If you live in South Dakota, you probably remember how last week was rather crumby weather. Rain turning to snow, with temperatures in the 30s–it was just delightful.
This kind of weather is hard on everything, but it is quite difficult on new baby calves. Being cold and wet runs down their immune system and makes it more likely they contract a virus or bacteria that causes diarrhea, which in calves is referred to as scours.
Obviously ranchers take care to prevent scours the best they can, however, the prevention techniques might be different than what you might think. Obviously, if it is rainy and wet, one would think you’d just put the cattle in a barn. While that may work of a small number (one to five) animals, it can be much worse to have cattle inside than out in the elements.
For starters, having many cattle in the same area means they all defecate in the same area. This increases the amount of scours causing bugs in the very area the calves are residing, making it much more likely the calves will get sick than if they can be spread apart outdoors. Secondly, cows are clumsy animals that if confined together in a tight area often step on their own calves. This can lead to broken legs at a minimum, or can kill the calf.
That’s why it is better for cattle to stay outside in the rain. To help mitigate the environment, ranchers create windbreaks so the cold wind helps keep the calves from getting chilled. They also try to minimize the mud, by putting down bedding or building mounds that let the rain run off. Having a dry place to lie down makes it much easier on the calves. Also, cows are rotated between paddocks to calve, so that the newest babies aren’t born in the same environment as the older calves.
Although it may also seem surprising, often the cattle are kept off the grass pastures at this time. This is because they can rip up the grass when it is very wet, which is detrimental to the health of the pasture. If they are on grass, that pasture is usually dedicated for spring only, so it has all summer and fall to regrow and stay healthy.
Lastly, cows and calves are vaccinated before the wet weather even starts to turn bad. The cows receive the vaccine before the calves are born, so that they can pass the antibodies for scours to the calves in their milk. The calves are vaccinated right after birth. Usually if vaccines are used, only one or the other is vaccinated, not both.
In spite of all these preventions, calves still can get scours. When they do, the most important intervention ranchers take is to rehydrate the calf. Although the scours is smelly, it is the dehydration it causes that can kill the calf. If the scours is mild, then giving oral electrolyte solutions (which are a lot like gatorade for calves) is sufficient. Otherwise, they bring the calves to our clinic so we can administer the fluids intravenously.
Depending on how much the calves are scouring, it can take a lot of fluids to rehydrate the calf. In addition to rehydration, we can add a special sugar called dextrose to give the calves energy, and/or sodium bicarbonate to regulate their blood pH. Although antibiotics can be used, they are not always part of the therapy and are not as important as the rehydration aspect. Once the calf is rehydrated and can nurse a bottle, we send them back home to happily frolic in the pasture with their mom.