Rt48

[hope3fully]

2d dog cage placed over hydrant 5 -o-c-pooch 14d behind sierra,ran amok 2,7 on,-r- - - - p 21a weight that is most comprehensive 6 -i- - -t 23a in-house, a rival brand 4 -e- - semi

[Mamyalynne]

2 Coop , back + H (hydrant) - Pooch - Dog

[Lie-in King]

2d Yes - Pooch - 'coop' (cage, over) + 'h(ydrant)'
14d In arrears - anag 'Sierra ran'
21a Widest - 'w(eight)' + 'id est' (ie; that is)
23a "...hou SE A R ival..." (brand)

[hope3fully]

many thanks