Dreaming about accidentally harming or killing a pet, like a bird, can evoke strong emotions and may reflect feelings of guilt, anxiety, or fear of losing something dear to you. Birds often symbolize freedom, creativity, and communication, so this dream might suggest concerns about your own sense of freedom or expression being stifled.

Consider the following interpretations:

1. Guilt or Regret: You may feel guilty about a situation in your life where you believe you've caused harm, even unintentionally. This could relate to relationships or responsibilities.
2. Fear of Loss: The dream might reflect an underlying fear of losing something or someone important to you. It could be a projection of your worries about your pet's health or well-being.
3. Change or Transition: Birds often symbolize transitions or changes. This dream could indicate that you're going through a significant change that you might feel unprepared for or fearful about.
4. Self-Expression: If the bird represented a part of yourself, this dream might suggest that you feel restricted in expressing your true thoughts or feelings.

Reflect on any current situations in your life that resonate with these themes. It may also be beneficial to address any feelings of guilt or anxiety you have in waking life to bring clarity and peace to your mind.