Down Cow After Calving
History. A 4-year-old Jersey cow calved earlier this morning; this was her second calf. The producer called you because the cow stood after calving but appeared uncoordinated. Now, a few hours later, the cow is just recumbent and appears dull.
She has been offered water and hay but has not accepted either. No other cows are affected. This cow has no history of medical problems.Clinical Examination. The cow appears dull and does not pay much attention to you or the other activity in the barn. Fhe cow’s temperature is slightly low, and her heart rate is slightly increased. Her respirations are normal. She is slightly dehydrated. Her ears are cool to the touch, peripheral pulses are weak, and her rumen contractions are decreased. On examination, she does not appear to have any injuries that would prevent her from standing. Your brief neurological examination is normal, but the cow does have an S-shaped curve to her spine.
Comment. This cow most likely has hypocalcemia. Because of the high demands for calcium in the development of the calf in late pregnancy, combined with the production of colostrum and milk, this cow has become hypocalcemic. As reviewed in this chapter, calcium is critical for muscle contractions. Calcium also assists with membrane stabilization of peripheral nerves. Deficits can cause mild tetany, which is sometimes seen in cows with hypocalcemia. Additionally, the release of acetylcholine (ACh) at the neuromuscular junctions is mediated by calcium. Hypocalcemia causes decreased ACh release, which can cause paralysis. All the clinical signs— hypothermia, increased heart rale, weak pulses, paresis, cool extremities, S-shaped curve of the spine, and decreased rumen contractions—can be attributed to hypocalcemia. A definitive diagnosis can be made by measuring ionized calcium. However, most veterinarians and producers will treat based on clinical signs, with the diagnosis confirmed based on response to treatment.
Treatment. Cows are treated with calcium gluconate, which is slowly given intravenously. Most cows will show improvement in clinical signs during the treatment. Cows often become brighter, their rumen contractility and peripheral circulation improve, and their core body temperature normalizes. Most cows attempt Io stand after treatment, which is usually about 1 g per IOO pounds. Some cows will relapse and will need to be re-treated.