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Animal Health

Veterinarian encourages ranchers to look for positives and learn from blizzards like Atlas

Rapid City, S.D. – Nothing good came from the October 2013 blizzard, but Russ Daly, veterinary specialist with South Dakota State University, hopes producers will learn from it and be better prepared if it happens again. 

“I hope people will be more aware of what could happen and treat animals that survive sooner,” Daly told ranchers during his presentation at the Range Beef Cow Symposium in Rapid City, S.D. 

Leading up to the blizzard, Daly said in South Dakota, they had good moisture and good grass. 

“There was no need to wean early, and because of the warm weather, the animals hadn’t started growing a winter hair coat. In many cases, the calves were still on the cows,” he said.

When the storm hit, many areas like Union Center, S.D. received 1.25 inches of rain during the night. 

Critical temperatures

“We had a situation where cattle were soaked to the skin, so lower critical temperature became an issue,” the veterinarian said. 

Lower critical temperature is how low a temperature an animal can endure before it has to start burning energy to keep warm and keep its metabolism up. 

During the summer, a cow with a wet coat can endure temperatures as low as 59 degrees before she will start burning energy. During this storm the wind chill was 12 to 16 degrees in many areas. With a wet coat, the cow would need to eat 1.5 to two times as much as normal to maintain her energy intake before hypothermia sets in, Daly calculated. 

At the peak of the storm, the wind had 62 mile per hour wind gusts and sustained winds of 49 miles per hour, along with at least 12 inches of snow.

Cause of death

Daly said cattle died during the storm for many reasons, but most succumbed to hypothermia. 

Others became trapped in fences and exerted themselves trying to escape. Some drowned in creek beds and died from exhaustion. 

When ranchers began disposing of dead carcasses, many noticed gallons of fluid pouring out of the nose and mouth of these animals. Daly said they suffered from pulmonary edema. Cattle took in so much moisture during the storm, the heart couldn’t maintain the blood supply to vital organs, and fluid backed up into the lungs and essentially drowned the animal. 

After the storm

More than 20,600 cattle in South Dakota died in this storm. Those that survived suffered a variety of health problems. 

“Some of the cattle suffered a response similar to grass tetany,” Daly said. 

“They were hyper-excitable and twitchy,” he explained. “It is a similar correlation to railroad sickness where animals are hauled for long periods of time without feed and water. When the animal goes back on feed and water, it disrupts their metabolism so much that they suffer from derangement.”

“The grass may also be lacking in magnesium, which adds to the problem,” he added. “There aren’t many treatment options for grass tetany.” 

Many calves suffered from bloat or acidosis and had to be treated. 

“They would resume eating grass or nursing their mothers and overdo it,” Daly said. 

Ranchers also reported gentle cows becoming aggressive after the storm. The veterinarian said after what they went through to survive, some cows may have suffered lung damage. That lack of air may have caused them to become brain crazy.

Immune challenges

Immediately after the storm, Daly said the cortisone levels in the cows increased temporarily changing the immune system. 

Viruses that circulated in low levels through the herd, like IBR, BRSV and pasteurella, became more prevalent because of the animal’s weakened immune system. 

In addition, vaccinations were less effective because of the increased cortisone levels. 

“Ranchers who were planning to vaccinate their cattle had to wait a little longer until the cortisone levels returned to normal,” Daly said. 

Animals also had to be treated for diseases like pinkeye they acquired from the storm. Daly said some cows that became stuck in creeks, stock dams and snowdrifts lost their pregnancies and were found with cleanings hanging out of them. 

Management adjustments

As a result of the storm, some ranchers made management changes. 

“Some decided to hang onto their calves a little longer, so they had to figure out where to keep them and get them started on feed after they weaned them,” he said. 

Overall, Daly said most of the animal problems after the storm came from going back on feed. 

“Ranchers had to adjust their management to allow for the stress level of the cattle,” he said. 

Daly encouraged producers to start the cattle on coarse hay to allow them to readjust to feed. 

“Sometimes, it is just not good enough to do everything right,” Daly summarized. “Bad things just happen.”

“If anything good came from this, it was the opportunity to educate the public about why things happen. It created the opportunity to explain to people who don’t live on a ranch what it takes to raise animals on the northern plains and what you do on a daily basis, so the animals survive and thrive,” he said. 

Daly commented, “As a result of this storm, neighbors were helping neighbors and looking out for one another. People not directly involved donated money and heifers. It brought out the best in people.”

Gayle Smith is a correspondent for the Wyoming Livestock Roundup. Send comments on this article to This email address is being protected from spambots. You need JavaScript enabled to view it..