Ferret (Mustela putorius furo)
Natural history
The domestic ferret is probably derived from the European polecat (M. putorius putorius) (Chitty 2009). Ferrets serve as working animals (in the age-old tradition of “ferreting”), pets, and laboratory animals. In the United States, ferrets are raised on ferret farms where they are spayed or neutered at 6 weeks of age. After each procedure, a tattoo is placed on the ear pinna. Male ferrets are called “hobs”, females are “jills”, and juveniles are “kits”.
Taxonomy
Class: Mammalia
Order: Carnivora
Family: Mustelidae – weasels, skunks, stoats, otters, badgers
Colors
Ferrets come in a variety of colors with albino and sable or fitch being the two original ferret colors. Other color standards listed by The American Ferret Association lists include black, black sable, champagne, and chocolate. Pattern standards include panda, dark-eyed white, roan, and color point or Siamese.
Ferrets with strong white features on the head have a genetic disposition for deafness (Fehr and Sassenburg 2015).
Diet
Ferrets are obligate carnivores. Free-ranging ferrets feed on fresh whole carcasses of their prey (Chitty 2009). In the US, pet ferrets should be fed a high-quality ferret food. Cat food that contains animal-based protein can be used if no ferret food is available (Bell 1999). Crude protein should be 30-35% and fat content should be 15-20%. Avoid kitten food as this contains higher fat levels than is necessary.
In the UK and Europe, pets are sometimes offered high-quality, fresh carcass instead of ferret food (Chitty 2009). Vitamin supplements may be necessary when feeding defrosted carcasses (Chitty 2009).
Taste preferences develop in the first months, therefore different food should be offered to ferrets in a young age (Quesenberry & Carpenter 2012).
Husbandry
Although technically nocturnal, ferrets easily adjust their schedule to human activity (Ball 2002). House ferrets in multilevel cages with solid-bottom flooring. Provide toweling and other items for burrowing and hiding. Ferrets are also commonly litter pan trained (Boyce 2001).
Never allow ferrets free roam of the home. Instead supervised play should be limited to a ferret-proofed room or region of the home.
Normal physiologic values
| Temperature | 100-103 F | 37.8-39.4 C |
| Pulse | 180-250 bpm | |
| Respiration | 30-40 bpm | |
| Body weight | 600-2000g | Males are larger |
| Mean life span | 6-10 y | |
| Sexual maturity | 9-12 months | |
| Gestation | 41-42 days | |
| Litter size | 8 | |
| Birth weight | 6-12 g | |
| Teeth first erupt | 3 weeks | |
| Eyes open | 32-34 days | |
| Weaning age | 6-8 weeks | |
| Daily water intake | 75-100 ml | |
| Target environmental temperature: | 65-70 F | |
| Target environmental humidity: | 40-65% |
Anatomy / physiology
| Integumentary | Seasonal molts occur, especially in ferrets living outdoors, coats lighten during the summer and darken during the winter. Even when descented and castrated, sebaceous skin glands convey a musky odor (Chitty 2009). A lack of sweat glands makes ferrets vulnerable to heat stress. |
| Dental formula Gastrointestinal | I3/3 C1/1 PM3/3 M1/2 Short, simple digestive tract with no cecum or ileocolic valve. |
| Musculoskeletal | Ferrets have a slender and elongated body shape with a very flexible spine. The vertebral formula is C. 7, T. 15, L. 5-7, S. 3 (fused), Cd. 18. The thorax is very long with 15 paired ribs.
The extremities are relatively short, and there are five toes on each paw (Chitty 2009). Ferrets possess powerful jaw tone due their very strong masticatory muscles (Chitty 2009). |
| Special Senses | Small pinnae and well-developed bullae. Olfactory sense highly developed; visual sense moderately developed (Chitty 2009). |
| Urogenital | Renal cysts are common incidental findings. The male ferret possesses a J-shaped os penis. Females are induced ovulators. |
| Cardiovascular | The heart lies more caudal in the chest than in similarly sized dogs and cats. |
| Respiratory | A very narrow ventral space in the nasal conchae makes passing a nasogastric tube difficult. |
| Hematopoietic | Blood types have not been identified in ferrets and transfusion can be performed (sans cross-matching) with little risk (Marini 2014). |
| Endocrine | Early neutering and a lack of natural photoperiod may predispose ferrets to adrenocortical disease. |
Ferrets are sweet natured, gregarious animals that may be minimally
restrained. Ferrets may be manually restrained:
- Scruff and stretch. Instead of holding the rear limbs as in a cat, grasp the pelvis in one hand.
- Roll the ferret up in a thin towel to create a ferret burrito.
The total blood volume in ferrets is 40-60 ml; up to 10% can be withdrawn in healthy individuals.
Large volumes: Jugular vein, cranial vena cava
Small volumes: Cephalic vein or lateral saphenous vein
The ferret jugular vein is located more lateral than in a cat.
There is thickened skin over the skin of the neck in hobs.
Preventive medicine
Annual examinations are recommended until ferrets are 3-4 years old, then biannual exams are recommended. Almost all pet ferrets in the United States are descented and neutered before they enter the market. As induced ovulators, all female ferrets should be spayed to prevent the risk of persistent estrus and potentially fatal anemia.
Surgically sterilized females also have a high risk for the development of hyperadrenocorticism. Chemical castration with a Deslorelin implant reduces the risk of adrenal disease (Schoemaker et al 2018).
Vaccinate against rabies virus and canine distemper virus (CDV). Ferrets are exquisitely sensitive to CDV and postvaccinal distemper infection has been reported after use of vaccines for dogs. Therefore ferrets should never be vaccinated with products intended for use in dogs (Meredith 2009).
Important medical conditions
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References
References
Ball RS. Husbandry and management of the domestic ferret. Lab Anim 31(5):37-42, 2002.
Banks RE, Sharp JM, Doss SD, Vanderford DA. Exotic Small Mammal Care and Husbandry. Durham, NC: Wiley-Blackwell; 2010.
Bell JA. Ferret nutrition. Vet Clin North Am Exot Anim Pract 2(1):169-92, 1999.
Boyce SW, Zingg BM, Lightfoot TL. Behavior of Mustela putorius furo (the domestic ferret). Vet Clin North Am Exot Anim Pract 4(3):697-712, 2001.
Caplan ER, Peterson ME, Mullen HS, et al. Diagnosis and treatment of insulin-secreting pancreatic islet cell tumors in ferrets: 57 cases (1986-1994). J Am Vet Med Assoc 209(10):1741-1745, 1996.
Chitty J. Ferrets: biology and husbandry. In: Keeble E, Meredith A (ed.). BSAVA Manual of Rodents and Ferrets. BSAVA. 2009, 193-204.
Dyer SM, Cervasio EL. An overview of restraint and blood collection techniques in exotic pet practice. Vet Clin North Am Exot Anim Pract 11:423-443, 2008.
Ehrhart N, Withrow SJ, Ehrhart EJ, Wimsatt JH. Pancreatic islet cell tumor in ferrets: 20 cases (1986-1994). J Am Vet Med Assoc 209(10):1737-1740, 1996.
Erdman SE, Brown SA, Kawasaki TA, et al. Clinical and pathologic findings in ferrets with lymphoma: 60 cases (1982-1994). J Am Vet Med Assoc 208(8):1285-1289, 1996.
Johnson-Delaney CA. The ferret gastrointestinal tract and Helicobacter mustelae infection. Vet Clin North Am Exot Anim Pract 8:197-212, 2005.
Lewington J. Ferrets. In: O’Malley B (ed). Clinical Anatomy and Physiology of Exotic Species. Saunders Elsevier. 2005: 237-261.
Marini RP. Physical examination, preventive medicine, and diagnosis in the ferret. In: Fox JG, Marini RP (eds). Biology and Diseases of the Ferret, 3rd ed. Wiley Blackwell; 2014: 235-258.
Meredith A. Ferrets: systemic viral disease. In: Keeble E, Meredith A (eds). BSAVA Manual of Rodents and Ferrets. BSAVA. 2009, 330-334.
Mitchell MA, Tully TN. Manual of Exotic Pet Practice. St. Louis, MO: Saunders Elsevier; 2009.
Quesenberry KE, Carpenter JW (eds). Ferrets, Rabbits, and Rodents: Clinical Medicine and Surgery, 3rd ed. St. Louis: Elsevier Saunders; 2012: 1-156.
Schoemaker N, Drijver E, Bandsma J, et al. Longitudinal evaluation of adrenal gland volume in chemically versus surgically neutered ferrets. Proc ExoticsCon 2018:91.
Weiss CA, Williams BH, Scott MV. Insulinoma in the ferret: clinical findings and treatment comparison of 66 cases. J Am Anim Hosp Assoc 34:471-475, 1998.
Pollock C, Parmentier S. Basic information sheet: Ferret. Feb 4, 2019. LafeberVet Web site. https://lafeber.com/vet/basic-information-for-ferrets/