If you have damage done they should have to pay for it. This happened about 5 years ago to my parents, the neighbors about 1/2 mile down the road had their cattle get out and we found them in my parents yard one day. They had a really big above ground pool and a nice big deck that wrapped around 1/2 the pool, the cows trashed the deck and pool and alot of small trees we planted in the yard, they covered all the damage done. Good luck and hopefully it wasn't too bad.