In San Diego we have leash laws and if you are caught on a public street or park etc. with your dog off leash you can end up paying a hefty fine. Although it may appear that the purpose of the leash laws is to create additional revenue for the local government, which is probably true, that is not the most important reason we have these laws.
The laws were created to protect people and other animals, as well as the pooch off leash. You may have an extremely well-behaved dog who never leaves your side, however, there are dogs out there that react very aggressively when approached by a dog not on a leash. Your dog may have the best intentions of being friendly and playful, but that doesn't work for other dogs who may misread the approach and the body language.You could end up with your dog getting bitten, mauled or traumatized.
Yesterday while I was out doing my regular dog walking with a sweet female dog who gets along well with other dogs, I saw a dog jump out of a car and dash across the street to greet my dog. Fortunately, the dog I was walking was friendly. Also, fortunately, there were no cars coming but I can assure you if a car had been on the street, that dog would have been killed.
While walking another dog on a public bike and walking path, two off-leash beagle dachshund mixes ran over to say hello. They were not friendly towards my dog and had to be restrained by the owner. Again, fortunately, nothing bad happened but it was stressful and traumatizing for both me and the dog I was caring for. In another instance I saw a dog walking off leash, sniffing away looking for a place to go on the grass. Her owner was walking in the opposite direction looking at his Iphone and not paying any attention to his dog at all. I called to him and told him to watch his dog. He smiled and said he was. Then he turned towards her and called her name. I don't know what would have happened if I wasn't there to call his attention to his dog.
PLEASE, follow the leash laws and keep your dogs on leash except in your own fenced in yard. I really don't want to see something bad happen, to the dogs in my care, or to your dogs.