Susan,  I can't really tell for sure what type of bush you have from the photo of sent.  However it does look like it could be a large boxwood.  Take some leaves of the offending bush and crush them.  If more of the offensive odor is released you have your culprit.  I  found some mention of  boxwood varieties that do release an odor smelling similar to cat urine at certain times of the year.  If it is your shrub then removal is the way to get rid of the smell.