Dog lover5678, sorry, but R has already been used.

-e i- your -rie--, your -art-er, your -e-e--er, your -o-. You are -i- -i-e, -i- -o-e, -i- -ea-er. -e -i-- -e your-, -ait--u- a-- true, to t-e -a-t -eat o- -i- -ea-t. You o-e it to -i- to -e -ort-y o- -u-- -e-otio-. ~ U---o--

Letters left to guess:
B C D F G H J K L M N P Q S V W X Z

Score:
3-greys-and-a-mutt: 20(E)+ 19(O)+ 13(R)=91
Rottie: 12(I)=24
Karen: 8(A)+ 13(T)=29
ShepherdLover: 10(U)+ 8(Y)=28