Deborah Fowler, 59, lives with Fibromyalgia and often has her grandson take her two dogs out for their walks around the East Lothian town.
She explained: “My 12 year old grandson Daniel was walking my dogs in Port Seton by the High Street, this is something he does everyday – he loves the dogs.
"On his way home, four teenagers thought it would be funny to pick up a ginger cat and throw it on one of my dogs.
"Lucky my dogs are non aggressive because the cat landed on one of their backs.
"This gave my grandson a fright, he is a tall boy but it still scared him, he shouted at them and they thought this was highly amusing.
"A gentleman also shouted at them. I was so angry as not only my grandson, but my dogs or the cat could have been severely hurt.”
Deborah was shocked as she found out from her grandson what had happened, adding: My grandson will now not walk my dogs, it really shook him up.”
Inspector Stuart Fletcher commented: “We are acutely aware of the adverse impact that anti-social behaviour has on our local communities.
"We continue to work closely with our partners as part of a Problem Solving Partnership in these areas to tackle this issue and take action against those responsible.
"I would encourage residents to report any incidents to us on 101.”