10/23 - Electrolytes

Hypocalcemia

What electrolyte abnormality is also called milk fever and often occurs at parturition in cows, SRs, and pigs, especially in dystocia, non-dilated cervices, and weak contraction cases? It can also occur in late gestation SRs with multiple fetuses, presenting as weakness, recumbency, and ketosis. There will be decreased muscle activity, muscle weakness, dystocia, prolapse, dry nose, decreased GIT activity, and slight tachycardia. Risk factors include cows, high BCS, high-production, multiparous, metabolic alkalosis, poor nutrition, hypomagnesemia, and multiparous SRs. Treatment is with IV Ca products while monitoring heart rate and rhythm. Prevention is with DCAD diets to create a mild metabolic acidosis during the most prone periods.

Hypomagnesemia

What electrolyte abnormality can predispose to hypocalcemia and can occur due to toxic mastitis, trauma, and botulism? Some cases are subclinical. It is usually a beef cow problem, and can present with grass tetany or grass staggers. This ion is a cofactor in every major metabolic pathway, nerve conduction, muscle function, and bone formation. Concurrent hypocalcemia can also contribute to this. Risk factors include lactation, anorexia, transport, lush pasture with high K/nitrogen, and poor quality winter forage. There are often no clinical signs until less than 1.1 mg/dL and then there is progressive onset, twitches, frenzied/goosestep gait, lateral recumbency, and death. Tachycardia, tachypnea, and fever can all occur. Diagnosis is with history and CS, plus vitreous humor measurements of this ion postmortem. Treatment is with slow IV administration of Ca and Mg (Norcalciphos) in a low stress environment but relapses are common. It can then be supplemented PO. After treatment, move off pasture, monitor for recurrence, and treat the entire herd with better feed, Mg boluses, and Mg mineral blocks or salts.

Hypophosphatemia

What electrolyte abnormality is required by animal and rumen microbes and is mostly intracellular in bones? It is taken up in the GIT and excreted through saliva, milk, and urine. Signs include anorexia (most common), rickets in juvenile camelids, unthrifty or stunted growth, pica, reduced fertility, muscle weakness, recumbency, and IV hemolysis postparturient. The rickets form is associated with vitamin D deficiency, especially in camelids and occurs in animals born in late fall or a cloudy summer, and in high latitude areas with reduced sun exposure. You should measure P and vitamin D, plus radiographs to diagnose (ALD, physeal flaring, costochondral junction flaring). Treatment in adult cows is with oral supplementation but IV treatment is also possible. In camelids you can give injectable vitamin D supplements SC for 60 days, but overdoses are important to monitor for.

Hypokalemia

Which electrolyte abnormality occurs due to anorexia, isoflupredone acetate administration, metabolic alkalosis, prolonged IV fluids without supplementation, diuretics, and insulin? Signs include weakness, recumbency, tachycardia, and depression. Treatment is with fixing the primary problem, transfaunation or otherwise getting them eating, and supplementation PO. Prevention is with ketosis treatment and appropriate IV fluids.