (the latter strictly applying only to the animal in its white winter coat). Similarly, the Ermine portrait of Queen Elizabeth the First shows her with her pet ferret, who has been decorated with painted-on heraldic ermine spots.
"The Ferreter's Tapestry" is a fifteenth-century tapestry from Burgundy, France now part of the Burrell Collection housed in the Glasgow Museum and Art Galleries. It shows a group of peasants hunting rabbits with nets and white ferrets. This image was reproduced in Renaissance Dress In Italy 1400-1500, by Jacqueline Herald, Bell & Hyman — ISBN 0-391-02362-4
Gaston Phoebus' Book Of The Hunt was written in approximately 1389 to explain how to hunt different kinds of animals, including how to use ferrets to hunt rabbits. Illustrations show how multicolored ferrets that are fitted with muzzles were used to chase rabbits out of their warrens and into waiting nets.

Regulation on ferrets as pets
Australia - It is illegal to keep ferrets as pets in Queensland or the Northern Territory; in the ACT and Victoria a licence is required.
Brazil - They are only allowed if they are given a microchip identification tag and sterilized.
Iceland - Selling, distributing, breeding and keeping ferrets is illegal in Iceland. New Zealand - It has been illegal to sell, distribute or breed ferrets in New Zealand since 2002.
Portugal - It is illegal to keep ferrets as pets in Portugal. Ferrets can only be used for hunting purposes and can only be kept with a government permit.
United States - Ferrets were once banned in many US states, but most of these laws were rescinded in the 1980s and 90s as they became popular pets. Ferrets are still illegal in California under Fish and Game Code Section 2118 and the California Code of Regulations. Additionally, "Ferrets are strictly prohibited as pets under Hawaii law because they are potential carriers of the rabies virus"; the territory of Puerto Rico has a similar law. Ferrets are restricted by individual cities, such as, Washington, DC and New York City. They are also prohibited on many military bases. A permit to own a ferret is needed in other areas, including Rhode Island. Illinois and Georgia do not require a permit to merely possess a ferret, but a permit is required to breed ferrets. It was once illegal to own ferrets in Dallas, Texas, but the current Dallas City Code for Animals includes regulations for the vaccination of ferrets. Pet ferrets are legal in Wisconsin, but an import permit from the state department of agriculture is required to bring one into the state.
Japan - It is legal to keep ferrets as pets in Japan. In Hokkaido prefecture, ferrets must be registered with local government. In other prefectures, no restrictions apply.

Import restrictions
Australia
Ferrets cannot be imported into Australia. A report drafted in August 2000 seems to be the only effort made to date to change the situation.
Canada
Ferrets brought from anywhere except the US require a Permit to Import from the Canadian Food Inspection Agency Animal Health Office. Ferrets from the US require only a vaccination certificate signed by a veterinarian. Ferrets under three months old are not subject to any restrictions for importation.
European Union
As of July 2004, dogs, cats, and ferrets can travel freely within the European Union under the PETS travel scheme. To cross a border within the EU, ferrets require at minimum an EU PETS passport and an identification microchip (though some countries will accept a tattoo instead). Vaccinations are required; most countries require a rabies vaccine, and some require a distemper vaccine and treatment for ticks and fleas 24 to 48 hours before entry. PETS travel information is available from any EU veterinarian or on government websites.
Japan
Although previously pet ferrets were allowed to be brought into Japan, that is no longer the case. Individual pet ferrets cannot be brought into Japan without proper documents. However, licensed breeders such as Canadian Farms, PVF and Marshall's have a special agreement which still allows the import of ferrets from those companies.
United Kingdom
The UK accepts ferrets under the EU's PETS travel scheme. Ferrets must be microchipped, vaccinated against rabies, and documented. They must be treated for ticks and tapeworms 24 to 48 hours before entry. They must also arrive via an authorized route. Ferrets arriving from outside the EU may be subject to a six-month quarantine.