Directive 2010/63/EU of the European Parliament and of the CouncilShow full title

1. Mice, rats, gerbils, hamsters and guinea pigs U.K.

In this and subsequent tables for mice, rats, gerbils, hamsters and guinea pigs, ‘enclosure height’ means the vertical distance between the enclosure floor and the top of the enclosure and this height applies over more than 50 % of the minimum enclosure floor area prior to the addition of enrichment devices.

When designing procedures, consideration shall be given to the potential growth of the animals to ensure adequate space is provided (as detailed in Tables 1.1 to 1.5) for the duration of the study.

Table 1.1. Mice U.K.

a Post-weaned mice may be kept at these higher stocking densities for the short period after weaning until issue, provided that the animals are housed in larger enclosures with adequate enrichment, and these housing conditions do not cause any welfare deficit such as increased levels of aggression, morbidity or mortality, stereotypes and other behavioural deficits, weight loss, or other physiological or behavioural stress responses.
	Body weight(g)	Minimum enclosure size(cm2)	Floor area per animal(cm2)	Minimum enclosure height(cm)	Date referred to in Article 33(2)
In stock and during procedures	up to 20	330	60	12	1 January 2017
	over 20 to 25	330	70	12
	over 25 to 30	330	80	12
	over 30	330	100	12
Breeding		330 For a monogamous pair (outbred/inbred) or a trio (inbred). For each additional female plus litter 180 cm2 shall be added.		12
Stock at breedersaEnclosure size950 cm2	less than 20	950	40	12
Enclosure size1 500 cm2	less than 20	1 500	30	12

Table 1.2. Rats U.K.

a In long-term studies, if space allowances per individual animal fall below those indicated above towards the end of such studies, priority shall be given to maintaining stable social structures.
b Post-weaned rats may be kept at these higher stocking densities for the short period after weaning until issue, provided that the animals are housed in larger enclosures with adequate enrichment, and these housing conditions do not cause any welfare deficit such as increased levels of aggression, morbidity or mortality, stereotypes and other behavioural deficits, weight loss, or other physiological or behavioural stress responses.
	Body weight(g)	Minimum enclosure size(cm2)	Floor area per animal(cm2)	Minimum enclosure height(cm)	Date referred to in Article 33(2)
In stock and during proceduresa	up to 200	800	200	18	1 January 2017
	over 200 to 300	800	250	18
	over 300 to 400	800	350	18
	over 400 to 600	800	450	18
	over 600	1 500	600	18
Breeding		800 Mother and litter. For each additional adult animal permanently added to the enclosure add 400 cm2		18
Stock at breedersbEnclosure size1 500 cm2	up to 50	1 500	100	18
	over 50 to 100	1 500	125	18
	over 100 to 150	1 500	150	18
	over 150 to 200	1 500	175	18
Stock at breedersbEnclosure size2 500 cm2	up to 100	2 500	100	18
	over 100 to 150	2 500	125	18
	over 150 to 200	2 500	150	18

Table 1.3. Gerbils U.K.

	Body weight(g)	Minimum enclosure size(cm2)	Floor area per animal(cm2)	Minimum enclosure height(cm)	Date referred to in Article 33(2)
In stock and during procedures	up to 40	1 200	150	18	1 January 2017
	over 40	1 200	250	18
Breeding		1 200 Monogamous pair or trio with offspring		18

Table 1.4. Hamsters U.K.

a Post-weaned hamsters may be kept at these higher stocking densities, for the short period after weaning until issue provided that the animals are housed in larger enclosures with adequate enrichment, and these housing conditions do not cause any welfare deficit such as increased levels of aggression, morbidity or mortality, stereotypes and other behavioural deficits, weight loss, or other physiological or behavioural stress responses.
	Body weight(g)	Minimum enclosure size(cm2)	Floor area per animal(cm2)	Minimum enclosure height(cm)	Date referred to in Article 33(2)
In stock and during procedures	up to 60	800	150	14	1 January 2017
	over 60 to 100	800	200	14
	over 100	800	250	14
Breeding		800 Mother or monogamous pair with litter		14
Stock at breedersa	less than 60	1 500	100	14

Table 1.5. Guinea pigs U.K.

	Body weight(g)	Minimum enclosure size(cm2)	Floor area per animal(cm2)	Minimumenclosure height(cm)	Date referred to in Article 33(2)
In stock and during procedures	up to 200	1 800	200	23	1 January 2017
	over 200 to 300	1 800	350	23
	over 300 to 450	1 800	500	23
	over 450 to 700	2 500	700	23
	over 700	2 500	900	23
Breeding		2 500 Pair with litter. For each additional breeding female add 1 000 cm2		23