Oral rehydration solutions help replenish fluids and electrolytes lost during the course of diarrhea.

According to “Electrolytes for Dairy Calves” by Sylvia Kehoe, University of Wisconsin-River Falls, and Jud Heinrichs, of Penn State University, these solutions are designed to improve the acid-base balance by providing electrolytes and water. Although easy to use, neonatal calf diarrhea is still a major cause of death.

There are two main types of scouring in neonatal calves — nutritional and pathogenic. Nutritional scours are caused by some sort of stress, such as changing brands of milk replacer, changing from waste milk to milk replacer, transport, weather, vaccinations, or dehorning, and are usually temporary. Pathogenic scours can be caused by any bacteria or virus. Infection can occur from contact with other calves, through workers handling the calves and through the environment.

Calves can lose 5 percent to 10 percent of their bodyweight due to water loss within one day of scouring. Fluid loss above 8 percent requires intravenous treatment, and above 14 percent can result in death. The amount of water lost can be approximated by skin tenting, gum condition, attitude and ability to suckle.

To evaluate dehydration using skin tenting, pinch a fold of skin and count the seconds it takes to flatten. Less than two seconds indicates normal hydration. Two to six seconds indicates 8 percent dehydration. Greater than six seconds indicates severe dehydration — more than 10 percent. Normal gum condition is indicated by pink, damp gums. Dehydration causes white, dry gums, indicating 8 percent to 10 percent dehydration.

To be effective, oral rehydration solutions should contain all of the essential components needed to stay hydrated, including water, sodium, glucose, glycine, alkalizing agents, potassium, chloride and gelling agents. Water is the essential ingredient in a rehydrating solution. Sodium will promote water intake. Glucose aids in sodium absorption. Glycine has been shown to enhance the absorption of glucose. Alkalizing agents will decrease metabolic acidosis and may provide some energy. Potassium and chloride are needed to maintain blood pH for muscle contractions, especially in the heart. Gelling agents can be added to coat inflamed intestinal mucosa.