[Acid-base and potassium balance disorders in neonatal calf diarrhea - Part 2: Therapy and prognosis]

Neonatal diarrhea in calves frequently results in severe metabolic disturbances, particularly D-lactic acidosis and hyperkalemia. These conditions are associated with weakness, apathy, and, in the case of D-lactic acidosis, with neurological deficits such as impairment of the palpebral reflex. Severe hyperkalemia can be accompanied by potentially life-threatening cardiac conduction abnormalities. The second part of this review article provides a narrative overview of therapeutic approaches as well as the prognostic relevance of these key metabolic disorders.

Correction of metabolic acidosis is of crucial importance in the treatment of calves with neonatal diarrhea. Oral rehydration by administration of buffer-containing electrolyte solutions represents the simplest and most cost-effective therapeutic option in calves that are still able to drink. For intravenous correction of metabolic acidosis, sodium bicarbonate is the treatment of choice. Appropriate therapeutic decisions can be made under field conditions by assessing the calf's ability to stand, the clinical degree of dehydration, and the degree of loss of the palpebral reflex. If enophthalmos (eyeball recession of 3-4 mm) or signs of metabolic acidosis (impaired ability to stand or absence of the palpebral reflex) are present, intravenous fluid therapy is indicated. Rapid infusion of small-volume hypertonic sodium bicarbonate solutions in combination with oral administration of electrolyte solutions is particularly suitable for calves with clinical signs of acidosis but without enophthalmos. In calves with enophthalmos, the infusion of a larger volume of isotonic crystalloid solutions is recommended. Initial intravenous administration of hypertonic sodium-containing solutions also offers advantages for the stabilization of calves with clinical signs of hyperkalemia, as this may rapidly reverse the cardiotoxic effects.

Laboratory parameters are generally of limited prognostic value in calves with neonatal diarrhea. Even in cases of marked metabolic alterations, treatment attempts can be worthwhile as long as no severe concurrent or secondary problems are present.