Milk fever (Hypocalcaemia)
Milk fever occurs when blood calcium (Ca) concentration becomes too low to support the functions of the nerve cells and the contractions of muscle tissue. Milk fever (Parturient paresis) is an acute, flaccid paralysis of mature dairy cows that occurs most commonly at or soon after parturition.
At or near the time of parturition, the onset of lactation results in the sudden loss of calcium into colostrum and milk. Serum calcium levels decline from a normal of 8.5–10 mg/dL to 2–7 mg/dL. Commonly, serum phosphorus is decreased, and cows are hyperglycaemic. The disease may be seen in cows of any age but is most common in high-producing dairy cows entering their third or greater lactation. Incidence is higher in the Jersey breed. Milk fever usually occurs within 72 hr of parturition. The disease can contribute to dystocia, uterine prolapse, retained foetal membranes, metritis, abomasal displacement, and mastitis.
Treatment is directed toward restoring normal serum calcium levels as soon as possible to avoid muscle and nerve damage. This can be carried out several ways e.g. intravenously or orally.