Dreams involving pets, especially those we are closely attached to, can evoke strong emotions. Your dream about your dog jumping over a fence and injuring itself may symbolize several things:

1. Concern for Well-being: This dream could reflect your worries about your dog's safety or health. It might indicate that you are feeling protective or anxious about something in your life that you feel is at risk.
2. Boundaries and Freedom: The image of your dog jumping over a fence can represent a struggle between wanting freedom and the risks that come with it. It may suggest that you or someone close to you is attempting to break free from constraints, but there are potential consequences to that action.
3. Vulnerability: The graphic nature of your dog's injury could reflect feelings of vulnerability or helplessness in your life. It might indicate that you are feeling exposed in some area, whether emotionally or physically.
4. Change or Transition: Such dreams can also signify a transition or a significant change in your life that feels painful or difficult, akin to the injury suffered by your dog.

Reflect on your current life circumstances and emotions to gain deeper insights into what this dream might mean for you. If you’re feeling particularly anxious or concerned, consider reaching out to someone for support or to talk about any worries you may have.