Unlike dogs and cats, the female rabbit has a unique reproductive tract in that it lacks a uterine body and each of the uterine horns has its own cervix that opens directly into the vagina. There is abundant adipose tissue in the mesometrium and surrounding the ovaries, making identification and ligation of uterine vessels challenging for an ovariohysterectomy or Caesarean section.. Similar to cats and ferrets, rabbits are induced ovulators; however, ovulation occurs 10 h post-coitus in rabbits versus 30 h after copulation in cats and ferrets (2). Gestation ranges from 29 to 35 d, averaging between 30 to 32 d.
Dystocia is the inability to expel fetus(es) from the uterus during parturition and may be due to maternal or fetal conditions preventing a normal delivery. Maternal factors may include pelvic, vaginal, or uterine abnormalities, such as small pelvic size and uterine inertia, or may be due to malnutrition, parasitism, obesity, and/or hereditary causes. Fetal causes include malpresentation, malposition, or malposture, oversize, fetal death, or malformations, such as fetal monsters. In many species, uterine inertia is the most common maternal cause of dystocia, and may be considered either primary or secondary. Primary uterine inertia can be defined as gestation beyond its expected length with no progression into stage 2 labor. It may be associated with hypocalcemia, obesity, overstretching of the myometrium from large litters, and conversely, inadequate uterine stimulation from small litters . Primary uterine inertia occurs less commonly than secondary uterine inertia . Secondary uterine inertia, or uterine fatigue, occurs due to exhaustion and lack of myometrial contraction after prolonged attempts to expel an obstructed fetus, which persists following the relief of the obstruction (6,8). Dystocia is not common in rabbits as normal delivery is typically completed within 30 min after onset. Common causes of dystocia in rabbits include obesity, oversized kits, a narrow pelvic canal, or uterine inertia. Indications of dystocia in rabbits include persistent contractions, straining, and bloody or greenish-brown vaginal discharge. However, as obstetrical problems are rare in rabbits and parturition is very quick with minimal physical exertion, any indication of labor can be interpreted as a sign of dystocia.