What her cycle does to her behaviour
Mares come into season roughly every three weeks through the spring and summer, and for the few days she is in season her hormones genuinely rearrange her priorities. Owners describe the same cluster of changes: squealing and striking out when other horses come close, then flirting outrageously with one particular gelding; frequent small urinations and tail-raising; sensitivity when groomed over the back, loins and flanks; distraction under saddle, a reluctance to concentrate, and sometimes a mare who feels as though she has gone tight or tender through her back. Between seasons, the same horse is level and businesslike — which is exactly why the change catches people out in the first year they own a mare.
Handling that adapts without lowering standards
The skill is to keep the rules and soften the delivery. She still leads politely, stands to be groomed and respects your space — manners are not suspended for the week — but this is not the moment to pick a fight over a new exercise, drill a movement she is finding hard, or read her protests as defiance to be punished. Quieter handling, a slightly shorter schooling session and patience at the mounting block achieve more than insistence. Be thoughtful around other horses as well: a mare in season can be magnetic to geldings and irritating to other mares, so give everyone a little extra room at the mounting area, in the wash bay and at the field gate.
Work, turnout and company through the season
Most mares work perfectly well through their seasons once the people around them adjust their expectations; a few are genuinely uncomfortable and do better with lighter work for a day or two, which only becomes clear once you have tracked a couple of cycles. Keep her routine as normal as you can — routine itself is calming — and note the details that repeat for her: the day the squealiness peaks, the exercise that bothers her, the companion who sets her off. Turnout combinations may need a temporary reshuffle if she is stirring up the field, and that is management, not failure. Each cycle teaches you something, provided somebody wrote it down.
When a vet check is worth booking
Most seasonal behaviour is normal, but some of it is pain wearing a hormonal disguise. Book a vet visit if the behaviour is extreme, if she becomes aggressive in a way that is out of character, if her seasons seem continuous or unusually frequent, if she shows discomfort such as kicking at her belly or repeated straining, or if the sensitivity under saddle is new in a mare who has always been even-tempered. Ovarian and back problems both announce themselves through 'seasonal' behaviour, and a mare who is suffering deserves an examination rather than a reputation. Tracking costs nothing but attention: note her season dates and handling notes in KinsLe through Care Teams, and whoever leads, grooms or rides her that week knows where she is in her cycle before they pick up the rope.