Ferret

This article is about the mammal. For other uses, see Ferret (disambiguation).

Ferret
Conservation status
Domesticated
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Order:	Carnivora
Family:	Mustelidae
Genus:	Mustela
Species:	M. putorius
Subspecies:	M. p. furo
Trinomial name
Mustela putorius furo Linnaeus, 1758
Synonyms
Mustela furo Linnaeus, 1758

The ferret is a domesticated mammal of the type Mustela putorius furo. Ferrets are sexually dimorphic predators with males being substantially larger than females. They typically have brown, black, white, or mixed fur. They have an average length of 20 inches (51 cm) including a 5 inch (13 cm) tail, weigh about 1.5–4 pounds (0.7–2 kg), and have a natural lifespan of 7 to 10 years.^[1]

Several other small, elongated carnivorous mammals belonging to the family Mustelidae (weasels) also have the word ferret in their common names, including an endangered species, the Black-footed Ferret. The ferret is a very close relative of the polecat, but it is as yet unclear whether it is a domesticated form of the European Polecat, the Steppe Polecat, or some hybrid of the two.

The history of the ferret's domestication is uncertain, like that of most other domestic animals, but it is likely that ferrets have been domesticated for at least 2,500 years. They are still used for hunting rabbits in some parts of the world today, but increasingly they are kept simply as pets.

Being so closely related to polecats, ferrets are quite easily able to hybridize with them, and this has occasionally resulted in feral colonies of polecat-ferret hybrids that have been perceived to have caused damage to native fauna, perhaps most notably in New Zealand. As a result, some parts of the world have imposed restrictions on the keeping of ferrets.

Biology

Characteristics

As described by the Oakland Zoo,

Ferrets have a long and slender body covered with brown, black, white, or mixed fur ... Average length is 20 inches including a 5-inch tail. They weigh 1.5 to 4 pounds, with males substantially larger than females ... Gestation is 42 days, litters are usually 3 to 7 young, but sometimes more. Females may have two to three litters annually. Young are weaned after 3 to 6 weeks and become independent at 3 months. Sexual maturity may come at 6 months. Average life span is 8 years.^[2]

—Conservation and Education: Oakland Zoo

Behavior

Ferrets are crepuscular, which means they spend 14–18 hours a day asleep and are most active around the hours of dawn and dusk.^[3] Unlike their polecat ancestors, which are solitary animals, most ferrets will live happily in social groups. A group of ferrets is commonly referred to as a "business."^{[citation needed]} They are territorial, like to burrow, and prefer to sleep in an enclosed area.^[4]

Like many other carnivores, ferrets have scent glands near their anus, the secretions from which are used in scent marking. It has been reported that ferrets can recognize individuals from these anal gland secretions, as well as the sex of unfamiliar individuals.^[5] Ferrets may also use urine marking for sex and individual recognition.^[6]

As with skunks, ferrets can release their anal gland secretions when startled or scared, but the smell is much less potent and dissipates rapidly. Most pet ferrets in the US are sold descented (anal glands removed).^[7] In many other parts of the world, including the UK and other European countries, de-scenting is considered an unnecessary mutilation.

When excited, they may perform a routine commonly referred to as the weasel war dance, characterized by a frenzied series of sideways hops and bumping into things. Despite its zeal, this is not aggressive but is a joyful invitation to play. It is often accompanied by a soft clucking noise, commonly referred to as dooking.^[8] When agitated or upset, on the other hand, ferrets will make a distinct hissing noise.^[9]

Diet

Ferrets are obligate carnivores.^[10] The natural diet of their wild ancestors consisted of whole small prey, i.e., meat, organs, bones, skin, feathers, and fur.^[11]

Dentition

Ferret dentition

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—located at the sides of the mouth, directly behind the canines. The ferret uses these teeth to cut through flesh, using them in a scissors action to cut 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.

Health

Main article: Ferret health

Ferrets are known to suffer from several distinct health problems. Among the most common are cancers affecting the adrenal glands, pancreas, and lymphatic system. Viral diseases include canine distemper and influenza. Health problems can occur in unspayed females when not being used for breeding. Certain health problems have also been linked to ferrets being neutered before reaching sexual maturity. Certain colors of ferret may also carry a genetic defect known as Waardenburg syndrome. Similar to domestic cats, ferrets can also suffer from hairballs and dental problems.

History of domestication

Women hunting rabbits with a ferret in the Queen Mary Psalter

In common with most domestic animals, the original reason for ferrets' being domesticated by human beings is uncertain, but it may have involved hunting. It was most likely domesticated from the European polecat (Mustela putorius), although it is also possible that ferrets are descendants of the Steppe polecat (Mustela eversmannii), or some hybridization thereof.^[12] Analysis of mitochondrial DNA suggests that ferrets were domesticated around 2,500 years ago, although what appear to be ferret remains have been dated to 1500 BC.^[13] It has been claimed that the ancient Egyptians were the first to domesticate ferrets, but as no mummified remains of a ferret have yet been found, or any hieroglyph of a ferret, and no polecat now occurs wild in the area, that idea seems unlikely.^[14]

The Greek word ictis occurs in a play written by Aristophanes, The Acharnians, in 425 BC. Whether this was a reference to ferrets, polecats, or the similar Egyptian Mongoose is uncertain.^[15] The name "ferret" is derived from the Latin furittus, meaning "little thief", a likely reference to the common ferret penchant for secreting away small items.^[16] Ferrets were probably used by the Romans for hunting.^[17][18]

Colonies of feral ferrets have established themselves in areas where there is no competition from similarly sized predators, such as in the Shetland Islands and in remote regions in New Zealand. Where ferrets coexist with polecats, hybridization is common. It has been claimed that New Zealand has the world's largest feral population of ferret-polecat hybrids.^[19] In 1877, farmers in New Zealand demanded that ferrets be introduced into the country to control the rabbit population, which was also introduced by humans. Five ferrets were imported in 1879, and in 1882–1883, 32 shipments of ferrets were made from London, totaling 1,217 animals. Only 678 landed, and 198 were sent from Melbourne, Australia. On the voyage, the ferrets were mated with the European polecat, creating a number of hybrids that were capable of surviving in the wild. In 1884 and 1886, close to 4,000 ferrets and ferret hybrids, 3,099 weasels and 137 stoats were turned loose.^[20] Concern was raised that these animals would eventually prey on indigenous wildlife once rabbit populations dropped, and this is exactly what happened to New Zealand bird species which previously had no mammalian predators.

Ferreting

Main article: Rabbiting

Muzzled ferret flushing a rat, as illustrating in Harding's Ferret Facts and Fancies (1915)

For millennia, the main use of ferrets was for hunting, or ferreting. With their long, lean build, and inquisitive nature, ferrets are very well equipped for getting down holes and chasing rodents, rabbits and moles out of their burrows. Caesar Augustus sent ferrets or mongooses (named "viverrae" by Plinius) to the Balearic Islands to control the rabbit plagues in 6 BC.^[21][22] They are still used for hunting in some countries, including the United Kingdom, where rabbits are considered a plague species by farmers. The practice is illegal in several countries where it is feared that ferrets could unbalance the ecology. In 2009 in Finland, where ferreting was previously unknown, the city of Helsinki began to use ferrets to restrict the city's rabbit population to a manageable level. Ferreting was chosen because in populated areas it is considered to be safer and less ecologically damaging than shooting the rabbits. In England, in 1390, a law was enacted restricting the use of ferrets for hunting to the relatively wealthy:

it is ordained that no manner of layman which hath not lands to the value of forty shillings a year shall from henceforth keep any greyhound or other dog to hunt, nor shall he use ferrets, nets, heys, harepipes nor cords, nor other engines for to take or destroy deer, hares, nor conies, nor other gentlemen's game, under pain of twelve months' imprisonment.^[23]

Ferrets were first introduced into the New World in the 17th century, and were used extensively from 1860 until the start of World War II to protect grain stores in the American West from rodents.

Ferrets as pets

A ferret in a war dance jump.

In the United States, ferrets were relatively rare pets until the 1980s. A government study by the California State Bird and Mammal Conservation Program estimated that by 1996 about 800,000 domestic ferrets were being kept as pets in the United States.^[24]

Other uses of ferrets

Ferrets are an important experimental animal model for human influenza,^[25][26] and have been used to study the 2009 H1N1 (swine flu) virus.^[27] Smith, Andrews, Laidlaw (1933) inoculated ferrets intra-nasally with human naso-pharyngeal washes, which produced a form of influenza that spread to other cage mates. The human influenza virus (Influenza type A) was transmitted from an infected ferret to a junior investigator, from whom it was subsequently re-isolated.

• Ferrets have been used in many broad areas of research, such as the study of pathogenesis and treatment in a variety of human disease, these including studies into cardiovascular disease, nutrition, respiratory diseases such as SARS and human influenza, airway physiology,^[28] cystic fibrosis and gastrointestinal disease.
• Because they share many anatomical and physiological features with humans, ferrets are extensively used as experimental subjects in biomedical research, in fields such as virology, reproductive physiology, anatomy, endocrinology, and neuroscience.^[29]

Terminology and coloring

Typical ferret coloration, known as a sable or polecat-colored ferret

Male ferrets are called hobs; female 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"^{[citation needed]}, or historically as a "fesnyng".^[30]

Most ferrets are either albinos, with white fur and pink eyes, or display the typical dark masked Sable coloration of their wild polecat ancestors. In recent years fancy breeders have produced a wide variety of 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. Some national organizations, such as the American Ferret Association, have attempted to classify these variations in their showing standards.^[31]

There are four basic colors. The Sable (including chocolate and dark), Albino, Dark Eyed White (DEW), and the silver. All the other colors of a ferret are variations on one of these four categories.

Waardenburg-like coloring

Ferrets with a white stripe on their face or a fully white head, primarily blazes, badgers, and pandas, almost certainly carry a congenital defect which shares some similarities to Waardenburg syndrome. This causes, among other things, a cranial deformation in the womb which broadens the skull, white face markings, and also partial or total deafness. It is estimated as many as 75 percent of ferrets with these Waardenburg-like colorings are deaf.

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 mislabelled; the animal is probably a ferret, not a stoat, (for which "ermine" is an alternative name for the animal in its white winter coat). Similarly, the Ermine portrait of Queen Elizabeth the First shows her with her pet ferret, which has been decorated with painted-on heraldic ermine spots.

"The Ferreter's Tapestry" is a 15th-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 were fitted with muzzles were used to chase rabbits out of their warrens and into waiting nets.

Regulation of ferrets as pets

• Australia – It is illegal to keep ferrets as pets in Queensland or the Northern Territory; in the ACT a licence is required.
• Brazil – They are allowed only if they are given a microchip identification tag and sterilized.
• New Zealand – It has been illegal to sell, distribute or breed ferrets in New Zealand since 2002 unless certain conditions are met.^[32]
• Portugal – It is illegal to keep ferrets as pets in Portugal.^{[citation needed]} Ferrets can be used for hunting purposes only and can be kept only 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^[33] and the California Code of Regulations,^[34] although it is not illegal for veterinarians in the state to treat ferrets kept as pets. In November 1995, ferret proponents asked the California Fish and Game Commission to remove the domesticated ferret from the restrictive wildlife list. Additionally, "Ferrets are strictly prohibited as pets under Hawaii law because they are potential carriers of the rabies virus";^[35] the territory of Puerto Rico has a similar law.^[36] Ferrets are restricted by individual cities, such as Washington, DC, and New York City.^[36] They are also prohibited on many military bases.^[36] A permit to own a ferret is needed in other areas, including Rhode Island.^[37] Illinois and Georgia do not require a permit to merely possess a ferret, but a permit is required to breed ferrets.^[38][39] It was once illegal to own ferrets in Dallas, Texas,^[40] but the current Dallas City Code for Animals includes regulations for the vaccination of ferrets.^[41] Pet ferrets are legal in Wisconsin, but an import permit from the state department of agriculture is required to bring one into the state.^[42]
• Japan – In Hokkaido prefecture, ferrets must be registered with local government.^[43] 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.^[44]

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 import restrictions.^[45]

European Union

As of July 2004, dogs, cats, and ferrets can travel freely within the European Union under the Pet passport 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. Ferrets occasionally need to be quarantined before entering the country. PETS travel information is available from any EU veterinarian or on government websites.

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.^[46]

See also

• Ferret legging
• Stoats in New Zealand

References

Notes

1. ^ Bradley Hills Animal Hospital, Bethesda, Maryland, USA, on lifespan of Ferrets
2. ^ Anon. "Ferret". Conservation and Education:Oaklands Zoo. http://www.oaklandzoo.org/animals/mammals/ferret/. Retrieved 29 January 2010. 
3. ^ Anon. "Ferrets". Pet Health Information. Pet Health Information. http://www.pethealthinfo.org.uk/ferrets/. Retrieved 29 January 2010. 
4. ^ Brown, Susan, A. "Inherited behavior traits of the domesticated ferret". weaselwords.com. http://www.weaselwords.com/page/ferret_art036.php. Retrieved 29 January 2010. 
5. ^ Clapperton, BK; Minot EO, Crump DR (April 1988). "An Olfactory Recognition System in the Ferret Mustela furo L. (Carnivora: Mustelidae)". Animal Behaviour (Academic Press) 36 (2): 541–553. doi:10.1016/S0003-3472(88)80025-3. 
6. ^ Zhang, JX; Soini HA, Bruce KE, Wiesler D, Woodley SK, Baum MJ, Novotny MV (November 2005). "Putative Chemosignals of the Ferret (Mustela furo) Associated with Individual and Gender Recognition". Chemical Senses (Oxford University Press) 30 (9): 727–737. doi:10.1093/chemse/bji065. PMID 16221798. Online. http://chemse.oxfordjournals.org/cgi/content/full/30/9/727#BIB12. Retrieved 2007-02-25. 
7. ^ Mitchell, Mark A.; Tully, Thomas N. (2009). Manual of exotic pet practice. Elsevier Health Sciences. p. 372. ISBN 9781416001195. http://books.google.com/books?id=JMTUKwzPEvwC&pg=PA372. 
8. ^ Schilling, Kim and Brown, Susan. Ferrets for Dummies. For Dummies, 2007, p. 302.
9. ^ Tynes, Valerie V. (2010). Behavior of Exotic Pets. Chichester, West Sussex: Blackwell Pub.. pp. 234. ISBN 9780813800783 0813800781. 
10. ^ Article on ferret clinical pathology by Bruce H. Williams, Armed Forces Institute of Pathology: "... the ferret, being by nature an obligate carnivore, has an extremely short digestive tract, and requires meals as often as every four to six hours."
11. ^ Rethinking The Ferret Diet – Info about species-appropriate diets, and the negative effects of commercially prepared diets, written by a veterinarian.
12. ^ Lewington (2007), p. 6.
13. ^ Glover, James. "The Ancestry of the Domestic Ferret or a white and brown and black ferret". PetPeoplesPlace.com. http://www.petpeoplesplace.com/resources/advice/small_pets/38.htm. Retrieved 2006-09-12. 
14. ^ Church, Bob. "Ferret FAQ — Natural History". ferretcentral.org. http://www.ferretcentral.org/faq/history.html#domestication. Retrieved 2007-08-25. 
15. ^ Thomson (1951)
16. ^ Merriam-Webster's entry on "ferret"
17. ^ Matulich, Erika, Ph.D. (2000). "Ferret Domesticity: A Primer.". Ferrets USA. http://www.cypresskeep.com/Ferretfiles/Domestic-FUSA.htm. Retrieved 2008-03-05. 
18. ^ Brown, Susan, DVM. "History of the Ferret". http://www.veterinarypartner.com/Content.plx?P=A&A=496. Retrieved 2008-03-05. 
19. ^ "Feral Ferrets in New Zealand". California's Plants and Animals. California Department of Fish and Game. http://www.dfg.ca.gov/hcpb/species/nuis_exo/ferret/ferret_issues_3.shtml. Retrieved 2006-09-12. 
20. ^ "Rabbit control". A Hundred Years of Rabbit Impacts, and Future Control Options. New Zealand Ministry of Agriculture and Forestry (MAF) Rabbit Biocontrol Advisory Group. http://www.maf.govt.nz/MAFnet/articles-man/rbag/rbag0010.htm. Retrieved 2006-09-12. ^{[dead link]}
21. ^ Plinius the Elder, Natural History, 8 lxxxi 218 (in Latin)
22. ^ Pliny the Elder (1601). "LV. Of Hares and Connies.". Natural History, Book VIII. Philemon Holland (trans). http://penelope.uchicago.edu/holland/pliny8.html. Retrieved 19 April 2011. 
23. ^ Mackay, Thomas, ed. (1891). Plea for Liberty. D. Appleton and Co. http://www.econlib.org/LIBRARY/LFBooks/MckyT/mckyPL3.html. Retrieved 2007-06-26. 
24. ^ Jurek, R.M. 1998. A review of national and California population estimates of pet ferrets. Calif. Dep. Fish and Game, Wildl. Manage. Div., Bird and Mammal Conservation Program Rep. 98-09. Sacramento, CA. 11 pp.
25. ^ Matsuoka Y, Lamirande EW, Subbarao K (May 2009). "The ferret model for influenza". Current Protocols in Microbiology. http://www.currentprotocols.com/protocol/mc15g02. Retrieved 27 January 2010. 
26. ^ Maher JA, DeStefano J (2004). "The ferret: an animal model to study influenza virus". Lab Anim (NY) 33 (9): 50–53. doi:10.1038/laban1004-50. PMID 15457202. 
27. ^ van den Brand JMA, Stittelaar KJ, van Amerongen G, et al. (2010). "Severity of pneumonia due to new H1N1 influenza virus in ferrets is intermediate between that due to seasonal H1N1 virus and highly pathogenic avian influenza H5N1 virus". J Infect Dis 201 (7): 993–999. doi:10.1086/651132. PMID 20187747. 
28. ^ see Abanses, Arima and Rubin, Vicks VapoRub Induces Mucin Secretion, Decreases Ciliary Beat Frequency, and Increases Tracheal Mucus Transport in the Ferret Trachea, CHEST, January 2009 vol. 135 no. 1 143-148
29. ^ Crawford, Richard L. and Adams, Kristina M. "Information Resources on the Care and Welfare of Ferrets", USDA Animal Welfare Information Center, 2006.
30. ^ Fesnyng – definition of Fesnyng by the Free Online Dictionary. Retrieved 2009-12-29.
31. ^ "American Ferret Association: Ferret Color and Pattern Standards". Ferret.org. http://www.ferret.org/events/colors/colorchart.html. Retrieved 2008-11-30. 
32. ^ Wildlife Act 1953 – Schedule 8
33. ^ "Fish and Game Code Section 2118". California Codes. State of California. http://www.leginfo.ca.gov/cgi-bin/waisgate?WAISdocID=69408513066+1+0+0&WAISaction=retrieve. Retrieved 2006-09-19. ; the Code states, in part: "animals of the families Viverridae and Mustelidae in the order Carnivora are restricted because such animals are undesirable and a menace to native wildlife, the agricultural interests of the state, or to the public health or safety."
34. ^ "Section 671(c)(2)(K)(5): "Family Mustelidae"". California Code Of Regulations, Title 14: Natural Resources, Division 1: "Fish And Game Commission — Department Of Fish And Game", Subdivision 3: "General Regulations", Chapter 3: "Miscellaneous",Section 671: "Importation, Transportation and Possession of Live Restricted Animals". http://weblinks.westlaw.com/Search/default.wl?RP=%2FWelcome%2FFrameless%2FSearch%2Ewl&n=1&action=Search&bhcp=1&CFID=0&db=ca%2Dadc&method=TNC&query=ci%28%2214+CA+ADC+s+671%22%29&recreatepath=%2Fsearch%2Fdefault%2Ewl&RLT=CLID%5FQRYRLT132814199&RLTDB=CLID%5FDB102814199&search=Search&section=671&sp=CCR%2D1000&spolt=Return+to+the+California+Code+of+Regulations+Service&sposu=http%3A%2F%2Fgovernment%2Ewestlaw%2Ecom%2Flinkedslice%2Fdefault%2Easp%3FSP%3DCCR%2D1000&spou=http%3A%2F%2Fgovernment%2Ewestlaw%2Ecom%2Flinkedslice%2Fdefault%2Easp%3FSP%3DCCR%2D1000&ssl=n&strRecreate=no&sv=Split&tempinfo=FIND&title=14&RS=WEBL6.09&VR=2.0&SPa=CCR-1000. Retrieved 2006-09-19.  Ferrets are not among the exceptions to the classification "Those species listed because they pose a threat to native wildlife, the agriculture interests of the state or to public health or safety are termed "detrimental animals" and are designated by the letter "D".
35. ^ "News Release:Illegal Ferret Found in Kailua". State of Hawaii Department of Agriculture. http://www.hawaiiag.org/hdoa/newsrelease/00-21.htm. Retrieved 2006-09-19. 
36. ^ ^{a b c} Katie Redshoes. "Are Ferrets Legal in ...?" (HTTP). List of Ferret-Free Zones. http://home.netcom.com/~redshoes/ffztable.html. Retrieved 2007-08-26. 
37. ^ "R.I. Ferret Regulations" (PDF). State of Rhode Island and Providence Plantations Department of Environmental Management. June 27, 1997. http://www.dem.ri.gov/pubs/regs/regs/fishwild/f_wferet.pdf. Retrieved 2007-07-05. 
38. ^ "Wild Bird and Game Bird Breeder Permit Application" (PDF). Illinois Department of Natural Resources. Archived from the original on 2006-08-05. http://web.archive.org/web/20060805100847/http://dnr.state.il.us/admin/systems/06/game_app.pdf. Retrieved 2006-09-12. 
39. ^ "Wild Animal License Application" (PDF). Georgia Department of Natural Resources. http://www.georgiawildlife.com/sites/default/files/uploads/wildlife/hunting/pdf/special_permits/Wild_Animal_License_Application.pdf. Retrieved 2010-03-05.  OCGA 27-5-5(K)Order Carnivora (weasels, ferrets, cats, bears, wolves, etc.) -- All species, except that a European ferret (Mustela putorius furo) may be sold, purchased, exhibited, or held as a pet without a license or permit; provided that the ferret owner can provide valid documentation that the ferret was sexually neutered prior to seven months of age and is vaccinated against rabies with a properly administered vaccine approved for use on ferrets by the United States Department of Agriculture.
40. ^ "Dallas". Prohibited by Ordinance. Ferret Lover's Club of Texas. 1996 – 2005. http://www.texasferret.org/lglprohibord.shtml. Retrieved 2006-09-19. 
41. ^ "Animal Services". Dallas City Code, Chapter 7: "Animals"; Article VII: "Miscellaneous". American Legal Publishing Corporation. http://www.amlegal.com/nxt/gateway.dll/Texas/dallas/volumei/preface?f=templates$fn=default.htm$3.0$vid=amlegal:dallas_tx. Retrieved 2006-09-19. 
42. ^ "Companion Animals". Wisconsin Department of Agriculture, Trade, and Consumer Protection. http://www.datcp.state.wi.us/ah/agriculture/animals/movement/companion_animals.jsp. Retrieved 2008-11-13. 
43. ^ "Hokkaido Animal Welfare and Control Ordinance". Hokkaido Animal Welfare and Control Ordinance Chapter 2, Section 3.. http://www.pref.hokkaido.lg.jp/ks/skn/aigo/jyourei.htm. Retrieved 2009-04-10. ^{[dead link]}
44. ^ "Importation of Ferrets into Australia, Import Risk Analysis — Draft Report" (PDF). Australian Quarantine and Inspection Service (AQIS). August 2000. Archived from the original on 2006-09-10. http://web.archive.org/web/20060910063747/http://www.daff.gov.au/corporate_docs/publications/pdf/market_access/biosecurity/animal/2000/00-036a.pdf. Retrieved 2006-09-12. 
45. ^ "Importation of Foxes, Skunks, Raccoons and Ferrets". Pet Imports. Canadian Food Inspection Agency. 2006-03-20. http://www.inspection.gc.ca/english/anima/heasan/import/foxrene.shtml. Retrieved 2006-09-12. ^{[dead link]}
46. ^ "PETS: How to bring your ferret into or back into the UK under the Pet Travel Scheme (PETS)". Animal health & welfare. Department of Environment Food and Rural Affairs (defra) © Crown copyright 2006. http://www.defra.gov.uk/animalh/quarantine/pets/ferretpets.htm. Retrieved 2006-09-12. 

Bibliography

• Lewington, John H. (2007). Ferret Husbandry, Medicine and Surgery (2nd ed.). Elsevier. ISBN 9780702028274. 
• Thomson, P. D. (1951). "A History of the Ferret". Journal of the History of Medicine and Allied Sciences vi (Autumn): 471–480. doi:10.1093/jhmas/VI.Autumn.471. 

External links

• Isaacsen, Adolph (1886) All about ferrets and rats