Can horses thrive in the cold?

We have had some very cold temperatures in Leicestershire with a covering of snow that froze to the ground a week ago, today Jan 12th is it starting to slowly melt away. The days have largely been sunny and bright, but the fields and arena frozen, the concrete slippery and the roads varying from lethal to normal depending on the time of day.

Absolutely YES, horses with nature's fluffy winter coat adapt splendidly to cold, calm weather!

Windy and wet weather, even if temperatures are higher can chill them. In this case, given the choice they will want to seek shelter in a barn or stable. In fact horses create heat and then preserve it better in a cold snap than they can dissipate heat on a very hot day.

Here is the science! Horses are homeothermic or warm blooded, keeping their core temperature within a narrow range as the temperature around them varies. But thermoregulation is complex and depends on slowly adapting as temperatures drop as well as age, breed (which in turn determines type of coat and skin thickness), body condition, feed and overall health.

The study of horse's behaviour can give us some valuable clues. A large study in Belgium (426 horses) at ambient temperatures of -4 to +37 Celsius who had free access to a shelter used this most frequently when temperatures dropped below +7 ( particularly where there was also rain) and above +25 (particularly where there were high insect numbers).

In cold temperatures heat production leads to an increase in appetite and this is most efficient when long forage is eaten compared to concentrates.

Bertie at dawn around -7 celsius ad lib forage and access to a shelter. Not clipped but rugged with under blanket as he is an older TB x gelding. His companion is present but out of the picture.

Cold blooded (heavier breeds) have more protective mane and fetlock hair, thicker skin, develop a thicker winter hair coat and more easily build up fatty reserves.

Young (yearlings and older) growing, fit working animals, together with lactating mares have a higher metabolic rate and generate heat more readily than say a retired gelding.

So what is a "comfortable" lowest temperature? Published results varied from as high as +10 to as low as -16 Celsius! Active shivering of the muscles has sole the purpose of heat generation and is an indication of the animal needing to take active steps to maintain homeostasis. Or, put another way, they are too cold. Again we need to be careful. Acclimatised Icelandic horses (living out unclipped) experiencing temperatures down to -30 Celsius shivered only once when temperatures reached +5 Celsius in heavy rain.

On a hill so bare it could use a hat, we keep our eyes peeled like bananas when the thermometer dips below a balmy 5 degrees (or skyrockets above 25 degrees) Celsius, especially when the wind's howling and the weather's throwing a tantrum with rain, sleet, or snow.

Horses will aggregate together, turn their backs to the wind, tuck in tails and move around to keep warm, seek a more sheltered spot or stand in the sun. A horse that can move with his companions will be warmer, fitter and happier. His joints will be more supple and less prone to swelling, especially in the lower limbs.

Herbie and Bertie tucking in to steamed hay.

At maximum efficiency the energy used by the muscles produces 25% work and 75% heat,

Yes you did read that correctly!

And so we come to rugging... that most thorny of issues and as you can see mine look like daleks at the moment.

Herbie is that cold blooded horse we talked about earlier, but he is also a cross - with TB blood hidden away. he is fully clipped and HATES the cold and particularly the wet. He has a light weight outer rug and warm duvet underneath. Bertie, a TBX unclipped but with little natural coat, is in a heavy duty turn out and lighter under rug. He is less emotional about a drop of rain, but his feet hate being too wet producing monster abscesses and so to prevent that awful pain he is stabled in very wet weather, day or night. I aim for a minimum of 12 hours turn out for him and Herbie is not stabled at all, (more of that in the next blog). There are occasions where constant rain means 2 or more feet-drying-spells in a 24 hour period are needed for Bertie.

Clipping and the use of rugs do interfere with natural thermoregulatory processes with rugged horses less able to lose heat through vasodilation once the sun comes up and the ambient temperature rises. Ill fitting rugs can be uncomfortable or even cause sores. All rugging should be checked daily and rugs changed regularly.

One study tested the preference of horses for wearing a rug. At +6 degrees on windy rainy day, 100% of horses asked for a rug. But in moderate conditions there were marked individual preferences....

My take home messages - turn out in cold or even very cold dry conditions with the choice to move around and seek shelter, good plentiful forage and a companion or two SHOULD benefit all our horses. But we are not wrong in making choices for our own animals based on yard constraints, individual personalities and preferences, age breed and physical condition.

Do you like to read the research? Look at the October 2020, (Volume 231), review in Applied Animal Behaviour Science, " Caring for the horse in a cold climate. Reviewing principles for thermoregulation and horse preferences." Mejdell C M, Knut E B, Jorgensen G H M.

Did you know, even stabled horses can exercise. Worried about their physical or mental well being where you cant realistically turn out? Step by Step Physio can help, give us a call or drop me a WhatsApp. for a no obligation chat.