How to Choose and Administer an Oral Electrolyte
December 19, 2019
Robert B. Corbett DVM, PAS
The most common calfhood disease is diarrhea. Most individuals responsible for treating sick calves understand the importance of rehydrating the calf and are generally familiar with oral electrolyte solutions.
However, choosing which oral electrolyte to use is often based on price or the recommendation of an animal health professional. In times of tight margins, most operations opt to use less expensive products. It is common for the larger operations to purchase their oral electrolyte product in bulk to reduce the cost per treatment. While bulk products usually contain a scoop to deliver the exact dose for one treatment, it’s not uncommon to dish up a heaping scoop or operate under the premise if a little bit is good, a lot would be better.
When choosing among electrolyte products, most assume all are created equal, so it comes down to price. The ingredients in electrolytes are often expressed in different ways, making it next to impossible to read the labels and compare products. Most veterinarians have not been trained on correct formulation of electrolyte products so they are not able to advise their clients on the best product for their calves.
A well-formulated oral electrolyte solution includes:
-Sodium Concentration: 90 to 130 mmol/L
-Chloride: 40 to 80 mEq/L
-Potassium: 10 to 30 mmol/L
-Osmolality: 500 to 600 mOsm/L
-Strong Ion Difference: 60 to 80 mEq/L
-One or more alkalizing agents: bicarbonate, acetate, propionate
-Glucose: 2 to 3 grams per kg body of the calf
-Glucose, neutral amino acids and volatile fatty acids to facilitate sodium absorption
Paired With Milk
Ideally, administration of oral electrolytes should be spaced evenly between milk feedings to gain the maximum benefit of rehydration. This is often difficult to achieve because milk feedings are usually less than 8 hours apart so that one shift of employees can handle both feedings. This results in periods of more than 16 hours before the next morning feeding. The ideal situation would be to feed two feedings of oral electrolyte solution between the two milk feedings and after the last feeding as far apart as possible.
Don’t mix the oral electrolyte solution with milk or milk replacer. It will increase the osmolarity of the combination, likely resulting in an extremely hypertonic solution that could exacerbate the diarrhea problem. If the electrolyte solution must be fed close to the milk feeding, reduce the milk replacer to 12% or 12.5% solids to prevent a hypertonic environment in the intestine.
Common Mistakes to Avoid
When treating calf diarrhea, don’t discontinue feeding milk. Milk is the major source of nutrients for the calf. If treated correctly, most calves should be able to maintain a positive weight gain during a bout with diarrhea.
In general, unless the calf has an elevated temperature, oral and systemic antibiotics are not advised. Antibiotics will have a significant negative effect on the microbiota of the gastrointestinal tract, which is important to maintaining the mucin layer of the gut lining, the gut-associated immune system, the competitive inhibition of pathogens and digestion of nutrients passing into the small intestine.
Most of the information on the electrolyte formulation is taken from Dr. Geoff Smith’s chapter in “Veterinary Clinics of North America,” 2008. He says oral electrolyte solutions should supply sufficient sodium to normalize the extracellular fluid volume, provide agents that facilitate absorption of sodium and water from the intestine, correct the metabolic acidosis usually present in calves with diarrhea and provide energy. The oral electrolyte should not cause any harmful effects, such as abomasal bloat.