Establishing a Protocol for Oral Electrolytes

Over 50% of pre-weaned calf deaths are attributed to dehydration caused by scours. Young calves have 5-10% more body fluid than adult animals. The average 100 lb. (45.5 kg) calf requires 4.5 liters of water per day! Scouring calves may require an additional 20-30% of daily water intake to maintain body functions.

Establish a Protocol

Farms should have a standard operating procedure for diarrhea treatment that includes when to use oral electrolytes, how much to give, and any other care needed. Train employees to identify scours and probable causes. 

Diarrhea in neonatal calves usually results from 2 different sources; nutritional or pathogenic. Nutritional scours may be caused by a change in milk source, volume, or concentration. Weather, transportation, vaccination, dehorning, or any other stressful event may also cause nutritional scours. Nutritional scours are temporary, and no damage is done to the intestinal villi, however, just as much water loss and dehydration can occur as in a calf dealing with pathogenic diarrhea. It is important to closely monitor these calves and treat as needed.

In reality, just about any bacteria or virus on the farm can cause pathogenic scours. Typically, calves will show signs of scours between the ages of 1-3 weeks of age.  During this time period, colostral immunity is wearing off and the calves own immune system has yet to ramp up and provide full coverage. Common causes for pathogenic scours include; rotavirus, coronavirus, E. Coli, salmonella, and cryptosporidium. Work with your veterinarian to determine which pathogen you are dealing with. This can be done by culture work, or estimation based off symptoms and age of calf. Click here for a helpful guide for decoding diarrhea.

Water loss in calves occurs rapidly, all employees must be able to identify and treat sick calves quickly and efficiently. One option is to train employees to rank scours on a scale of 1-5, with a lower number being ideal.

Score 1 – normal feces, consistency of pudding.

Score 2 – less firm, consistency of yogurt.

Score 3 – consistency of syrup, loose, watery, strong odor.  Considered scours and needs treatment.

Score 4 - consistency of fruit juice with fecal matter still present, needs treatment.

Score 5 – consistency of water, no fecal matter, or with mucous and/or blood, most definitely needs treatment.

How Much to Feed

Typically, on most farms I have visited, calves receiving oral electrolyte treatments receive 2 quarts of electrolytes mid-day, between milk feedings.  However, this may not be enough, depending on how dehydrated the calf is.  Calves with a diarrhea scour of 3, showing no other signs of sickness are typically 4-5% dehydrated. Calves with a diarrhea of scour of 4-5, and that also exhibit sunken eyes, skin tent, and depression, are usually about 8 % dehydrated and may require an additional electrolyte feeding. Calves showing more severe signs of dehydration will need IV fluids. 

A simple calculation can be used to determine the volume of electrolytes needed. First, multiply the weight of the calf by the percent dehydration.

One gallon of water weighs about 8 pounds, a quart of water weighs about 2 pounds.  Divide the amount of water lost by 2 and this is how many quarts of electrolytes the calf will need, in addition to milk feedings. 

The same calculation can be done in metric.

One gallon of water weighs about 3.79 kilograms, one liter of water weighs about 1 kilogram. Divide the amount of water lost by 1 and this is how many liters of electrolytes the calf will need in addition to milk feedings. The amounts can be rounded up for ease of mixing and delivery.

Keep in mind that some pathogens damage the intestinal villi, while others cause hypersecretion of water into the digestive tract. These conditions can lead to decreased absorption of fluids, and often diarrhea will look like it is worsening, when in fact the treatment is working. In situations such as these, the frequency of electrolyte treatment should be increased. If the calf is alert, active, and eager to eat, you are headed in the right direction.

Milk Feeding During Electrolyte Treatment

A common practice is to withhold milk during times of electrolyte treatment.  However, calves need enough energy to maintain body weight, as well as their immune system, especially when they are sick. Electrolyte solutions cannot provide enough energy or protein for maintenance. 

Although the pathogen is damaging intestinal villi, in most cases, the gut is still functional enough for the calf to continue to benefit from milk feedings. Studies have shown that fecal scores were similar and body weight was greater for calves fed milk during the electrolyte treatment period. One exception may be when dealing with coronavirus. Coronavirus damages the cells of the small intestine, as well as some of the cells in the colon, and completely destroys the cells of the villi.  In this case it would be better to remove milk feedings to avoid inducing osmotic diarrhea. Electrolyte therapy should be adjusted to more frequent feedings to replace the milk. The immature crypt cells will replace the damaged villi within 48 hours, and milk can be reintroduced gradually.

It is very important to work with your veterinarian and determine what pathogens you are dealing with on your farm.  Then steps can be taken to establish a protocol for oral electrolyte therapy, and any other treatments needed. 

Written by: Mariah Gull, M.S.