The author is a partner in the Maria Stein Animal Clinic, Maria Stein, Ohio.

An evening vet call came in that a high value bull calf was down. I wasn’t far away from the calf grower, so I soon pulled in to find Becky running subcutaneous (SQ) lactated ringers (LRS) into a calf that was unable to stand and suck. This delivery method may help, but calves in this condition really need intravenous (IV) fluids.

The calf’s eyes were recessed from the front corner by 5 millimeters and the skin of the neck tented for more than four seconds. These results indicate 10% or more dehydrated. On a 100-pound calf, 10% is 10 pounds or 5 liters, and the fluid was still coming out.

I clipped and scrubbed the neck over the jugular vein, placed a 14-gauge catheter, and ran that first liter of lactated ringers full bore. After I got the catheter sutured in place, I bolused 180 cc of hypertonic saline into the vein. This calf was older than a week and its potential to have depression due to acidosis was high, so I also bolused two bottles of sodium bicarbonate IV by syringe.

I hung the second bag and slowed the rate to one drop (10 drops per mL in the drip chamber) per second and added 50 cc of 50% dextrose and 5 cc of high potency B vitamins to the bag. Calves have limited energy stores, and this gives the calf a little energy without waiting for the liver to process the lactate in LRS for energy. Don’t overdo the dextrose, as you will cause the kidneys to diurese, which is the last thing you need a dehydrated calf to do. B vitamins are needed for many chemical reactions, and sick calves have a lot of those going on.

After we administered enough fluids to support internal organ function, I gave 2 cc of Flunixin IV to fight inflammation and offer some pain relief. I also administered a SQ antibiotic that had a low potential to alter the gut biome. The antibiotic treatment was optional and we usually reserve it for calves that show us signs of septicemia. These signs include blood in the feces, fever, and blood-injected sclera of the eyes. This calf did not show this, but the farm had a history of bacterial calf issues.

This is a big change in the last 20 years. At one time, the majority of calf scours were bacterial, but prevention has changed our populations. Now the majority of cases are cryptosporidium, with rotavirus and coronaviruses a close second.

Fluids and nutrients

I showed Becky how to hang a third bag of IV fluids and asked her what oral electrolytes she had. She had a supply of one of the about six excellent oral electrolytes that are available. It’s best for calves to stand before we tube feed them, but we can prop them up to give oral electrolytes, and we will give oral electrolytes every four hours until they drink milk.

I discourage tubing milk because the inability to suck is an indication that hydration and acid base balance are not appropriate for good gut motility. This can lead to abomasol bloat and potential death. Our job is to save them, not kill them.

We balance this with the fact that returning to a milk diet is important because the energy sources in milk are more sustaining than in oral elelctrolytes. Protein in milk is also needed for sick calves to heal.

Becky asked why I gave the hypertonic saline. I said that was to move fluid from extracellular spaces and other fluid storage in the body into the circulatory system to reduce hypovolemic shock. When we do this, we need to replace the fluids that we moved or we actually make them more dehydrated than they were. This is why we run the third liter of fluids and will give oral fluids to the calf soon.

Timely treatment is key

The next morning, I stopped to check on the future super sire. Becky met me at the pen to report that the 8 p.m. tube feeding was challenging, but at midnight the calf was standing and tubed easily. At 4 a.m., it sucked down the electrolytes, and at 8 a.m., the calf drank its milk. I had the feeling of being a hydration hero, but really, the credit goes to Becky.

Two days later, I treated another calf much the same way, but it died overnight. So then, I was a hydration zero. What was the difference? The second calf was more dehydrated, and it didn’t get a four hour follow up.

The key difference between a hydration hero and a hydration zero is timeliness and intensity of treatment. Most calf farms never need to place an IV catheter because as soon as a calf drinks slowly, it gets supplemented twice a day with electrolytes in addition to its milk meals.

We never add the electrolytes to the milk because that can create undesirable osmolality that actually dehydrates the calf. They really need the fluids. Better calf raisers will use LRS under the skin to perk a calf up enough to drink on its own, but they realize that it still needs oral electrolytes and milk to become replenished.

Hydrated calves do better

We oversee calf depots or collection sites that ship thousands of calves each week, picking them up from farms, grouping them, then loading them in semis or trailers for a long haul to the calf ranch. They do really well — better than many calves that stay home.

The key is hydration and nutrition. They receive a hydration electrolyte or milk replacer on arrival from the farm and milk replacer twice daily for their stay. On shipping day, they get milk in the morning and a few hours later, they get the hydration electrolyte before they are loaded on the truck.

We use two different kinds of electrolytes at the depots. One is for routine hydration and the other is for sick calves. There is significant difference in cost and composition of those electrolytes.

Let’s talk about electrolytes for sick calves because every dairy needs a good one and some of the most popular ones don’t meet our standards. Electrolytes for sick calves must supply enough sodium to correct extracellular fluid deficits with a concentration of 90 to 130 mm/L. They include agents to facilitate absorption of sodium and water like glycine, acetate, or glucose. They provide alkalinizing agents like acetate, propionate, or bicarbonate to correct metabolic acidosis. They provide enough energy to correct hypoglycemia, and they facilitate a healthy gastrointestinal (GI) environment. A strong ion difference of 60 to 80 is recommended.

This can all get pretty technical, but it is worth asking if the electrolyte you are purchasing meets these criteria or is it just the best deal for the seller. Maybe they sell it because they always have.

There is a science to becoming a hydration hero. Ask your veterinarian to help you sort out your program. It’s pretty rewarding to save lives.