Telling Tails

Navigating Your Dog’s Heat Cycle

So your darling little puppy is growing into an adolescent and along with that comes puberty.  Having “the talk” is not necessarily going to help you prevent pregnancy with your female dog so we are here to help.  There are many things to be aware of, and we aim to prepare you for all of it.

To start let’s go through the four stages of the estrus cycle and what they mean for you and your pup.


This is the most apparent stage in the cycle. – Avoid other dogs!

  • Happens for the first time between 6 months and 1 year of age, some large breeds may not start until 18 months-2 years old
  • dog in heat
    Normal vs Enlarged Vulva


    On average a dog will go into Proestrus twice a year. However, some may only go into it only once, and others may go into it quarterly

  • Enlarged, swollen vulva
  • Bloody vaginal discharge (it may be obvious blood or slightly tinted pink)
  • Your dog may be licking her vaginal area more frequently than normal
  • Male dogs start to show attraction
  • Female is not receptive to males at this time
  • Lasts an average of 9 days, but could be anywhere from 0-24 days
  • Estrogen levels will peak, and follicles will develop
  • You may see an increase in signs of stress, aggressive behavior, or sadness/depression
  • You may also see an increase in appetite


This is when your dog is fertile. – Avoid other dogs!

  • The vulva is still enlarged but softens a little
  • A decrease in bloody discharge, it may stop altogether
  • Female is receptive to males, possibly seeking them out or wanting access to outside more frequently
  • Lasts an average of 9 days, but can be anywhere from 4-20 days
  • Estrogen levels are dropping, and progesterone levels are starting to increase (Pyometra can occur as a secondary infection to hormonal changes in the reproductive tract)
  • Increase in urination/marking
  • May be more affectionate than normal
  • Carries tail high and flagging (hello boys!)
  • Willingness to stand and present vulva (tries to put her butt up against things)
  • You may see an increase in signs of stress, aggressive behavior, or sadness/depression


This is the stage where we would see signs of pregnancy.

  • Female is no longer receptive to males
  • Typically lasts for about 2 months
  • Estrogen levels are low; progesterone levels peak 3-4 weeks after Diestrus starts and drop to normal levels by the end of Diestrus- this shift happens regardless of whether a pregnancy happens or not
  • If pregnancy occurred this stage will end with giving birth
  • Pseudo-pregnancy or false pregnancy may occur (this is a serious condition that can affect your dog’s behavior wellness)


The time between Diestrus and the next Proestrus.  When your dog returns to “normal.”

  • The vulva is no longer swollen
  • There is no more vaginal discharge
  • In a healthy dog, this stage will last for an average of 4 months


While your dog is actively in the Proestrus and Estrus stages, you should avoid contact with other dogs (24 days on average).  It only takes seconds for a male to tie off with a female and they have been known to even do it through a fence.

From the first sign of heat (usually enlarged vulva) we recommend keeping your dog home and only going on adventures where she will not be able to interact with other dogs.  Even neutered males can and will attempt to mate; this should be avoided at all costs for the well-being of both dogs.  Implement a crate and rotate plan if you have male dogs in your home, or see if the male dogs can stay with a friend or family member until the entire Proestrus and Estrus stages are complete.

Tools to help you survive:

Doggy Diapers– yep this is a must-have item.  I recommend purchasing reusable ones and then inserting human panty liners (they are so much cheaper) into them.  Buy them when your pup is about 6 months old so you can start training her to wear them and keep them on.

Body harness and leash- for secure potty breaks.  If you have a fenced yard a leash is not required, however, be sure to observe every potty break in case a neighbor dog tries to get frisky.  If you feel you have access to dog-free zones for walking you can use a 6 ft. leash or a long line, whatever you feel is safest for the environment.  If you would like to try walking your dog but don’t have access to dog-free zones take her out earlier in the morning or later at night when other people are less likely to be walking their dogs. You could also ask friends and neighbors who do not have dogs if you can come and explore their yards.

Brain games- having a pent-up dog can create a lot of frustration.  Increase your indoor training sessions, add food toys (more than normal), and other food or nose work games into your dog’s daily routine.  Give them more chewy time and practice getting on and off obstacles to help tire your dog mentally and physically.

Crates, ex-pens, and baby gates- These can be used to separate dogs within the same household if needed.  They can also be used to create a diaper-free zone for your dog, this can allow her time to clean herself and get a break from wearing the diaper. Start training your dog to enjoy hanging out in these areas before you need her to do so.  I suggest giving her a food toy or special chewy while she is there to make it more enjoyable.  If you have multiple dogs, do the same chewy/food toy plan with them to get everyone used to the crate and rotate program.

Bathing- For some dogs, especially those with longer hair, I suggest bathing them once the heat is over before taking them back out in public.  This is to ensure no residual scents remain that may attract unwanted attention.

Amber Todd, CPDT-KA, UW-AAB

Owner | Trainer | Behavior Consultant

Embarking Dogs