That was a dig by the way
To the OP, another thought has occured. Your dog might have a heart conditition, if he has then that could be why he's aggressive.
You should take him to the vet for an examination, and if you can afford, let him have an ECG.
If it does turn out he has a heart condition then they will put him on tablets for the long term future, and you will not be able to let him off the lead for his own benefit.
There's a woman I often see in the park, she has a lot of dogs and only one's on the lead, that one dog has a heart condition and is on tablets, he's never let off the lead.
On the other hand, I always see a young couple with a young dog, it looks like a collie. They have it on a long lead and they throw balls for it, when it runs after the ball, the lead extends to its maximum length nearly strangling the dog. Poor thing, why don't they just let him off the lead for once?
