Take the mouse to an emergency vet and have them use CO2 to put the mouse to sleep.
1	Take	take	VERB	VB	Mood=Imp|VerbForm=Fin	0	root	0:root	_
2	the	the	DET	DT	Definite=Def|PronType=Art	3	det	3:det	_
3	mouse	mouse	NOUN	NN	Number=Sing	1	obj	1:obj	_
4	to	to	ADP	IN	_	7	case	7:case	_
5	an	a	DET	DT	Definite=Ind|PronType=Art	7	det	7:det	_
6	emergency	emergency	NOUN	NN	Number=Sing	7	compound	7:compound	_
7	vet	vet	NOUN	NN	Number=Sing	1	obl	1:obl:to	_
8	and	and	CCONJ	CC	_	9	cc	9:cc	_
9	have	have	VERB	VB	Mood=Imp|VerbForm=Fin	1	conj	1:conj:and	_
10	them	they	PRON	PRP	Case=Acc|Number=Plur|Person=3|PronType=Prs	9	obj	9:obj|11:nsubj:xsubj	_
11	use	use	VERB	VB	VerbForm=Inf	9	xcomp	9:xcomp	_
12	CO2	CO2	NOUN	NN	Number=Sing	11	obj	11:obj	_
13	to	to	PART	TO	_	14	mark	14:mark	_
14	put	put	VERB	VB	VerbForm=Inf	11	advcl	11:advcl:to	_
15	the	the	DET	DT	Definite=Def|PronType=Art	16	det	16:det	_
16	mouse	mouse	NOUN	NN	Number=Sing	14	obj	14:obj	_
17	to	to	ADP	IN	_	18	case	18:case	_
18	sleep	sleep	NOUN	NN	Number=Sing	14	obl	14:obl:to	SpaceAfter=No
19	.	.	PUNCT	.	_	1	punct	1:punct	_
