How to tell if mare is in heat?

If mare doesn't pee all around, and teasing is not an option how definitely one can say if it's in heat?

Good question! I've often wondered that too. I never know when my mare is in heat either because she doesn't act marish either. Sometimes when I clean her stall it's super messy (manure all over and paced through and a really big pee spot) and not in it's normal order, and during that same time period I sometimes notice a little bit of dried stuff underneath her tail when I'm hosing off so I assume she is in heat during those times but I don't really know. Anyone else?

I had a mare that didnt pee neither, but she would wink and there would be dried stuff on her rear end..that's how I knew.

Honestly, kitten, without a teaser (even a gelding with attitude?) the only way I can think of to know for sure is to have a vet palpate her.

Peeing/winking/squealing/attitude changes just aren't reliable enough indicatiors.

Some mares squirt and wink all summer long; some mares have to be worked over and courted by the teaser for 10 - 15 minutes before they show any sign.

Thank you, ladies!

Why I asked I noticed my paint gets extremely nervous and touchy every month. And I'm guessing if it's "in heat" period. I started calendar last month to see when it'll be again. For about 3 days she's VERY hard to work with. But she doesn't squirt, or pee, or does other "non usual" stuff. BTW with my other girl she randomly has a bad mood, but it's not something periodic (at least I didn't notice).

So the normal cycle is 28 days if I'm not mistaking. Do they have deviations (like women)? I mean can it be 30 days or 20 days in between?

Yes, there can be lots of deviations. And I had a mare whose sides would get extremely tender and sore during her heat periods. Three weeks of the month, you could put your leg on her; do whatever you wanted. One week of the month, she pinned her ears and wrung her tail any time you asked for a canter or lateral movement. She'd even get pissy about being curried or groomed hard along her flanks during this time. When the vet palpated her prior to breeding the poor thing went nuts.

So "nervous and touchy" doesn't seem unreasonable to me as a symptom of heat if it fits the timeframe.

The typical cycle is in the 20-23 day range.

Also, girls are starting to transition into winter anestrus right now so cycles are wonky and all over the place, you probably won't be able to characterize her heat cycles well this time of year.

Would being hard to catch be another possible symptom?

Or something else entirely?
The mare I lease will come up no problem normally but lately she's been a bit of a pain to catch, and I've noticed her sides are a little tender too.

Hmmmm.... Interesting. With her it seems to be every month end of the month - beginning of the month. At least I had it beginning of April, beginning of July, and Aug 28 - 30 (for some reason I remember Apr and Jul, but not sure about May and Jun). I'm betting on the end of Sept now.

BTW, hard to catch never was an issue to me. Usually brushing is not a problem too, it's her getting alert to the extreme about everything (familiar things including) and somewhat touchy to the leg when riding.

So are there any cure to make them feel better? Does it make sense to just leave her to herself for those several days? I keep working her those days, it's just not fun for either of us.