My 8 year old mixed breed has issues with gun fire in the woods and thunder. She had a fight with our 7 year old Coon Dog. She was out of sorts because we had a friend visiting with a smaller dog, staying with us for several weeks and it wanted a lot of attention. I took her to the vet for her annual and told her of the dog fight. She prescribed Zylkene and within a couple doses our house guest noticed a change in her demeanor.