Firstly I do suffer from anxiety and had one of my dogs killed in similar circumstances.
I've had CBT therapy and discussed my anxiety around walking my small breed dogs because of other dogs attacking them and the incident where my pup was chased into the road.
I no longer take my dogs to parks but just do pavement walks which they are happy with as they never go off lead anyway (they have a garden to play in freely)
But there's a guy who has a massive black dog, like a mastiff or cane corso or something. And I always worry I will bump into him. Yesterday DH was outside and this guy passes and the dog lunges for a cat and come out of the guys hand. He just loses the lead completely and this huge dog is running up and down the road after this poor cat who climbs a tree.
Now I know that he doesn't have control of this dog and it chases small animals I'm scared to walk my dogs again :(
I know it's my mental health but it's also a real issue, there IS a large dog who chases small animals abou with an owner who can't control it.