My bordie collie is great he comes everywhere with my from work to holiday, he is 3 years old, by in large he is very well behaved, but he chases cars, bikes, people running horses etc I really dont know what to do about this and im really scared that he will get himself killed by a car, hes a really active dog and I dont want him to stay on a lead, when he gets it in his head this he is off nothing will stop him, im debating getting an e collar but am reading very negatives comments about them but I think if it will shock him our of it he will have a much better life and longer to Please help does your dog do this, can he change?????????????