Horses are one of the most weather adaptable animals on earth. Horses evolved in the harsh climate of North America and migrated over the entire world from the frozen tundra of the Arctic to the fierce heat of the Sahara. Our job is to help them stay as healthy as possible given the restrictions and constraints of domestication.
Environment
Horses do fine outside during the winter provided they are in an appropriate environment. They need a natural or artificial shelter to break the wind and rain. They do not seem to mind the rain, wind or cold unless in combination. If no shelter is available, they turn their tail to the wind, and lower their head, often shivering to keep their body temperature up. Shivering is their normal adaptation to survive and not as significant a sign as humans shivering. They also need an environment that allows them to exercise to stay warm and one that has an elevated place to stand out of the mud, manure and urine.
Feed
With cold weather, exercise usually diminishes but your horse actually needs more feed to stay warm. In some extreme weather, horses require fifty percent more calories than normal to maintain weight and fat insulation. One thing that generates heat is digesting roughage in their large colon. Feed your horse larger meals of hay in the evening to help keep them warmer at night. Feed in a clean, dry, sheltered place to reduce hay loss.
Blanketing
Most horses in California are over-blanketed. If your horse has his natural coat, or most of it, he is far better off without a blanket. Blankets flatten out the hair coat and eliminate the natural insulating effect. If your horse is mostly body clipped then we need to blanket but only if very cold and/or rainy and windy. Raining and warm is ok. I see many blankets doing harm. Blankets put on for cold nights but left on in the morning when the sun comes out, results in horses sweating under the blanket potentially inducing skin disease. Wet blankets are far worse than no blankets. They can make the horse colder than would be otherwise, can induce skin disease and can create pressure sores over the withers. Most blankets are not truly waterproof so diligent care is needed if blanketing.
Common Winter Problems & Ailments
Hoof Abscesses. Winter is prime time for hoof abscesses. There are multiple causes including: 1) Standing for long periods in mud containing feces and urine. Feces are bacteria laden and urine has hoof degenerating properties. Hoofs soften and degenerate and bacteria make their way in through natural defects and “set up house” resulting in an abscess. 2) Decreased exercise (necessary for good hoof health) and decreased hoof care. The best defense against abscesses is continued regular exercise and care and getting them out of the mud and waste.
Scratches/Mud Fever. This usually starts with the lower legs, especially the pastern area, being chronically wet. The skin devitalizes resulting in inflammation (scratches), cracked skin and decreased ability to fight infection (mud fever). This is usually the result of standing in high wetness but can result from just not really drying out well. For instance, riding in the evening and hosing off. Your horse may go back to a dry environment but his pasterns remain wet for a long period into the night, especially in winter. It is important to dry well and keep your horse from being chronically wet. If wet pasterns are unavoidable, apply desitin or similar diaper rash medicine to help with the symptoms.
Rain Rot. A disease caused by a common bacteria but most people think it looks like a fungal disease. It takes advantage of devitalized skin (from being chronically wet) especially on the top line. It appears as a loss of hair that comes off easily and has large flakes of skin with it. It is less likely if a horse is able to roll to stimulate the skin and keep the hair from matting. Keeping the horse dry and vigorous grooming to stimulate the skin are key.
Colic. There is an increased risk of colic in winter due to decreased exercise and drinking. Your horse may not drink as much water due to the water being cold or not wanting to go across a muddy paddock to get it, etc. In winter there is also an increased likelihood of spoiled food and often less consistent feeding schedules kept. Make sure clean and easily accessible water is available at all times. Even add some warm water to their source on very cold nights. Be diligent about exercise and checking the quality of your feed.
Older Horse. Remember, the older horse may not be alive if in “the wild”. Everything hits them harder so we have to care for them more. They will tend to move around even less than a younger horse in winter so are even more prone to ailments of decreased activity. Their immune defenses are less efficient so they are more prone to infections. Their teeth and intestines are less efficient so they are more prone to digestive disorders. A good clean dry shelter with room to exercise is key. Plenty of high quality feed (hay or soaked pellets depending on dental health) can’t be stressed enough along with easily accessible fresh, not too cold, clean water.
Take Home. Horses are tougher than their owners when it comes to weather. However, due to captivity they are less able to cope with weather in their natural way. We need to try to minimize our interfering effects. Provide them a reasonable mud free shelter. Continue to exercise and groom them vigorously in winter even if you do not want to. Feed them plenty of good quality food on a regular schedule. If you must blanket, take it off at every opportunity even if you do not want to.
– Robert W. Steere, D.V.M.
