I have read your question and your question is whether a wound from a dog will heal on its own. The most important thing about wounds is that they are clean. Cleansing the wound with soap and water will help clean particulate material from the wound. The nest thing is to use bandages called steri-strips to bring the edges of the wound together. This would be things that you could do to reduce infection and aid healing. My next concern for you is you immunization status. When was the last time you had a tetanus booster. If it has been more than 10 years then I would have you get a booster shot. The next concern is the dog up to date on its immunization for rabies. If this was a stray dog then I would recommend seeing a doctor for rabies immunizations. Hope this answers your question. If you have any further questions please contact us again