Hi Tim,
Here is the correction for one of the sentences :
The dogs in cilazapril and valsartan groups were given cilazapril (1mg·kg-1·d-1) and valsartan(30mg·kg-1·d-1) respectively from 1 week before pacing till the pacing was stopped.
if this is what you want to say :
cilazapril group ---> cilazapril (1mg·kg-1·d-1)
valsartan group ---> valsartan(30mg·kg-1·d-1)
for a period starting one week before the start of pacing till the end of pacing.
Otherwise, the abstract looks fine.