Table 1.

Average ammonia levels and nasal pathology scores in mice housed in static cages

	Cage no.	Average ammonia level (ppm) on day 7	Average nasal pathology score	Individual nasal pathology scores	No. of pups in cage	No. of litters
Groups
BALB/c	1	126	1	1, 1, 1, 1, 1	NA	NA
	2	176	1	1, 1, 1, 1, 1	NA	NA
	3	238	1.4	1, 1, 1, 2, 2	NA	NA
C57Bl/6	4	27	0.6	0, 0, 1, 1, 1	NA	NA
	5	176	1.6	1, 1, 1, 2, 3	NA	NA
	6	400	2	1, 1, 2, 3, 3	NA	NA
Trios
BALB/c	7	168	1.3	0, 1, 3	6	2
	8	235	1.3	1, 1, 2	10	2
	9	350	2.7	2, 3, 3	4	1
C57Bl/6	10	23	0.3	0, 0, 1	0	0
	11	188	2	0, 3, 3	4	1
	12	256	2.5	2, 2.5, 3	10	2
Pairs
BALB/c	13	2	0.5	0, 1	1	1
	14	69	0.5	0, 1	5	1
	15	184	2.5	2, 3	6	1
C57Bl/6	16	26	1	0, 2	5	1
	17	40	1	0, 2	4	1
	18	70	1	1, 1	5	1

NA, not applicable.