extreme heat and early pregnancy

My vet confirmed that my mare is pregnant the other day via ultrasound. She is 15 days in from the initial breeding. Since then, the heat has been extreme here in Pennslyvania. Should I worry about her losing the pregnancy from the extreme heat? She has shelter, fans and is hosed down during the hottest part of the day but it is still pretty hot in the barn. She does not looked stressed and seems to be tolerating the heat but I am still worried since we are just in the beginning stages of her pregnancy. And July is just getting started…

Of course you should worry, that is par for the course with breeding! That said, it sounds like you are doing all you can to prevent it. I would be more worried about having a newborn in this heat, I know someone who lost their foal recently despite their vet’s efforts to keep him cool enough. Hopefully it won’t be this not next summer.

This weather is why I clip my foals! So happy to have done it before the derecho hit and we lost power for 5 days! I did have a foal land at Marion duPont Scott Equine Medical Center the summer of '08 when it was so very hot. He was okay, but no doubt his symptoms were heat related! I think all developing black dots are safe as long as the mare is not ill herself.

Diane Halpin: Facebook
Laurel Leaf Hanoverians: Facebook

If it is hot next summer, take the little guy and his mother into the air conditioned house! (I have a friend who did that…)

Diane do you have to sedate them to clip? One of mine is not shedding at all yet, and I worry about the heat and the length of coat he’s carrying. I have never contemplated clipping before, but our temps have been super high, with not much relief in sight.

[QUOTE=sixpoundfarm;6426880]
Diane do you have to sedate them to clip? One of mine is not shedding at all yet, and I worry about the heat and the length of coat he’s carrying. I have never contemplated clipping before, but our temps have been super high, with not much relief in sight.[/QUOTE]

We don’t sedate ours. We get them used to clippers early on and it usually is no problem to clip them. My daughter usually does it by herself in the stall with cordless clippers.

I’ve been worrying about the pregnant mares with this heat too.
(although as Laurie said, worry is what we do.:wink: )
They do not seem in any distress though.

There IS risk in losing an embryo this early in high heat.

http://www.equine-reproduction.com/articles/EED.shtml

Recent research (2007) demonstrated a lower embryo recovery rate from mares exercised daily for 30 min under average ambient conditions of >30° C and >50% humidity when compared to non-exercised mares (34% vs. 63%). This suggests that an increased core temperature brought about by exercise under such ambient weather conditions during the early embryonic period may negatively impact embryo survival.

[QUOTE=JB;6427013]
There IS risk in losing an embryo this early in high heat.

http://www.equine-reproduction.com/articles/EED.shtml[/QUOTE]

No, not a risk because of hot weather, but a risk if the mare’s core temperature is elevated. So it really depends upon the mare’s behavior, etc. You can easily have broodmares outside in extreme heat (like what we are experiencing) and not have a rise in core body temperature. That study was 30 minutes of exercise, so obviously I wouldn’t ride a pregnant mare in this heat, nor would I want a dog chasing her around, etc. but normal activity is probably fine.

True, that study was done with exercise involved, but as you said, it’s about the core temperature, and while it’s certainly not as big an issue with some mares, others don’t handle heat well and could have problems.

This. :yes: Whenever we do an ET with my mare Stanza, she gets a light week form breeding to flushing because of the danger if her core temp gets high. That is a given in strenuous dressage training in FL in the late spring into summer. I don’t worry as much with my mares who are not in training, but they are pretty placid ladies and have plenty of shade and shelter.

After my mare was bred and checked in foal at 15 days at the clinic, I planned on shipping her home, which is about an hour and one half drive. Her repro. vet was adamant that she be hauled in the early morning because of the risk of rise in her core temperature on a hot day, which could happen hauling in the afternoon if she became stressed.