Envigo uses well-established techniques to successfully produce timed mated rats, mice, hamsters, guinea pigs, and rabbits. Envigo uses an impedance meter for determining the stage of estrus in rats.* Timed mated rats and mice are determined by observation of a vaginal plug. Plug date for rodents is considered to be day zero (0) of gestation.

*For timed mated animals fulfilled from Envigo Affiliates in Europe, in general, animals are mated overnight from 16.00 until 08.00 hours. In case of timed-mating during the day, a surcharge of 50% is added to the pregnant animal price. In case a timed-mating (or preparation) set up on a holiday and / or a Sunday, Envigo will charge £ 100/Euro 120 per order. For rabbits the fee is £ 9,70 - Euro 10,70 per rabbits with a minimum charge of £ 115 / Euro 126,50 per order.

Due to the natural variation in the length of gestation, the exact day of parturition cannot be guaranteed. In addition, Envigo cannot guarantee the minimum number or sex of offspring per litter.

Envigo may ship animals which are in late gestation if requested by customer**, as they may deliver their litter while in transit. Requests for credit or replacement of animals shipped in late gestation per customer request may be declined in Envigo’s sole discretion.

**For models fulfilled from Envigo Affiliates in Europe, the last stage of gestation for mice is over 17 days and for rats is over 18 days, each at shipping. To comply with UK guidelines, Envigo cannot ship rodents more than 17 days of pregnancy at packing when fulfilled from the UK. Pregnant animals shipped in the UK are transported in accordance with the (Animal Scientific Procedures) Act 1986 and EC 1/2005 Protection of animals during transport.

Envigo does not guarantee that late term animals will not deliver in transit. If animals deliver while in transit, Envigo may charge the full order price.

If problems regarding gestational age or pregnancy are encountered, customers should immediately contact Envigo’s customer service department and provide detailed information regarding the animals involved. Requests for credit and/or replacement animals may generally be declined by Envigo, in its discretion, if appropriate documentation is not supplied to Envigo.

*     Plug guarantee only; no guaranteed pregnancy. Plug date = Day 0.
**     Untimed pregnant rodents will be selected from our breeding colonies on the basis of palpation or visual confirmation. A variation of three to four days gestation can be expected. Envigo is not responsible for actual gestation and/or exact day of littering for untimed pregnant rodents.

To avoid charges, cancellations for timed mated rats, mice, guinea pigs, and hamsters must be received one week prior to mating date, however, cancelled orders for timed mated rabbits will be charged at full price regardless of the amount of notice supplied.

For orders from Envigo’s Affiliates in Europe, when ordering females with litter, customer should take into account that Envigo can’t ship litters which are less than 3 days of age at packing. When animals are sourced from the UK, the minimum age of the litter must be at least 7 days at packing. If customer’s research project requires such litters, Envigo recommends ordering timed mated pregnant rats and mice which can litter at customer’s facility.

U.S.