Ferrets

Ferrets have become increasingly important in biological research. In fact, they are now being used in physiology, pharmacology, virology/immunology, behavior, parasitology, toxicology and many other areas of research.

Man's domestication of the ferret can be traced back to the 4th century B.C., when the animals were used to exterminate rats and snakes in Europe and Asia. Over the past 40 years, breeding stock has been developed with gentle temperaments, so most can be handled without gloves.

Ferrets adapt well to caging and can be kept individually or communally. Space requirements for exercise are minimal. They habitually use one toilet location in an area opposite of where they sleep, making it easy to collect fecal samples. Common litter materials and automatic waterers make caring for ferrets conveniently similar to caring for other laboratory animals such as rabbits, guinea pigs, mice, etc.

The gestation period of the ferret is a uniform 42 days, with litter sizes ranging from 6-10. They are weaned at 6 weeks and at 9 weeks of age, they are one-half of their mature size. Mature weight for male ferrets is 1800 grams, with body length at 16 inches (without tail). Female ferrets are considerably less formidable at 900 grams and 14 inches in length (without tail). Ferrets are nocturnal creatures, usually spending a great deal of time sleeping.

Unique anatomical variants include the large intestine, which has no anatomical division between the ileum and the colon, making it appear as one undifferentiated tube. Another interesting variant in the ferret is the existence of a single central ascending artery instead of the more common bilateral carotid arteries.

Finally, the respiratory system of the ferret is adapted to its burrowing nature. The ferret's chest walls are extremely compliant and the total lung capacity and inspiratory reserve are very large in relation to body size. The long trachea and larger diameter airways in ferrets result in a much lower pulmonary and central airway resistance than is seen in other laboratory animals of comparable size.

The disadvantages of using the ferret for research are few. They are susceptible to and should be vaccinated for canine distemper, and like cats, lack easily accessible veins, making intravenous drug administration virtually impossible.

Sources: Laboratory Management of the Ferret for Research, K.D. Moody, T. A. Bowman and C. M. Lang, Lab Animal Science 35:272-279 (1985)