Ferret Facts

ADULT WEIGHT: 1-5.5lbs (500g-2.5kg). Varies considerably according to time of year (up to 40%).

ADULT DIMENSIONS: 17=24" (44-60cm) including tail. Male can be twice as large as female.

AVERAGE LIFESPAN: 5-6 years in laboratory. Up to 10 years pets (older have been known).


RESPIRATORY RATE: 30-40 per minute.

HEART RATE: 220-250 beats per minute.

RECTAL TEMP: Average 38.8C (101.8F). Range 37.8-40C (100-104F).

TEETH: Incisors 3/3, canines 1/1, premolars 3/3, molars 1/2. Supernumary incisors common.

TOES: 5 on each foot.

NIPPLES: 8 (male and female).

VERTEBRAE: C7, T14, L6, S3, COL14-18. 14 pairs of ribs.

OTHER ANATOMY: No caecum, appendix and male prostate gland. Sweat glands not well developed.

ENVIRONMENT: Optimum 15-20C (60-70F max.). Heat prostration likely at 32C 90F).

SEXING: Ano-genital distance of male at least twice that of female.

PUBERTY: 240-250 days.

SEXUAL MATURITY: 9-12 months, or the spring following birth.

AGE TO BREED: Male 365 days, female 275 days.

BREEDING SEASON: Photoperiodically triggered - possibly 16 hours daylight. Main breeding season March - August in Britain (male testes begin to descend December/January and regress by July, female in oestrus any time from March to October.

SEASON SIGNS: Female has swollen vulva, male has swollen testes.

DURATION OF OESTRUS: Continuous until mated or until end of season and very prolonged if unmated. Ovulation induced by male stimulus (behaviour and coitus).

DURATION OF MATING: 10 minutes to several hours - probably 1 hour on average.

OVULATION: 30 hours after mating.

REDUCTION OF VULVA: 7-10 days, complete within 2-3 weeks of mating.

PALPATION: 10 days after vulva reduced.

GESTATION: Average 42 days. (Range 38-44 days; at 45 days kits die.)

LITTERS PER YEAR: Two possible (up to 5 under controlled photoperiod).

NESTING: Starts building 10-12 days before birth.

OTHER BIRTH SIGNS: Mammary glands.

POST-NATAL OESTRUS: 1-2 weeks after weaning.

LITTER SIZE: 2-17 (average 8, norm. 6-9) - more in first litter of season than in second.

BIRTHWEIGHT: .5oz (5-15g).

DECIDUOUS TEETH: Begin to erupt at 10-14 days.

CANINES: 47-52 days.

EYES/EARS OPEN: 21-37 days.

FUR: Almost naked at birth, some by 9 days, good woolly coat by 4-5 weeks.

OUT OF NEST: First ventures usually 3-4 weeks.

WEANING AGE: 6-8 weeks.

WEANING WEIGHT: 10.5-17.5 oz (300-500g).


1st POSSIBLE MATING: 6 months.

1st NORMAL MATING: 12 months.

(Excerpt from "The Complete Book of Ferrets" by Val Porter & Nicholas Brown.)