Frostbite in Cattle

Livestock Update, February 2001

Dr. W. Dee Whittier, Extension Veterinarian, Cattle, VA-MD Regional College of Veterinary Medicine

With the coming of winter and calving season prevention of frostbite becomes an issue for many of Virginia's beef cattle producers. Depending on winter weather, significant calf losses can occur as a result of severe winter weather.

Frostbite is the damage to body tissues that occurs when these tissues freeze. The extremities are most at risk. Frozen ears and tails result in changes of cattle appearance but do not affect cattle performance significantly. Frozen feet generally result in a calf that must be put to sleep. Occasionally teats of a recently calved cow freeze resulting in mastitis and frequently loss of milk production in at least one quarter of the udder.

Newborn calves are most at risk because they are wet and because they have a large surface area in relation to their total body mass. Calves are not fully capable of maintaining temperature the first several hours of life. Calves probably have a circulatory system that is less able to respond to cold changes as compared to more mature animals.

Weather conditions have a great effect on the risk of frostbite, above and beyond just creating low temperatures. Wind is often the biggest factor. The effect of wind is often referred to as wind chill and tells how living things "feel the temperature". Wind chill is often many degrees colder than the actual temperature. Humidity has a large effect on cold as well since humid air can take more warmth away from animals. The surfaces on which cattle must rest also have a great effect on the risk of frostbite. If cattle must lie on snow ice or frozen ground they will loose much more body heat than if they can rest on dry bedding or grass. Snow or ice from freezing rain on calves dramatically increases heat loss.

Recommendation for preventing frostbite in Virginia Cattle:

• Provide windbreaks for calving cows when wind chill temperatures are below 20° F.
• Provide bedding for calving cows when wind chill temperatures are below 10°F. Often the most convenient way to do this is to roll out a dry round bale of hay.
• House calving cows and calves less than 1 day of age when wind chills are below 10° F. and calves cannot be kept dry because of snow or rain.

• Detect frostbite early. Examine newborn calves carefully when conditions create a risk. If ear-tips are frozen there is significant risk that feet may be experiencing damage as well.
• Thaw tissues as quickly as possible. Much of the damage of frostbite occurs during the thawing process. Ice crystals form that damage all tissues. A fast thaw decreases ice-crystal time.
• Once tissues are thawed re-freezing must be prevented. This nearly always means housing with heat for several days. Because of damage to circulation from the initial freezing these tissues will re-freeze very easily.
• Tissues that will recover from freezing should stay warm. If tissues are cold to the touch the next day there has probably been enough damage so that blood supply is gone and the feet or other parts will become gangrenous.

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