The trouble with calf scours is that it is not a single disease that causes it. Instead, it is a clinical sign that is associated with several diseases. Despite its many causes, one common sign is your calves having diarrhea. Regardless of what is causing it, diarrhea prevents the absorption of fluids in the intestines. Because of this, the onset of calf scours is very serious.
As any producer will tell you, it is severe. Calf scours is the primary cause of death in calves from 2 to 30 days of age. However, despite the seriousness of this disease, it is relatively treatable. The leading cause of death from this disease is dehydration from fluid loss. Let us look at ways to treat and prevent calf scours from taking their toll on your calf herd.
What causes calf scours?
As I have mentioned above, not one disease will cause scours to show up. The known causes can be divided into two categories: Non-infectious and infectious causes. The non-infectious are often referred to as contributing factors. Whatever you want to call them, there are interesting interactions between the non-infectious and the infectious causes. Preventing infectious causes is usually pointless unless you take profound control of the non-infectious causes.
Non-infectious causes
Your non-infectious causes are often what you call shortcomings in calf management. Things like nutritional deficiencies, inadequate environment, and insufficient attention to the calf are some causes. Or it could possibly be a combination of all 3 of these.
Nutritional deficiencies of the cow, especially in the last trimester, are a significant cause. When the nutritional demands are not being met, the colostrum’s quality and quantity will be affected. The cow not getting enough energy and protein can cause this. Deficiencies in both vitamins A and E have also been associated with a greater incidence of calf scours.
Muddy lots, crowding contaminated lots, calving heifers and cows together, and weather factors can cause stress to the newborn calf. When they are stressed, this increases their chance of being exposed to infectious causes. A cold, wet calf often lacks the vigor to nurse sufficient colostrum early in life.
Insufficient attention to the calf will be an issue during difficult births or lousy weather conditions. When the calf is born, it lacks the antibodies to fight scours. This reason is why it is crucial for them to drink its colostrum right after they are born. All of the antibodies they will need are based on that colostrum. The longer they take to drink it, the less effective it will be.
Infectious causes
Scours pathogens are viruses, bacteria, and microscopic parasites. The damage that these pathogens do will be in the intestinal tract. They cause the cells of the intestinal lining to malfunction and die. When the linings are damaged, it makes it difficult to absorb the milk that is ingested.
E. coli is the single most important cause of bacterial scours in calves. The K99 strain causes diarrhea by impairing the ability of the intestines to digest and absorb milk nutrients. Most newborn calves will pick this up from the environment if sanitation is marginal. This particular strain, however, is only capable of causing scours when the calf is under a week old.
Rotavirus, coronavirus, and a protozoan parasite called Cryptosporidia can cause damage to intestine walls. Healthy cows and heifers carry them through their manure and release them into the environment. The scours they cause tend to be yellow and watery. Because they are not susceptible to antibiotics, the only treatment is replacing the lost fluids in the calf till the intestine wall is repaired.
Symptoms
As is well known, one of the main symptoms of scours is diarrhea. A pathogen damages the intestine, preventing it from absorbing water and nutrients. The calf loses a significant portion of its nutrients as a result. Because of this, treating the diarrhea is the main focus. The symptoms of dehydration, such as sunken eyes, weakness, and mouth dryness, are signs to look out for.
Acidosis is another sign that your calf night has scoured. The loss of salts creates an imbalance in the normal pH of the calf’s system, causing acidity to take over. Calves with acidosis are weak and coordinated. They will show a drunken kind of wobbly gait when they walk. When you make them nurse, their suckle response is just a weak chewing motion. The calf cannot stand as it worsens and will become lethargic and sleepy.
Another common problem with calf scours in colder weather is low blood sugar. Having scours will prevent them from absorbing the milk’s nutrients, so they won’t be able to replenish their body’s sugar reserves. If a calf has low blood sugar, it will generally develop subnormal temperatures as it loses its ability to maintain body heat. Low blood sugar also contributes to weakness and lethargy-induced acidosis.
Treatment of scours
When it comes to treating calf scours, the primary treatment is replacing fluid losses from diarrhea. The intestinal wall will often repair itself, so you need to provide fluids to keep the calf healthy. Young calves are more prone to scours because of their liquid diet. 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, according to research from the Texas AgriLife Extension, a calf is approximately 70% water at birth.
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 how much liquid they need, multiply the weight of the calf by the percentage of dehydration and divide by 2 to get quarts.
Being able to use antibiotics will depend on what is causing the scours. If rotavirus and the like are what is causing it, then it will be basically useless to use them.
Prevention
The economic benefits of prevention far outweigh that of treatment. It is the most essential and cost-effective way to invest your time. When it comes to prevention, there are three main areas to look at.
Using good hygiene will minimize exposure, which will prevent the disease. When it comes to improving sanitation, you can go with many things. The options include:
- Improving the general sanitation of the calving lots.
- Disinfecting calving pens between uses.
- Sanitizing calf treatment equipment.
Isolating scouring calves is another step.
When it comes to prevention, making sure the calf gets enough colostrum is vital. It is the most critical way to determine the calf’s immune system in early life. Not doing this can increase the calf’s risk of getting sick 3x-10x. I talk about the importance of colostrum in a previous post, “5 astonishing truths about colostrum to start calves right”.
Lastly, vaccinate your cows before calving. Proper vaccination against E. coli, rotavirus, and coronavirus is essential. It will increase the antibodies that she will pass to the calf through her colostrum.