To Blanket or not to blanket
Updated: May 11, 2020
When my family and I first moved to Georgia from South Florida, one of the biggest adjustments we had to make was getting adjusted to REAL seasons, particularly the winter. In Wellington, Florida the only seasons were summer and a very summer-like winter. When we moved to Georgia, I immediately stocked up on weather-dependent clothing for my kids including sweaters, lightweight jackets, rain jackets, winter coats, etc. Who knew each family member would need so much winter wear! I have also found that both my husband, myself and the girls all have different tolerance levels to the cold! My husband can go out in 35F practically in a sweater whereas I have my winter jacket on in the low 50s.
“Baby It’s Cold Outside!”
There seems to be a principle of nature that no two people can agree on a perfect temperature. The same principle applies that no two horse people can agree on the same blanketing criterion.
Before I tell you the guidelines I loosely follow, I will give you some conditions and consideration to help you best figure out what's best for your horse and their situation.
Thermoneutral Zone (TNZ)
Horses themselves are much better at staying warm than people. They are quite comfortable even when you are reaching for your jacket. Thermoneutral Zone is the range of temperatures in which a standard healthy adult can maintain normal body temperature. For humans, this zone is between 72F and 86F. In perfect conditions, a horse doesn't need to start producing extra internal heat until temperatures reach 41F. Furthermore, horses have mechanisms in place which allow them to maintain comfort in temperatures as low as 18F without the need for blanketing. However, factors such as being body clipped, access to forage, body condition, precipitation, and windshield can all affect this number.
Cold Weather Increases Energy Requirements
The primary way horses can increase their internal heat production is by digesting hay and forage. Digestion is technically a fermentation process which in-turn produces heat. When horses are facing a cold night, the first consideration is to provide them with plenty of hay to "keep the furnace burning." To keep this digestion process working, it is important to also provide access to fresh water. This can get tricky if temperatures drop below freezing.
Shivering and Piloerection
Shivering is one way that horses can increase their internal heat. Rapid muscle contractions that stimulate metabolism facilitates this heat production. Piloerection (or goosebumps) is the raising of the hairs on the horse's coat. This increases the insulation effect of the coat by allowing more air into the space between the horse's hairs. However, horses in rainy or snowy conditions lose their piloerection ability.
Decrease in respiratory rate
While humans have a higher TNZ and will become cold and possibly hypothermic when the environment drops below 72 degrees F (therefore needing to add layers of clothing to maintain core temperature), horses have adapted to tolerate cooler temperature by breathing less frequently. By doing this the horse will reduce the heat lost in expired breath.
Breed and Types
Some breeds have evolved to be more suited to hot and cold climates. For example, certain breeds are heavier, thicker boned, and have feathers on their legs. Warmblood breeds, drafts, and some pony breeds are more adapt to cooler temperatures. Conversely, lighter boned and leaner breeds such as Arabians and Thoroughbreds are more adapt to warmer climates.
Types of blankets
Stable Sheet – Worn inside, not waterproof, no fill, minimal warmth
Turnout Sheet – Worn outside, waterproof, no fill, minimal warmth
Stable Blanket – Worn inside, not waterproof, fill, provides warmth
Turnout Blanket – Worn outside, waterproof, fill, provides warmth
To Blanket or not to blanket
Light sheet – no fill (or up to 100 grams fill in the center)
Clipped - 40-50F
Unclipped - 30-40F
Medium blanket – 180 to 200 grams fill
Clipped - 30-40F
Unclipped – 20-30F
Heavy Blanket – 300-400 grams of fill
Clipped - 20-30F
Unclipped - 10-20F
Tips and Tricks
The Horseware® HorsePal Monitor and App, exclusively FREE with a Rambo blanket purchase, can help you understand and predict your horse's blanketing needs accurately. Using actual data, HorsePal eliminates the guesswork in choosing your horse's coverage on any given day. A small monitor inside the blanket senses and records the inner temperature and humidity. That temperature, plus local weather information, is stored in the Cloud for retrieval by the App on your smartphone. You can check on your horse's current conditions, and get blanketing recommendations based on the data and the forecast for the next three days.
I hope these blanket tips are helpful and always remember, if you are unsure, err on the side of lower weight blanket rather than heavier. It is safer for your horse to use its own natural defenses against the cold then become overheated. Furthermore, if your horse sweats under their blanket the moisture can cause chills as they cool.