Failure of the uterus to return to its normal size following childbirth is known as subinvolution of placental sites. Involution of the uterus is the process by which the uterus contracts to its non-pregnant size after the delivery of the young. This usually takes 12-15 weeks to complete. Subinvolution, on the other hand, is the failure or delay in this normal process. It is a more common condition in younger female dogs and/or dogs that have experience their first litter. This condition is not a significant health problem.
There are no symptoms other than persistent postpartum vaginal discharge which provokes the owner to seek medical help.