Proper blanketing can sometimes seem like more of an art than a science. There are few concrete rules due to all of the variables that can affect a horse’s comfort level in inclement weather, and it can be difficult for horse owners to decide the best system for their horses.
The following advice from these veterinarians can help to give you more peace of mind this winter: Meghan Breen, DVM, a junior associate at Virginia Equine Imaging in Middleburg; Teresa Burns, DVM, a clinical instructor at Equine Field Services, Department of Veterinary Clinical Sciences at Ohio State University in Columbus; and Marta Grandstedt, DVM, a private practitioner in Simi Valley, California.
Blanketing a Clipped Horse
Blanketing your horse requires common sense. Horses should be blanketed when temperatures are low enough that they become cold. But at what point does a horse become cold? Horses are comfortable at a wider range of temperatures than humans are, so just because you are cold doesn’t mean your horse is, too, Dr. Breen says. Unclipped horses can be comfortable at temperatures as low as 50 degrees. Horses that live in very cold areas and are able to acclimate by growing an adequate winter coat can be comfortable at temperatures as low as 5 degrees Fahrenheit.
Because horses usually take about 21 days to acclimate, it makes sense to blanket a clipped horse more heavily for the first few weeks after clipping.
Clipped horses should not be left outside in wet conditions during the colder months, but horses that are not clipped can be comfortable in particularly cold and wet conditions, as long as they are wearing some kind of waterproof material.
Important Safety Features
The vets agree that correct fit is the most important safety aspect of any blanket. Dr. Grandstedt says that a poorly fitting blanket can cause as much or more damage than a bad saddle, due to the potential for sores or the threat of tangling a leg in a loose strap. A blanket should be loose enough to prevent rubbing, but straps should be snug enough to prevent a horse from catching its leg.
Blanketed horses need to have their blankets removed frequently to check for rubs and sores, skin condition and to make sure the blanket’s lining is dry, say Dr. Breen and Dr. Grandstedt. Keep a daily routine to keep your horse safe from common injuries associated with blanketing. Rubs are most commonly seen at the point of the shoulder or at the withers.
Even a properly fitting blanket can lead to hair loss from rubbing if left on for long periods of time, says Dr. Breen. She also says that even once you are sure that your horse is not suffering from an ill-fitted blanket, you should regularly check that the straps and buckles are intact.
Signs of Overheating
Even before he begins to sweat, an
overheated horse’s respiratory rate will increase. Dr. Burns says that the respiratory tract is an important site of evaporative heat loss, which is a way that the horse dissipates heat to his environment. Because the normal respiratory rate of an adult horse is between 10 and 20 breaths per minute, rates higher than this range indicate a problem, especially if there is any nostril flaring. Taking a horse’s body temperature is not a good indication of overheating, as a horse will be uncomfortable even before its body temperature increases.
Signs a Horse is Cold
Shivering or muscle tremors can indicate that a horse is uncomfortably cold, but these symptoms can also be signals of pain or electrolyte abnormalities, says Dr. Burns.
If extremities—ears, tail and distal limbs—are cold to the touch, the horse might be cold.
Additionally, low rectal temperatures, or those lower than 97 F can indicate a low core body temperature in young foals. But keep in mind that low temperature readings can also be caused by feces or gas in the rectum of an otherwise normal horse. Horses that are too cold might also seek shelter, standing near a tree line or a run-in shelter and might stand in close groups.
Ensure Comfort After Sweating
The horse should be bathed to remove sweat and debris from his coat, Dr. Burns says. Ideally, the horse should be allowed to dry thoroughly before blanketing, since blanketing a wet horse (especially with thick, dense blankets) can encourage skin problems. However, a horse should not be turned out in adverse weather conditions with a wet coat. If it is necessary, an insulated, waterproof blanket should be applied.
The Risks of Overblanketing
Horses can sweat under their blankets, which creates a hothouse for all kinds of skin infections, Dr. Grandstedt says. She also says blankets tend not to dry so they don’t keep the horse very warm when put back on.
Some horse owners are concerned that blanketing a horse heavily can permanently flatten the coat, but Dr. Grandstedt says that the hair will only be flattened temporarily. This is both from the weight and the fit (like helmet head) and because of the warmth retained under the blanket.
When the horse is cold, their hair stands on end and they are very fluffy. This lets air in around the hair shafts, making it more like down. It provides maximum insulation. During warmer weather or when worked, the hair lays down. This way they can blow off heat and evaporate sweat easier. If you leave the blanket off and it gets cold, the horse’s hair will eventually stand up.
Other Factors to Consider
Consider this when blanketing: body mass, hair and digestion. If your horse is deficient in any of these categories, that might provide reason to blanket more heavily.
For example, very young horses and very old horses typically require more energy to stay warm due to their lower body masses, so it might be appropriate to blanket them more heavily. Digestion produces metabolic heat, so if your horse isn’t getting much hay or eating well, blanketing might be appropriate, Dr. Breen says.
Dr. Grandstedt says she sees no reason to blanket a young horse that is just growing up and has all of his hair. “I would be more inclined to blanket an older horse, especially one that has trouble keeping weight on,” she says.
A common blanketing mistake is to put a blanket on an older, retired horse that lives outside and does not get individual attention on a daily basis, Dr. Breen says. These horses can lose weight in the winter, which could go unnoticed if the blanket is not removed regularly.
Using Waterproofing Products
Blanket waterproofing products are generally safe, particularly those based on mineral waxes (such as Nikwax), Dr. Burns explains. She warns that some products contain fluorocarbons as their active ingredients, which could be problematic if not used correctly. She says to avoid using these products on blankets worn by horses with skin allergy problems, such as recurrent hives or those who are pre-disposed to allergic reactions.