Heat Cycles – What to Expect

Zora finally went into her first heat.  I chose to let her go through at least one heat cycle before spaying due to the benefits shown by more recent studies that looked at hormones, growth patterns and long-term health benefits.  I have no intentions of breeding her (in fact I’m going to great lengths to avoid that). Contrary to what some people believe and what older, outdated information may say, there is NO BENEFIT for your dog’s health to letting her have a litter of puppies before spaying.  Any perceived benefits were likely due to letting the dog go through a heat cycle and avoiding a pediatric spay.

On average, female dogs will go into their first heat around 6 months of age, although depending on size and each individual, heat cycles can start anywhere from 4 months of age to 24 months. 

Heat cycles are made up of 4 main stages – Proestrus, Estrus, Diestrus and Anestrus.  The main phase of the heat cycle typically lasts 20-30 days, but depends on each individual dog.  First cycles are often less intense than following cycles.

Proestrus starts with swelling of the vulva and red/bloody discharge.  How much will depend on your dog’s breed, size and individual body.  Larger dogs can bleed more than smaller dogs.  This phase usually lasts around 7-10 days.

Estrus is the period of time when your dog is most likely to be receptive to mating and when they can become pregnant (although dogs have been known to become pregnant through different stages of the heat cycle as well).  She may seek out males to try to mate.  This phase also lasts around 7-10 days.

Diestrus is the period of rest after Estrus. There may or may not be additional swelling of the vulva and discharge. This phase often lasts 7-10 days (or longer if she becomes pregnant).

Anestrus is the final phase and is the period of time between heat cycles.  This can last anywhere from 5-9 months.  During this phase your dog should have no swelling (although nipples may become a little larger after the first heat) and no discharge.

You can help your dog by continuing all of their normal activities, providing additional walks and enrichment, adding absorbent cloth materials to their bedding and ensuring they are closely supervised with all dogs during their heat cycle.  Even neutered males may give unwanted attention and though rare, may cause injuries through attempted mating. 
You will need to take a break from taking your dog to dog facilities (other than the vet if needed), dog parks and off-leash dog trails.  She should NOT be around un-neutered male dogs during this time.

Supervise your female or keep her secure and indoors when you cannot actively supervise her.  You will need to manage her environment and which dogs she has access to for a full 30 days.  Note that dogs have and will breed through kennels and fences.  They are also notorious escape artists (males and females) when there’s a breeding opportunity.

You may also want to restrict your dog to easy-to-clean areas and/or get some cloth doggy diapers for her to wear.  The diapers help with mess and also help to prevent pregnancies (though that’s not enough protection from a persistent dog).  Give your dog breaks from the diapers if you use those since they can make your dog more susceptible to UTIs.

Your dog’s behavior will likely change during her cycle.  She may become more aloof, more cuddly, want to play with other dogs, want nothing to do with other dogs, more whiny, restless, snippy or have a variety of other behavior changes.  Remember, physical health affects behavior!

For more information about the heat cycle, consult with your vet and/or find some good breeders to talk with about their experiences.  Personally, I've found it more informative and helpful to listen to/chat with seasoned, ethical dog breeders.  It's been fascinating to learn their stories and see how different each of their breeds and individual dogs behave and go through their cycles.
You should also educate yourself on the risks and benefits of keeping an in-tact dog and if that's something you are up for and responsibly able to do.