January 2, 2018

Dr. Yates on "How Cold is Too Cold to Ride?"

Like the rest of the Midwesterners, we haven't seen the other side of 20 F in over a week and counting, so Connor has been doing a whole lotta nothin.

"...is that a problem?"

Most of our area is seeing low actual air temperatures of negative double digits as I write this, with wind chills in the 30 below zero range.  It's unusually cold even for here. 

In the interest of scientifically-researched education on the subject of "How cold is too cold to ride", my vet posted a study-backed PSA on Facebook about cold weather riding this week that some of you may have already seen: it's been shared over 4,000 times!  Thought it'd be fun to share and discuss here.  For those of you who don't know Dr. Yates, she is an eventer herself and an outstanding sporthorse vet in our area. 



By Dr. Angie Yates, DVM
I am frequently asked, and I wondered myself, about working horses in extremely frigid weather like what we are currently experiencing. It can be frustrating for all of us who are trying to keep horses reasonably fit over the winter if they are unable to be safely worked for a long period of time. I've seen this question come up on several pages today, with answers such as: just turn horses out, to ride them in coveralls with 1 of their blankets still on.
I made it my mission today to search PubMed to see if any true scientific studies have been done regarding horses exercising in cold weather. Note: this is not about hacking (walking) or horses playing in turnout. I wanted to know if actual work (trotting, cantering, jumping) was harmful, and at what temperatures.
Unfortunately, there are really only 3 studies that show up for cold weather research in horses-most of the research has been done about cooling hot horses surrounding the 1996 and 2008 Olympics.
1. Equine Vet J Suppl. 2002 Sep;(34):413-6.
Airway cooling and mucosal injury during cold weather exercise.
Davis MS1, Lockard AJ, Marlin DJ, Freed AN.
2. Equine Vet J Suppl. 2006 Aug;(36):535-9.Cold air-induced late-phase bronchoconstriction in horses. Davis MS1, Royer CM, McKenzie EC, Williamson KK, Payton M, Marlin D.
3. Am J Vet Res. 2007 Feb;68(2):185-9. Influx of neutrophils and persistence of cytokine expression in airways of horses after performing exercise while breathing cold air. Davis MS1, Williams CC, Meinkoth JH, Malayer JR, Royer CM, Williamson KK, McKenzie EC.
In the first study, scientists found increased ciliated epithelial cells in the broncho-alveolar lavage in horses that exercised in cold weather, indicating damage to the respiratory tract. This is a similar finding to studies that have been performed in cold weather human athletes, and led the authors to conclude that breathing unconditioned (not warmed or humidified) air does in fact contribute to airway inflammation in horses.
Study 2 tested horses breathing 23 degree F air at 5h, 24h, and 48h post exercise. The authors did find bronchoconstriction (narrowing of the airways) at 48 hours post exercise, and concluded that exercising in cold weather may be a cause for lower airway disease in horses.
Finally, the third study looked at horses 24 and 48 hours after exercise breathing 23 degree F air, and concluded that there were increased neutrophils (white blood cells), as well as inflammatory proteins, up to 48 hours after exercising in cold air. The authors were concerned that these findings could mean that horses were more susceptible to viral infections after exercising in the cold.
Where does that leave all of us? My decision after viewing the literature today is that I'm going to avoid true exercise (cantering/jumping) when the temps are below 20 F. We really need more studies done in a natural environment (outside, not using treadmills) in colder weather for more information, but there is enough scientific evidence currently to show that at least some damage is done to the respiratory tract at temperatures 23 and below.-Dr. Yates
*********Edited on Dec 30: I posted this in the comments but it's buried at this point, so I wanted to move it up here:*********
I wanted to jump back into the conversation to clarify some of the questions that have been asked and debated. First, I want to ask people to please be respectful of one other. Some of these debates have become overly contentious.
Secondly, since this post has now been seen over 400K times in different parts of the world, I wanted to reiterate that the original intent was to get guidance on sport horses (h/j, dressage, eventers) WORKING (NOT trail riding or turned out) in the Midwest USA/Great Lakes region. For those not familiar with our weather, we tend to have wild temperature swings in the winter, where it may be 30 deg F, but then have 2 weeks of 10 deg F-minus 0 temps. Our horses are most assuredly NOT acclimated to extreme temperatures, but the question always arises if it is too cold to ride.
Many people have mentioned racehorses/Amish/working ranch horses. I'm very aware that there are many northern tracks that race in the winter, as well as ranch horses and Amish buggy horses that continue to work cattle and drive their families to town. It would be interesting to scope and do serial BALs on those horses to determine if their cytokine/neutrophil levels match these studies or are significantly different.
Finally, several people have asked for the specific materials and methods for the studies. I don't have the full text of the first 2 papers, but the M and M for the third is as follows: 9 adult horses (no breed mentioned) trained on a treadmill 3 times/week for 12 weeks. The exercise test was 5 min walk at 1.8 meters/s, 5 minutes trot 4 meter/sec, and 5 minutes canter 6.8-9.5 meters/sec. The samples were collected at 24 and 48 hours post exercise test.
Thank you to everyone for the great discussion!

29 comments:

  1. For the sake of all parties involved, I won't ride under 20, and don't do a whole lot under 25. I think I saw this same study last year, and was glad to see I was pretty in line with the recommendation.

    We've been having a bit of a cold snap too, but nothing like you guys! I hope it warms up soon!

    ReplyDelete
    Replies
    1. Me too, doesn't look good for that though. We're supposed to get to 20 one day and 33 the next before going back down into this sub 20 highs/subzero lows crap. Sigh.

      Delete
  2. Thanks for sharing. I school down to 15 (but lightly) and will get on bareback down to 10. We turn out pretty much no matter what. (Not sure what they did in -21 this morning!) I used to school down to single digits, but adjusted that upward as Tristan got older.

    It's really useful to see some actual scientific research, so thanks!

    ReplyDelete
    Replies
    1. I've always been pretty well in line with what you do, I'll hop on and putz around at the walk at 15, but not do much else. And, that's still right in line with what Dr. Yates is saying. Definitely seems like we need some more studies on it though.

      Delete
  3. That's cool the article was from your vet. I saw it on Facebook last week. A vet I used to board with said the same thing, so nice to see that advice is consistent!

    ReplyDelete
    Replies
    1. That's funny, I had no idea it had been shared that much until I got the idea to post it here and went back to copy/paste it. Yeah, it seems reasonable to me, just nice to see someone trying to dig up actual research on it instead of anecdotal wives' tales.

      Delete
  4. thanks for sharing that link - very informative! our extreme cold weather here right now has kinda got me thinking a little more deeply about the subject, actually, and i think i might write a post on it too. it is definitely possible to ride in extreme cold weather without harming your horse, so long as you are thoughtful in how you do it. research like this is so useful in better understanding what that means.

    ReplyDelete
    Replies
    1. I completely agree with you, you can definitely do it safely and still be productive, you just have to be smart about it. I personally take it as a chance to work on walk, halts and suppleness, although it's been too cold here for me to even think about riding, with highs in the single digits. :-\ I'll be interested to see what you write!

      Delete
    2. This comment has been removed by the author.

      Delete
  5. I'm always amazed at how you all handle the cold weather. It gets down to the low 30s here and I can't handle it. Too cold. I couldn't imagine even wanting to be outside at 20 degrees, certainly not riding lol

    ReplyDelete
    Replies
    1. 20 would be a welcome warmup right now, lol! It really is all about having the right clothes for it. I went out to see Connor and pick his feet out at 3 above last night and it took me 10 minutes to get dressed in all my layers, but I wasn't uncomfortable.

      Delete
    2. I'm so jealous, the 10 degree high that we got today felt positively warm compared to the last few days where it never got above -4ish.

      Delete
  6. Her post was shared on my barn's Facebook page prompting some discussion. Much of this discussion made it abundantly clear that no one read the entire post... frustrating, considering I thought Dr. Yates was extremely careful and thoughtful in her word choice. Variables are important! As with other horse care topics, the review of current studies should help guide owners into making their own decisions for their own horses. I hope her post pushes others in the field to consider more research on the topic!

    As for my opinion: If I factor in my riding environment (indoor arena) and use some common sense (longer warm-up/cool down and minimal cantering/not working up a sweat) then I would ride in 0-20 degrees. That said, I enjoy riding significantly less when it's under 20 so I do it significantly less!!

    My old barn in MN posted that lessons would only be cancelled if actual temps at the time of the lesson were below -5. Their indoor arena always measured 20 degrees warmer than outside temps and you could leave out windchill as a factor inside as well.

    ReplyDelete
    Replies
    1. Yeah, like anything in the horse world, even carefully chosen science-backed opinions on this stuff will cause ruffled feathers. I think her post made it clear too that your MN lesson horses were way more used to this weather than our Indiana-based horses who are not acclimated to it. Same for heat - I train regularly at 5pm on hot days, so I don't mind taking a 95 degree lesson, but if I never rode in 95 degree weather, that would be a lot more taxing on Connor's system.

      Delete
  7. I read that post when you shared it - it's still super interesting. When it's under 20, I like to keep the work quiet (there's lots to do at the walk and trot!) and short (if I've lost feeling in my toes, it's time to wrap it up). Penn has started acting up a bit and getting silly with all the time off, so I've been long lining him for 20 min or so at the walk and trot when it's been single digits. I'd prefer to wander bareback, but he's reverting to being silly and spooky!

    ReplyDelete
    Replies
    1. Oh Penn, lol. Yeah, I agree with all that. I tend to loose feeling in my feet especially quickly, so every trip of 30 minutes+ to the barn right now I'm wearing whole-foot foot warmers, which helps. Long lining is a good idea, then you're both moving instead of just one of you.

      Delete
  8. Thanks for sharing. I always like to see research backed advice.

    That said, I think her note about the advice being for horses who are not acclimatised to the temps is important. Here in Alberta we get a whole lot of days below 20F and if I used that as a cutoff I wouldn't get to ride for months! (unheated indoor arena)

    My personal cutoff (and the one used by 4-H clubs here) is also 20, but -20C (-4F). Below that I will still go out, but keep it to low intensity and walking exercises instead of real work. I also try not to haul below -20C. It got down to -38C (-36F) here on Dec. 31st though and that's too cold even for here. The last time I was at the barn I almost froze my hands just trying to pick feet! =P

    ReplyDelete
    Replies
    1. Yeah, that's an important distinction. Mammals are really good at adapting to extreme temperatures, but they have to have that time to adapt. And if you're not used to cold/heat/humidity/whatever, it's harder to perform than if you were adapted.

      Delete
  9. As a californian I've never considered this (Where my horses lived it was more 'how hot is too hot to ride')

    ReplyDelete
    Replies
    1. I can see that. And with horses really being cold weather animals, heat is more dangerous than cold.

      Delete
  10. Thanks for this post, it's good to see the research. And it reminded me to text my trainer to ask if we're lessoning tomorrow! My barn is INCREDIBLY lucky to have a heated indoor, but I worry about my lesson horse not being cooled off before she goes back to her unheated stall.

    ReplyDelete
    Replies
    1. We had a heated indoor in college, it was FANTASTIC. In this part of the country, everyone has indoors (requirement!) but no one has heated indoors that I know of.

      Delete
  11. I typically don't ride below 10 degrees in the arena but when ride and it's 10-20 I typically do a TON of walk to warm up and keep things pretty easy. I also really limit how much cantering I do. I'm lucky to have a heater in the arena that will being the temp up a few degrees but since it doesn't stay on it doesn't normally bring the temp up that much.

    ReplyDelete
    Replies
    1. That makes sense. You're also probably in a part of the country where she's more acclimated to it than Connor is, where it gets cold, but not this brutally cold very often.

      Delete
  12. My riding bestie met Dr. Yates in Southern Pines a couple years ago (or maybe last year) and shared her article too! Finally, studies!!!!!

    ReplyDelete
  13. Hampton will never have to worry about being worked when it is too cold or dangerous for him because I wimp out fairly quickly at around 15 degrees. Sometimes 20 degrees. Just a big fat nope from me.

    ReplyDelete
    Replies
    1. Yeah...I am increasingly that way myself. It's going to be 21 today and I still probably won't ride.

      Delete
  14. I saw this! Thanks for sharing again, I thought it was a really great post.

    ReplyDelete