1. Urinary system infection: Hematuria may be caused by urinary system infection, such as urinary tract infection or cystitis. These infections are usually caused by bacteria, which can cause inflammation of urethra and bladder, and then lead to hematuria.

2. Formation of stones or crystals: Female rabbits may have urinary stones or crystals, which will stimulate urethra and bladder and lead to hematuria.

3. Uterine diseases: The female rabbit may suffer from uterine diseases, such as metritis or uterine fibroids. These diseases can lead to inflammation of uterine tissue or tumor formation, and then cause hematuria.

4. Trauma or injury: The female rabbit may be injured or injured in the urethra or bladder area, such as urethral rupture or bladder injury, leading to hematuria.