The peripartum period — late gestation, parturition, and early lactation — is a stressful time for a beef cow. She is at high risk for metabolic disorders, but also gastrointestinal and infectious diseases. The key is to expect them and be ready to act, but hopefully try to prevent them.
Dr. David Van Metre from Colorado State University spoke on several peripartum diseases at the North American Veterinary Conference. He presented two cases to illustrate the challenge with these disorders. Both reflect the importance of proper feeding.
The first case involves a seven-year-old Angus cow in her last month of pregnancy. She was presented to the Veterinary Teaching Hospital (VTH) at Kansas State University after a week of bloating, poor appetite, and production of scant feces. The owner gave polaxelene and magnesium hydroxide, and passed a stomach tube, all to no benefit.
When examined by the clinicians at the VTH, the cow’s heart rate was elevated (90 beats per minute), her respirations shallow, and she was mildly dehydrated. She appeared weak, lethargic, and her abdomen was distended with swellings on the upper left and lower right sides (called pappleshaped). Her rumen was barely moving. Her fetus could be felt through the right flank. On rectal examination, she seemed to have a viable, late-term pregnancy.
Based on this examination, the attending clinicians believed that the cow had a functional or physical obstruction of the upper gastrointestinal tract (GIT). They thought she may have vagal indigestion secondary to hardware disease, lymphosarcoma, or liver abscesses. But, she also could have been suffering from many other intestinal ailments.
Because they could not pin down a disease, this led to uncertainty in her prognosis. The owner allowed the clinicians to investigate more. Unfortunately, although the blood tests ruled out an infection, they could only confi rm that there was a problem in the upper GIT.
Based on the cow’s questionable future, the owner consented to induction of parturition and a cesarean section. Medications were given, but the next morning, the cow was unable to get up. A caesarean was immediately performed to deliver a live 89-pound heifer calf.
During surgery, the abdomen was explored and the sole abnormal finding was hepatic lipidosis (fat buildup in the liver due to insufficient caloric intake). The cow deteriorated over the next 24 hours and was euthanized. Postmortem examination confirmed severe hepatic lipidosis.
This case highlights the perils of a negative energy balance where the cow can’t eat enough to meet her needs. But, what put her in this situation?
Indigestion in late pregnancy is uncommon, but lack of appetite, rumen distension, and scant fecal output support this possibility. Indigestion may occur if the stomach fails to empty, which can be due to the pregnancy itself. The huge calf-filled uterus could physically impair the emptying of the abomasum. Then, poor rumen motility could have triggered the mild gas bloat. The only way to pin down indigestion of this type is by seeing a positive response to either parturition or a planned caesarean. If normal GIT function fails to return, it implies something else is going on.
Hepatic lipidosis is a reflection of a negative energy balance. Again, this is difficult to diagnose except by seeing it at surgery or via post-mortem. In this case, hepatic lipidosis was confirmed, but it had gone too far and the cow was too ill to recover.
The second case was a five-year-old Angus-cross cow. The cow was lying down (recumbent) and unable to stand for two days. The cow calved a week
previously and her calf was alive and healthy.
The owner also reported that another three cows had become “downers” in the last two weeks. A three-year-old calved normally, went down, and died three days later. The other two, a five-and seven-year-old, had each gone down a day after normal calvings. The cows showed no evidence of ataxia. One was euthanized on the farm after seven days being down. No post-mortem had been done.
The downers were alert and they could crawl, but they had extreme difficulty rising. Body condition and appetite were poor. The feed consisted of grazing corn aftermath (stalks) and native grass hay. The producer had tried different treatments (propylene glycol, flunixin meglumine, oxytetracycline, calcium/dextrose solutions, and dexamethasone) but there was no positive effect.
The presented cow had a BCS of 2 (very thin) on a scale of 1 to 9. The other three cows in the herd that became downers had similar body condition scores.
When approached, she stood, but was short-strided with apparent muscle tremors. Her heart rate was elevated. On rectal examination, the uterus was normal for her stage of lactation.
The cow was moved to an outdoor pen and immediately began to eat. She stood for about an hour and demonstrated no lameness as she was slowly moved in the pen.
The clinicians suspected that nutrition was the cause of the weakness. However, the owner wanted to rule out other causes before settling on improper feeding as the issue. The clinicians’ reasoning on how they eliminated other diseases and how they came to their conclusions serves as a way to diagnose any cow that has gone down.
The first thing to consider with a downer cow is a myopathy (muscle disease) that causes weakness. These include white muscle disease, toxins (ionophores), trauma, infections, and others. Blood tests can help pin these down.
Peripartum cattle can also suffer from electrolyte imbalances. This can include hypocalcemia, hypomagnesemia, hypokalemia, and hypophosphatemia. All of these, singly or together, can cause weakness.
Low calcium could be expected in a cow after calving due to calcium going to the fetal skeleton during pregnancy and then to the milk in lactation. Hypocalcemia causes poor muscle contractions.
Low phosphorus, again due to mineral surging to the calf, can also trigger weakness. This is often accompanied by low magnesium, which in itself, can cause low calcium levels.
The low potassium (hypokalemia) is commonly associated with low feed intake. The mineral is plentiful in forages and, if the animal is eating, it does not need supplementing.
Hypoglycemia (low blood sugar) coupled with ketosis and hepatic lipidosis due to a prolonged negative energy balance should be considered, especially in a thin animal.
If multiple animals have generalized weakness, botulism (food poisoning) can be considered. However, affected cattle have characteristic weakness of the neck muscles and poor function in the cranial nerves that supply the head.
If the pelvic nerves become damaged during passage of the calf, the cow’s back legs may fail to work. If this was the case, it should have been apparent immediately after calving, not a few days later. As well, if an infection and/ or septicemia was present, this should have been picked up on a physical examination. This cow had no findings to support this.
Blood tests were done on the cow to look for a cause of the weakness. All of the electrolytes mentioned above (calcium, magnesium, potassium, and phosphorus) were low. There was no indication of a muscle problem, infection, nor any other disease.
The combination of electrolyte abnormalities contributed to the clinical weakness. To correct these deficiencies, the clinicians recommended an oral solution containing calcium, phosphorus, magnesium, and an energy source.
When the blood tests results were provided to the producer, he then had hard evidence that implicated poor feeding. It convinced the producer that a thorough review of his cows’ nutrition was needed. Meetings were arranged between beef extension specialists and the producer.
Both of these cases illustrate how important nutrition is in the peripartum cow, both before and after calving. But, it is not the only cause of problems. If a cow becomes ill during this time in her reproductive cycle, a veterinary examination can help determine the cow’s prognosis and her future in the herd.