It’s important to know the signs of calf dehydration

Dehydration among calves is a severe problem that is often overlooked among producers. It can be caused for many reasons, typically from the summer heat and scours. The time from recognizing the symptoms to providing treatment is crucial.

When it comes to treating dehydration, producers need to be ready to step in quickly. It does not take long for a dehydrated calf to deteriorate if not treated promptly. While scours is often the cause, if you do not rehydrate with fluids, you will lose the calf.

The degree of dehydration can be hard to recognize, so observation is the key. Producers should educate themself on what to look for and what treatments to do. Here are five signs to look for when diagnosing dehydration in your calves.

What causes dehydration in calves?

When it comes to young calves, the primary cause of this problem is scours. Diarrhea from scours prevents the absorption of fluids in the intestines. Also, bodily fluids pass from the scouring calf’s body into the intestines. Along with the more watery form of their feces, you get a recipe for problems during this time.

The young calf’s primarily liquid diet makes them more prone to getting scours. They are still nursing off their mommas and have yet to begin eating more solid foods such as forages and feed. Another factor to consider is that at birth, according to research like that from the Texas AgriLife Extension, a calf is approximately 70% water at birth.

The three major causes

Any digestive upset can cause scours, but the three major causes are bacteria, viruses, and parasites.

• Bacteria: Such as Escherichia coli and Salmonella are common in newborn calves (usually younger than two weeks old). However, Salmonella can affect cattle of any age.
• Viruses: These are things like Rotavirus and Coronavirus, and they commonly affect calves in their first few weeks of life. Usually 1 to 3 weeks.
• Parasites: Normally, Coccidia and Cryptosporidium parvum can cause diarrhea in young calves.

Even though these are the prominent three causes, they are not the only ones. Things like inadequate nutrition can also cause scours to pop up. My previous post, “Calf scours: what to watch for, how to treat it,” goes into more detail about this problem and how to handle it.

Along with the fluid loss from scours, the body also loses the electrolytes needed to maintain all bodily functions in the calf. This loss is why the death caused by scours is typically from dehydration. The loss of electrolytes causes a condition called metabolic acidosis, which will kill the calf in less than two days if not treated quickly.

Signs of dehydration

There are generally five signs you can look for when trying to decide if the calf is dehydrated or not:

1. Look at the calf’s overall attitude. A calf suffering from this will be more lethargic, will not stand as quickly, and will show a reduced interest in nursing.
2. Check their suckle reflex. This check is done by putting a finger into the calf’s mouth to see if it will start to suckle
   

   Courtesy of Penn State Extension

   on it or not. A well-hydrated calf will have a strong suckle reflex, while a dehydrated one will have a very weak response.

3. Look at their eyes. As a calf becomes dehydrated, the eyeballs will pull inward, forming a gap between the eyelid surface and the eyeballs.
4. Check the skin tend. This test is performed by pulling the skin and then releasing it. The more dehydrated the calf is, the longer it will take the skin to snap back into place. It is normal if the skin flattens in less than 2 seconds. If it takes 2-6 seconds, the calf is moderately or 8%, and if it takes longer than 6 seconds, it is severely or 10%.
5. Check their gums. In a healthy calf, the gums are moist, but as they become dehydrated, they will become sticky and take longer to return to normal color when pressed with a finger.

Prevention

Since calf dehydration is primarily the result of calf scours, it is essential to prevent this disease from happening in the first place. Taking the proper steps can keep this from becoming a problem at your place.

Ensure all the calves get colostrum within the first 6 hours from birth. If they do not nurse from the cow, then provide colostrum via a bottle or tube. I go over what to look for in this in a previous article, “6 tips for colostrum replacer”. The colostrum is a calf’s most crucial defense till its own immune system kicks in.

The best way to prevent pathogens from popping up is to provide a clean environment during birth. The calving areas should be clean and uncrowded. No amount of colostrum or treatment can make up for excessive exposure to bacteria and viruses. Change the calving areas many times during calving to minimize exposure.

Providing a balanced mineral program to the momma cows before and after calving will also go a long way. This program will ensure that she has the foundation for average electrolyte balance and milk production.

Vaccinating cows during their final trimester can prevent Salmonella, Rotavirus, and Coronavirus infections. Vaccination will cause the cows to produce immunoglobulins that will attack these organisms. When the calves receive their colostrum and start nursing, they will receive these nutrients.

Treatment

The type of treatment you will need to use depends on the severity of the calf’s dehydration. You can use oral rehydration solutions if they are light to moderately dehydrated. Severe dehydration will require an IV solution to get them back to where they need to be. One thing to note is that even though they are receiving electrolytes, they will still need milk or milk replacement to supply them with energy and protein.

photo courtesy of Cargill

Feeding a calf too many electrolytes is nearly impossible, but giving them too little is a common problem. To calculate the amount of liquid to provide them with, multiply the weight of the calf by the percentage of dehydration and divide by 2 to get quarts of fluid.

For example, if a 100lbs calf is 8% dehydrated (100 x 0.08), then you will need 8lbs of liquid. Next, 8lbs of the liquid divided by 2 equals 4 quarts required per day in addition to the regular milk feeding.

Summer heat affects these calculations without a doubt. When the temperatures get over 90 degrees, you will need to increase the amount by 50%. If the temperature is over 100 degrees, then you will need to double the amount to give them.