catch him yourself or call the dog shelter?
If you'd prefer not to try this, you can get in touch with the nearest animal shelter. Give them your exact location and try to keep an eye on the dog until they arrive. Give them your cell phone number in case they have trouble finding you. Later, you may want to contact the shelter and find out how the dog is going or maybe even call in to see him.
If you decide to catch the dog, it is important to stay calm. Watch out for signs of anxiety which could lead to aggression or the dog running away from you. Try not to make direct eye contact with the dog. It is likely that the dog will be quite frightened. Be careful not to make the situation worse with your own actions. Avoid shouting at the dog or running after him. Give her chance to work out that it is not your intention to harm him and that you are someone he can trust.
get the stray dog away from any immediate danger
Your first objective should be to get him away from any immediate danger. If necessary, move him from a busy traffic area to a quieter one. If you can, get him into a fenced yard. This will give him an opportunity to rest and calm down. Offer him some food and water and back off for a while. It is important that he does not feel trapped. Hopefully, after a time he will trust you enough to get closer. Be aware of your own safety at all times. Any sudden movement on your part could scare her and lead to a bite. Talk to her in a soothing voice and take hold of her collar or even the scruff of her neck.
make every attempt to contact the owner
Do everything you can to locate the owner. It may be that the dog has just become temporarily separated. Look for a collar tag. If you decide to hand the dog in at a shelter, they will be able to check if the dog has been microchipped.

