A breeding plan runs on dates, and memory is a poor substitute for a written log. A heat cycle has stages that look similar from a distance and mean different things to your vet, so the value of your notes lies in recording what you actually saw, on the day you saw it, in words plain enough for someone else to interpret months later when a due date or a missed cycle is being judged.
What to record as the cycle starts
Note the first day you observe the early signs: vulval swelling and a bloody discharge are the usual opening markers of the stage when males become interested but the female is not yet receptive. Record the date, what the discharge looks like, and any behaviour change such as restlessness, clinginess or reduced appetite. Add practical notes too — when you started using hygiene pants, whether other dogs in the home are unsettled — because the household picture helps your vet understand the timing you are describing rather than guessing at it.
Tracking the shift into the fertile days
As the cycle progresses the discharge typically lightens in colour and your dog may begin flagging — moving her tail aside and standing — which signals the receptive stage your vet cares most about for timing. Log the day that shift happens, each mating date if breeding takes place, and the identity details your vet and the stud owner agreed to record. If your vet uses blood testing to pinpoint ovulation, write the results into the same log against their dates, so the numbers sit beside the signs you observed rather than in a separate thread of messages.
Building the due-date picture
From mating and ovulation information your vet will estimate a due window; write that window at the head of a fresh page in the log and work backwards to note when to start closer observation. Record appetite changes, nesting behaviour and any temperature readings only if your vet has asked you to take them, noting the time of day so readings can be compared fairly. If the due window passes with no labour, or signs appear well before it, that dated log is what lets your vet decide quickly whether to examine her rather than relying on your recollection under stress.
Keeping the log honest and usable
Write entries the same day, keep the wording observational rather than interpretive — what you saw, not what you concluded — and never tidy up earlier entries with hindsight, because a corrected log can hide the very pattern your vet needs to see. After the litter or the missed cycle, add a short closing summary: what the cycle taught you about her normal pattern, her typical cycle length, and anything to watch next time. Over two or three cycles those summaries become a genuinely useful picture of this individual dog. Record also how this cycle compared with her previous ones, since a departure from her own established pattern is information your vet will want when judging the next season.
A breeding log earns its keep by being boring, dated and complete, and KinsLe's Pet Passport keeps those cycle records together with her wider health history in one packet your vet can review at a glance.