[JSO]

I have a 28 year old standardbred mare who I've owned for about 14 or 15 years. She is retired and in good body condition, not heavy but a 5/9 condition. She actually looks amazing for her age!
This morning was one of the coldest mornings this fall and the low for the night was 36 degrees. She is typically turned out 24/7 on grass or in a large (20 x12 stall) with attached paddock. She was in the stall/paddock overnight last night w/ free choice hay and when I went to feed breakfast at 8am she was shivering all over. She seemed agitated and I put a blanket on her and she stopped shivering after a few minutes but seemed bothered when I would touch her belly or flank ( would pin her ears, try and bite... very unlike her!) She had plenty of manure in her stall, no signs of colic and gobbled down her breakfast and has been fine all day.
I was just very surprised that she was cold when it wasn't that bad. She is a little bit fuzzier than my other horse who was completely fine. In the past she has started shivering in damp/ cool weather if she wasn't sheeted whereas he would be fine so I know she is less tolerable to cold.
Over a year ago she had an episode on a damp summer morning where she was shivering and we thought it was more muscle twitching than shivering. It lasted a few days on and off and was pretty mild. Bloodwork was all normal and she stopped and it didn't happen again so we never further investigated it. At the time she was completely fine otherwise. I felt that this morning it was more of a shivering from being cold not so much as a muscle twitching.

FYI: She has mild cushings disease that we haven't treated since she hasn't shown much for signs and her levels haven't changed in the past 5 years.

Any ideas? Is it common in older horses to be THAT intolerant of the cold? I feel like by the time winter rolls around she is going to need to wear 5 blankets!!! In the past she's only ever been blanketed in extreme cold or wet weather.

p.s. I'm also a vet (newbie) myself and couldn't find much other than hypothyroidism as causing cold intolerance in horses so I'm picking all you smart horse owners' brains!

Thanks!

[Marla 100]

I've noticed that with Old horses, Old dogs and Old humans, they lose their ability to regulate their body temps and react to cold weather much more than their younger counteparts.

My friend's 34 yr. old TB would need to be bundled up in winter to stay warm and not shiver. This was inside a barn and in Florida.

The elderly body is just not efficient at keeping warm.

[rabicon]

My 34 and 36 year olds got blankets on when it was 40 or under. Even though they were in great shape maybe a little fat lol they would still shiver and be cold. It seems as they get older they just can't warm up as easily.

[marta]

cushings horses have a harder time controlling their body temperature.
i assume you have her tested annually to verify her ACTH levels are within norm? although i really don't understand what that means that she has cushings but that you're not treating it b/c she "hasn't shown signs." what signs are you looking for? elevated ACTH is THE sign. i don't get it. are you waiting for her to grow the cushings coat before you actually give her the benefit of available treatment?

[deltawave]

First time it hits 30 degrees here in the fall I'm shivering. But by the time winter's over, the first day where it gets UP to 30 degrees I'm outside in a T-shirt.

Adaptation takes a little while. I wouldn't be too concerned if she warmed up promptly. Throw some extra hay and be vigilant, but the first few cold days require that everyone do some adjusting of the thermostat.

[SAcres]

My 20 yr old TB definitely is less tolerant of the cold than he was when he was younger. More than once I've come to the barn to find him shivering. I do try to leave him unblanketed as much as possible, but unfortunately that means sometimes I don't get to the barn before a cold snap or it starts raining.

[superD]

My 18 yr old gelding needs to have a blanket on in anything under 60*!!!!

He does at times need to have 5 blankets!!

[rememberthenight]

My 12 year old arabian mare (seemingly very healthy, and round as a barrel) has been shivering the last few mornings that we have had 35-45F nights. She however has always been this way, and shivers in warm rains. I find once she gets used to the cool weather she is just fine, but the 75-80 days and cold nights really throw her system off. I just started sheeting her, even though she is naked most of the winter once the weather stabilizes.

[HealingHeart]

Agree, this is why our grandparents wear sweaters in warm weather

I've noticed that with Old horses, Old dogs and Old humans, they lose their ability to regulate their body temps and react to cold weather much more than their younger counteparts.

My friend's 34 yr. old TB would need to be bundled up in winter to stay warm and not shiver. This was inside a barn and in Florida.

The elderly body is just not efficient at keeping warm.

[SuckerForHorses]

First time it hits 30 degrees here in the fall I'm shivering. But by the time winter's over, the first day where it gets UP to 30 degrees I'm outside in a T-shirt.

Adaptation takes a little while. I wouldn't be too concerned if she warmed up promptly. Throw some extra hay and be vigilant, but the first few cold days require that everyone do some adjusting of the thermostat.

This. Both of my horses were shivering on the morning following our first cold night (30's). They are out on pasture, grass available all the time. By sunup, they were not shivering, and haven't since even when the temps have gotten back down to near 30s. It takes a bit, but they do adapt after a few chilly nights. My mare is 20 and my gelding is 6.

[fooler]

Some horse are like my old instructor and my husband-they don't tolerate cold backs well. We also had several horses in the barn that were sheeted in 50-60' and blanketed at 30-40's. All were geldings who presented with severe colic symptoms that were gone once they were sheeted or blanketed.

So it sounds, to me, like your mare had a very cold back and it took some time for the muscles to completely relax. Get the vet out for a once over and you mentioned Cushings. Watch her as she may now require a sheet or blanket or more hay. We all lose subcutaneous fat as we age and so are unable keep as warm as when we were young. Something to say about 'baby fat'

[Dressage_Diva333]

Anything below 50 and my 11yo Arabian mare is blanketed. She would always drop weight like crazy going into winter.... I usually start blanketing the others around mid-November off and on.... This particular horse has to be blanketed usually EVERY NIGHT starting mid October. When I figured out she was just THAT cold, her weight has held well... and we DO NOT have severe weather out here in California! It rarely get's below freezing here.

Listen to your horse, if she's shivering, blanket her now When my 49yo gelding was alive he was about as high maintenance as my mare, I ended up getting him a lightly filled blanket and just layering as need be.

[Tom Bloomer]

I think I look good for my age, but I shiver at 70F and get frost bite at 60F.

[rcloisonne]

You say all bloodwork was fine but what was actually tested? T3 & T4 (and possibly, free T-4) are not usually part of a routine blood screening panel.

Although primary hypothyroidism has never been documented in equines, Cushings disease can cause the thyroid gland to under produce needed hormones. Many Cushings horses are treated with levothyroxine (Thyro L) along with other drugs. That your mare showed signs in addition to shivering (didn't want you to touch her) also points to an under preforming thyroid.

I'm also not understanding what you mean by "mild Cushings". How was this diagnosed?

[betsyk]

Think about this, too: they are just starting to get their winter coats. In a month, they'll have a lot more hair! in two months, they'll be well on the way to looking like yaks and they'll sweat when it's 60 degrees.