yes spaywill help some but i think you also need to consider the breed. if it is a terrier mix you have to realize that terriers are not always friendly with other animals esp dogs.

look at the excerpts from the akc page

on terriers in general . . .

Terriers typically have little tolerance for other animals, including other dogs.

sometimes the temperament requirements in the standard reflect dog-dog aggression in a breed.

scottish terrier . . .

The Scottish Terrier, while loving and gentle with people, can be aggressive with other dogs.


some of this aggression may be hard wired. i would suggest treating the terrier when she is behaving around the other dog. pet the other dog treat the terrier if she behaves.