While companion animals are certainly susceptible to some winter hazards, plunging temperatures pose a special risk to livestock. These animals are typically housed outdoors, where they are exposed to cold temperatures and changing weather conditions.
Therefore, it is essential that their owners take active measures to keep them safe during the winter months.
The comfortable temperature ranges for cattle and horses differ, with horses tolerating a far wider variety of temperatures than cattle:
- Cattle 40-70°F
- Horses 10-80°F(1)
Temperatures below these levels are expected to have effects on the health of the animal. These effects can vary, but the most common effects of cold weather are hypothermia, dehydration, and (in the case of horses) colic.
Most livestock are well-equipped to tolerate moderately cold temperatures. Wind and moisture, however, can dramatically reduce cold tolerance. Livestock that are exposed to wind, moisture, and/or extreme cold need to have their daily caloric intake increased by approximately 30% in order to provide fuel for maintaining their internal body temperature.(1)
If the body temperature of a horse or cow falls to 95°F or below, the animal should be removed from the elements and placed in a sheltered area such as a barn or garage. Blankets or warm water baths can be used to facilitate reheating.
Dehydration poses a significant risk to large animal patients during the winter months, for several reasons. First, ponds and water troughs are subject to freezing when the temperature plunges below 32°F. Therefore, owners of livestock and horses should take care to clear ice from ponds and water troughs at least twice daily, at a minimum.
Even in the absence of freezing, however, cold water temperatures can decrease palatability and water intake.(1) Ideally, the water that is offered to large animals should be actively heated to at least 37°F. This will ensure that freezing does not occur and encourage animals to drink readily.
When electric tank warmers are used to heat water troughs, care should be taken to inspect the heaters on a regular basis. Frayed wires can lead to an electrical voltage being discharged into the water. While large amounts of voltage pose a potential electrocution risk, even a small amount of electrical current through water can make drinking unpleasant and lead to decreased water intake.
Dehydrated livestock require rehydration. In some cases, this can be accomplished by simply providing access to warm water. In more severe cases, however, a nasogastric tube or intravenous catheter may be required for enteral or parenteral fluid administration.
Cold weather is associated with an increased incidence of colic in horses. Horses prefer to drink water at a temperature of 45°F to 65°F and must drink at least 10 gallons of water per day in order to facilitate digestion.(1,2) Cold temperatures often result in decreased water intake, which may significantly increase a horse’s risk of impaction colic.
Hypothermia alone, even in the face of adequate water intake, can also increase a horse’s risk of colic. Horses with a full coat can typically keep warm throughout the winter, provided there is adequate access to shelter from wind and moisture. Horses that have been clipped, however, should be covered with a blanket to help retain warmth. Blankets should be changed if they become wet, in order to prevent freezing that will further contribute to hypothermia.
Like other livestock, horses benefit from caloric supplementation during the winter months. Providing 24-hour access to forage allows the horses to maintain body warmth, facilitating digestion. Grain and sweet feed can also be used to provide additional calories, but their digestion does not generate the same internal heat as access to forage.(2)
If a horse does develop impaction colic during the winter months, there are several components to treatment:
- Pain medication, to alleviate gastrointestinal spasms
- Intravenous fluid rehydration, to promote colonic motility
- Nasogastric fluid administration, to break up the impaction
While some cases of impaction colic may require surgery, the majority of cases respond well to medical management.
As the winter months approach, it is important to speak with clients about their winter weather plans for their livestock. Spread the word on farm visits, but also consider mailings, Facebook posts, and other methods of reaching your large animal clients.