If ur dog is too playful, ur dog might not show any sign of aggresiveness. The aggression is not to be wild but to protect you. There is nothing wrong to be playing with dogs. But too much of it affects them. overfeeding is another factor. The exposure of the dogs to everyone that comes around the dog will also contribute. This can be corrected in some ways
1) Start to chain the dog or to be locked up in the kennel
2) Try not to overfeed the dog
3) Do not allow people to play with the dog again.
If u can try these , u will see changes