Both calves and cows have a number of health risks around the time of calving. Of course, cattlemen and veterinarians recognize the risk to calves during and after a difficult birth; but is it also important to recognize that cows are at risk from several important complications following calving.
Lacerations – The reproductive tract can be torn during delivery, particularly if the calf is large or positioned incorrectly. Tears of the external reproductive tract occur when the vulva does not have time to stretch prior to delivery. Many times, if the tears are discovered quickly, they can be sewn together immediately. If a tear of the vulva is not discovered until it has started to swell, it is best to wait until all the inflammation is gone before correcting. Tears in the vaginal tissues are fairly common and it they don’t result in obvious bleeding may go unnoticed. There are some large blood vessels at the 2:00 and 10:00 positions of the vaginal birth canal, and if these are torn the situation can become an emergency. Occasionally a vaginal tear is identified when a mass of fat protrudes from the vulva. If a vaginal tear is discovered soon after calving, it can be corrected with a simple surgery. Because many vaginal tears are not detected soon after they occur, they may be first suspected when hard masses are palpated in the vaginal area during a rectal examination. Whether or not a vaginal tear leads to an infection or abscess that causes fertility problems depends on the size and location of the tear and the potential to correct the lesion.
Tears of the cervix and uterus are very difficult to treat and surgical repairs are rarely attempted. Tears in the uterus and cervix are usually due to improperly handled difficult calvings when excessive force is used to pull a large or malpositioned calf. The severity of a tear depends on how large it is and where it is located. In some situations the abdomen can become contaminated which can lead to severe illness or death.
Uterine Prolapse – A prolapsed uterus occurs when the uterus is pushed outside the abdomen after delivering a calf – leading to an emergency situation. Most uterine prolapses occur immediately after calving but it is possible for a prolapse to be delayed for up to several hours. Prolapse of the uterus is often associated with pulling a large calf. Cows that are in poor body condition or that are consuming a diet with mineral imbalances are at greater risk for this condition. A prolapsed uterus must be corrected as soon as possible in order to prevent severe bleeding and shock and to save the life of the cow.
Retained Placenta – The placental membranes are normally expelled within two to eight hours after birth. Occasionally, however, they fail to separate from the uterine attachments. Although retained placenta is rarely a life-threatening problem in cattle, it can lead to uterine infections and failure to become pregnant in the next breeding season. Not all reasons for retained placentas are known, but a herd with a more than an occasional retained placenta may have a disease or nutritional problem that should be investigated further.
There are differing opinions as to the best treatment for retained placentas. Research has shown that pulling on the placenta can cause more problems than it solves. For cows with a good appetite and no signs of abnormal vaginal discharge, it is probably best to continue to wait without treatment. Treatment with an injectable antibiotic is reasonable if a retained placenta leads to uterine infection.
Calving Paralysis – This condition is much more likely in heifers than in cows. The nerves that control the dam’s back legs can be damaged in a prolonged dystocia or if a calf becomes hip-locked. The condition may affect one or both rear legs. If the cow is down and the calf is hip-locked, the down leg is the one most commonly and severely affected. If paralysis is severe and affects both legs, the heifer or cow may not recover. If a cow is not able to rise and stand without assistance within 48 hours of calving, the likelihood of recovery starts to become doubtful. The chances for recovery after 2 to 3 weeks are very poor, and euthanasia may be recommended. The only treatments for calving paralysis are good nursing care and assisting the cow to stand several times a day through the use of a sling or hoist. The down cow should be kept in a well-bedded stall or pen, preferably with a sand or dirt floor.
Prevention strategies for all of these post-calving problems are focused on reducing the risk and severity of calving difficulty through: selection of appropriate calving ease bulls to breed to heifers, proper nutrition during late gestation, and effective and timely intervention when a birth does not proceed normally. When these post-calving complications do occur, you must work closely with your veterinarian to begin appropriate treatment to protect the health and life the affected heifers and cows.
