Calves born in cold weather may suffer frostbite, especially if they are unable to suckle the cow before they chill. Dr. Andy Acton, Deep South Animal Clinic at Ogema, Saskatchewan, says there are two problems when dealing with cold weather.
“One is hypothermia, and the other is frostbite, and they don’t always happen together,” he said. A calf can be chilled, but not frostbitten (no frozen tissue). This varies with temperature, wind chill, and how long the calf is in cold conditions.
A sick calf may chill and suffer frozen extremities, due to circulatory impairment. A scouring calf, for instance, may be dehydrated, and extremities become cold and more vulnerable to freezing. The body is shunting blood into the body core to keep important organs alive, and therefore the legs, ears and tail get cold. Even an older animal may suffer frostbite if blood circulation has been compromised.
Calves born during blizzards or cold weather become immediately chilled, and older calves may suffer frostbite if they don’t have shelter. A calf with body temperature below 100 degrees Fahrenheit needs warming (normal for a calf is 101.5 degrees). It pays to have a thermometer and take the calf’s temperature, to know how cold he is. If his temperature is a little subnormal, like 98 degrees, he can warm up readily, if you provide warm colostrum and a warm place out of the cold. But if his temperature is below 90 degrees this a serious problem.
“You need to get these calves warm and keep them warm—and don’t put them back outside very soon. They are compromised and it takes a while for them to recover,” said Acton.
Dr. Steve Hendrick, Coaldale Veterinary Clinic, Coaldale, Alberta, says windbreaks and bedding can help prevent hypothermia and frostbite in calves, but sometimes they still get too cold. With severe hypothermia or frostbite they need to be warmed quickly—but carefully, especially if there is already some frostbite damage.
“Calves have a large surface area and less body mass than a cow, and chill faster. Extremities suffer first—ear tips, tail, and sometimes feet,” he said. Even if the calf isn’t at immediate risk of freezing to death, there is risk for losing ears or tail. If feet are frozen to the point of losing them, the calf will have continual pain and risk of serious infection, and the most humane thing is euthanasia.
If you find a calf that’s been cold too long, try to assess how cold he is and how aggressively you need to try to restore warmth and circulation. Frozen ears or tail will be stiff and solid. Check the feet for sensation by pinching between the toes to see if the calf reacts. A pin prick just above the hoof lets you know if the calf can feel anything—whether or not he reacts. If you warm the calf and his feet are still cold, that’s a clue there’s no blood circulation to the feet.
There are several ways to safely warm calves. If the calf is not severely cold, drying him and putting him in a warm box (breathing warm air) may be enough, especially if you get colostrum into the calf to help warm him from the inside and give him some energy.
Air or water?
Acton has looked at ways people try to warm a hypothermic calf, and feels warm air is usually better than warm water. Some people feel they need to warm the calf as quickly as possible in a hot water bath. “I’ve seen problems with this method. I don’t say a person should never put a calf in warm water. It can be a last-ditch attempt to warm a severely frozen calf, but for a hypothermic calf, warm air works better,” he said.
“Warm circulating air and tubing the calf with warm colostrum (a little warmer than normal body temperature, but not so hot that you can’t put your finger in it) will usually help the most. You can use blankets or towels for bedding, and keep changing them to warmer, dry ones,” said Acton. But if the calf is very cold, with frost-bitten extremities, a warm water bath may be better than a warming box.
Shivering stimulates circulation and helps warm the muscles, but that requires energy, and some calves are too cold to shiver. “Calves are born with fat stores for energy and insulation, but they can go through that pretty fast when they are cold. They need colostrum as soon as possible, to provide the energy they need,” Hendrick says.
When warming cold calves with a warm water bath, don’t use hot water; it should be close to body temperature (102 degrees) because you don’t want further trauma to skin that’s already damaged by cold. A really hot bath can also be too much of a shock to a cold calf.
“To prevent frozen ears on newborns, some people use ear muffs or fold the ears back against the body. The most important thing, however, is just getting them dry and protecting them from severe wind and cold,” said Hendrick. A wet calf chills much quicker than a dry calf.
Ill calf struggles
Also, a calf that is compromised, like sick with scours, has a harder time keeping warm. “During a really cold spell, even older, larger animals can get chilled if they are sick. In feedlots, we’ve seen some of the cattle in sick pens end up with white hairs on the tips of their ears, or even lose their ear tips,” he said.
“It’s not just newborns that suffer frostbite, and sometimes people are surprised when an older calf loses ears, tail or feet, but anything that impairs blood circulation puts a calf at risk,” he explains.
Producers who calve later (March-April rather than January-February) may still run into problems with late winter storms. Temperatures may not stay bitterly cold for as long, but a cold, wet snow in the spring can severely chill new calves, or even older calves—and it can be worse if they are sick. If the calf is cold and miserable, and maybe a little sick, he won’t feel like nursing, and a calf that’s off feed doesn’t have adequate energy to create body heat.