You may be tempted to interact with a service dog, BUT before doing so be aware of the proper protocol.
Service dogs have years of training behind them and a serious job.
Proper Protocol Around Service Dogs:
1. Service dogs should not be touched without permission, or offered treats or food.
2. Do not whistle of make distracting sounds.
3. If you would like to speak, speak to the person and not the service dog.
4. When you are walking your dog and come across an assistance dog, remember that the assistance dog is not a pet dog ready to play and that your dog may be disruptive to the team.
5. If you are unsure whether your dog will remain under close control when passing a service dog, you may be wise to cross away from the service dog to limit distraction.
Stopping to say hello and letting your dog sniff or play with a service dog is NOT appropriate, unless the dog has been give a "Release" command.