Dogs are social beings, bur many humans see it only during play time: if the dogs are playing with each other there is social contact, if they are not – there is not. This simply is not true. Whether it will be keen on playing with other dogs depends on its age, temper and traits. You and your dog are a pack, not you, your dog and other owners with their dogs in a park. While you walk with your dog and another owner and its dog are approaching you: it is a meeting of two packs that can end with quick sniffing, passing by, playing or conflict.
Parks
A dog does not care if it is an official dog park or a plain with five, ten or twenty dogs in it, with immobile owners. Those type of circumstances usually bring out territoriality and an urge to establish hierarchy, especially with dominant dogs. This usually turns into quarrels or fights, particularly if there are two males and one female in the park. Dog parks provide some running around and fun time with other dogs, but cannot replace the walk.
They are mainly useful for dogs with behavioural problems such as aggressiveness, timidness, proneness to run away... this is the only time they can get to be off the leash. That way, they can run, and owners as well as others on the other side of the fence can feel safe. They are important for cubs and very young dogs, since the urge to migrate is not developed as much. The urge to play is bigger, and urge to establish hierarchy smaller.
Most common causes of fights in dog parks:
1. Three or more dogs that are not close.
2. Presence of at least two dominant dogs.
3. Bringing the food into the park.
4. Presence of excited dog will either tease or make other dogs stay away which will bring out predatory instincts in it. They will be prone to attacking timid dogs.