Birth is a normal biological process. It does not require management as a disease, but even a seemingly “uneventful” birth is stressful and traumatic for the mother and neonates.
Occasionally during the birth process, the pup may suffer a physical injury. This is called birth trauma or birth injury. It includes any injury affecting the infant during labor and/or delivery.
Fortunately, studies have shown that neonates recover from injury faster than adult rats.
*Note: Prior to labor, the history of trauma to the mother is of importance as this can affect the unborn babies.
During physical examination of a pregnant rat it is important not to press hard on the abdominal area. This can cause injury to the fetuses resulting in a birth defect, injuries in utero, and even death.
Causes and Effects of Birth Injuries
Normal Birth & Injury
Normal birth processes such as muscle contractions during labor, passing down the uterine horn, moving through the cervix and birth canal, and exiting through the vaginal opening can cause injuries. These birth injuries are often minor event that heal quickly, although when severe they can result in permanent damage and even death.
Size of Pup
A larger pup may have a hard time passing through the birth canal or may get “hung up” passing from a uterine horn to the birth canal. A small pup may get wedged in between larger babies. Its body may be slightly more fragile and prone to injury and bruising.
Birth trauma can occur when the flow of blood (and thus oxygen) is restricted during birth. This can occur from events such as (but not limited to) compression, blockage, or umbilical cord restriction.
During an obstructed birth the pup becomes lodged either moving into the cervix or in the birth canal. A lodged pup will sometimes naturally become dislodged and birth will continue normally and uneventfully. A severely lodged pup that cannot pass through the canal will eventually die, as will the babies behind it. a pup lodged in birth canal pulled out by its mother may suffer birth injuries. This includes: bites, contusions, bruising, missing limbs, or a severed tail (partial or complete).
A long labor can exacerbate other issues and make birth injuries worse. It can cause the oxygen supply for the babies to be limited or even diminished.
Intense labor creates extra physical stress on the babies from repeated muscle contractions while they are already confined in a tightly restricted space.
During a difficult birth the mother may assist in the birth by pulling at the pup with her teeth. This may occur particularly if the pup is stuck. Unfortunately this can cause bite wounds and even amputation of limbs or tails.
Mothers may also accidentally wound offspring during initial cleaning while they are removing, and ingesting, the birth sac and placenta.
Compression injuries can occur either during delivery or labor and can range from minimal to severe. They are a result of external pressure.
Severe Birth Trauma
At times birth injuries can be very serious. Bones can be fractured, limbs can be dislocated, or internal bleeding may occur. Development of the neonate can be impaired from lack of oxygen.
The most severe birth trauma will end in death.
Birth Trauma Photos and Case Histories
- Fig. 1: Maternal bites
- Fig. 2: Cranial compression injury
- Fig. 3: Pup lodged in birth canal (From “Labor Emergencies- Figure 1)
- Fig. 4: Feet amputated by Mother
Treatment and Nursing care
Treatment, intervention, and nursing care of birth injuries should be determined on a case by case basis. With some injuries it is best to leave the pup alone with its mother and let her care for it.
There are other cases when veterinary treatment is essential, wound care is needed, or nutritional supplementation is required. In certain situations, where the outcome is terminal, there is suffering, or there are quality of life issues it may be more humane to euthanize the pup. Your veterinarian can help you to determine what level of treatment, if any, is appropriate for the injured pup.
The first step of any intervention is to be able to check or treat the pup without stressing the mother out. Sometimes a new mother rat will tolerate a known owner handling their babies for a short period of time. But some will not. It is better to assume that a mother rat my bite until you have established trust. And even then it is wise to be careful.
Odors are another important consideration. For the most part mothers will not abandon or harm their babies after they have been touched, but it can happen. When treating a pup try to keep any odors to a minimum or take appropriate measures to use methods to downplay the odors, (This will be addressed below in “Supplementing Safely” and “First Aid for Birth Injuries.”).
Females that are with new owners, came pregnant from a pet store, are rescues, or that have shown previous aggression may require using certain tactics to access the babies. One method is to simply lure the mother out of the cage or to another portion of the cage with food. Another method, if using a bin or aquarium, is to use cardboard to create a temporary barrier between her and her babies.
Babies thrive better if they are left in the nest with their mother and their siblings. It may, however, be necessary to give them supplemental feedings at least once a day if they are not thriving. This is also sometimes done with extremely tiny babies (runts).
Because the mother rat uses her sense of smell to identify babies it is important to make sure, at least in the beginning, to not send a pup you have hand fed back to the nest reeking of formula. Not only is it a matter of her identifying the pup as something not from her nest, she may also recognize it as food and take a nip before she realizes her mistake. Usually they will simply lick the formula off the pup, but accidents do happen so it is better to be safe than sorry.
After a supplemental feeding wipe the pup down. Also, make a small dish of formula and give it to the mother before returning the pup to the nest. It will help her to trust you and also mask any formula smell on the pup.
First Aid for Birth Injuries
Generally the only first aid for babies will be wound care. Use a sterile saline solution on open wounds to clean them. Pat the areas dry an apply a small amount of antibiotic ointment once or twice a day as recommended by your veterinarian.
You can dab some ointment on mom’s nose, the top of her front paws, or on her chin. This may fool her into thinking the ointment is on her rather than on the pup, which may help keep her from licking it off the wounds.
It is not often that birth injuries will require medication such as antibiotics. If the vet deems that medication is appropriate, be sure it is not one that may cause the pup more harm than good.