How Long Does a Jack Russell Stay in Heat?

By John Martin - May 4, 2022

Jack Russell sitting in nature

If you’re an owner of a female Jack Russell and are wondering about your pet’s heat cycle and how long it will last, in this article we’ll deep-dive into all that there is to know about the topic. So, keep reading…

Heat Cycle of the Jack Russell

Your female Jack Russell will be in heat or estrus usually every 6 months from the time she is 6 months old, until the end of her life. A female Jack Russell Terrier’s heat cycle lasts about 21 days on average. The female is most receptive to mating and is likely to breed during these 21 days.

The female Jack Russell can have up to two heat cycles every year. Typically, the heat cycle of a female Jack Russell Terrier has 4 phases:

  • Proestrus: This is the 1st phase, which lasts for around 7 to 10 days.
  • Estrus: The estrus phase typically lasts for around 8 to 10 days.
  • Diestrus: The 3rd phase known as the diestrus phase typically lasts for around 56 to 68 days.
  • Anestrus: The final phase or the anestrus phase lasts for around 60 to 100 days.

It is important to remember that these are the 4 phases that a female Jack Russell that has not been spayed goes through during a year. These four stages do not represent the entire heat cycle of the dog.

The heat cycle comprises just 21 days, during which time the Jack Russell is most likely to reproduce. This implies that the female Jack Russell is constantly in one of the four heat cycle stages throughout the year, but the one you are most familiar with occurs within the 21-day window.

Many changes occur in your pet’s body as a result of hormonal changes, including bleeding, discharge, an enlarged vulva, frequent urination, and heightened alertness or agitation, all of which indicate that your Jack Russell is in heat.

She will also raise her rump and hold her tail off to the side while approaching male canines. The important thing is to understand when your Jack Russell Terrier is in heat and what you can do to help your pet when she’s going through the cycle.

At What Age Does a Female Jack Russell Go into Heat?

Typically, a female Jack Russell Terrier has her first heat cycle when she’s around 6 to 9 months old. This is usually followed by a 2nd heat cycle around 6 to 7 months after the first cycle. The female Jack Russell generally has 2 heat cycles in a year.

Because your pet has not achieved full maturity and her eggs are not developed, it is recommended not to breed your young female Jack Russell Terrier during her first and second heat cycles.

Signs That Your Jack Russell Is in Heat

Some of the signs that your female Jack Russell is in heat include:

  • The most obvious sign that your Jack Russell is in heat is a swollen vulva. Your pet will have some bleeding and there may be some straw-colored discharge. You may notice your pet licking her genital area excessively.
  • When your Jack Russell is in heat, the estrogen levels increase and then there is a sharp decrease. When the estrogen levels fall, the ovaries release the eggs. Your dog may be moody, cranky, irritated and even hostile toward other dogs during the proestrus period, or the first phase of the heat cycle. She will become flirty with male dogs when she enters the estrus period, which occurs around the 11th day of the heat cycle.
  • When your female Jack Russell is in heat, the vaginal secretions, as well as urine contain hormones and pheromones, which attract male dogs. The female dog tends to urinate more frequently when in heat. She may mark objects when on a walk or on things around the home to attract male dogs.

How Long Do the Heat Cycles Last?

Your female Jack Russell will be in heat from around 2 to 4 weeks on average, although the duration may be shorter or longer. Although certain breeds are receptive to male dogs throughout the heat cycle, your Jack Russell may not be receptive to male dogs in the early stages of her heat cycle.

You will know that your pet’s heat cycle is over when she is no longer bleeding or having any discharge and her vulva returns to the normal size. Even throughout the heat cycle, your female Jack Russell has a very narrow window when she is most fertile.

The fertile period typically begins 9-10 days after your pet goes into heat and lasts for around 5 days. But your Jack Russell can become pregnant until the end of the cycle.

Also Read: How Do You Discipline a Jack Russell?

Is Estrus in Female Jack Russells a Lifetime Thing?

Once estrus starts in a female Jack Russell Terrier, it can take some time for the cycle to become regular. In some dogs, the process can take up to 18 months to regularize and so it may be a good idea to monitor your pet’s heat cycles and keep a record of them in the early days.

Once the heat cycles regularize, they may occur once in 6 months on an average. Generally, smaller breeds may go into estrus more frequently i.e., as often as 3 to 4 times in a year compared to large dog breeds that may go into heat once in 12 to 18 months.

As discussed earlier, Jack Russell Terriers go into heat 2 times a year. Female dogs, unlike humans, go through estrus all through their lives, although the intervals between the cycles will become longer.

How to Care for Your Jack Russell When She’s in Heat

Keep Your Pet Clean

When your female Jack Russell is in heat, she will bleed and the bleeding may be very light or heavy. She may also mark areas and objects in your home with her urine. And, you may be especially worried that the bleeding, discharge and urine will completely ruin your couch, bed, carpet and all other furnishings that your pet sits on.

Fortunately, during the heat cycle, the female Jack Russell normally bleeds for around 7 to 10 days. This essentially means that for the rest of the heat cycle, there will be little or no bleeding or discharge.

Usually, your pet will keep herself clean by licking; however, sometimes, you may have to help by spot cleaning your pet, washing and wiping her with wipes or giving her a bath to prevent breeding and build-up of bacteria.

To prevent any mess in your home and avoid stains on your furniture or carpet during the time that your Jack Russell is in heat and is bleeding, it may be a good idea to make your dog wear period diapers. But make sure to change the diaper frequently.

Also Read: Complete Guide to Jack Russell Terrier Colors and Markings

Constantly Supervise Your Pet When Outdoors

When your pet is in heat, she may become very vocal and clingy and may indulge in annoying behaviors like trying to hump you, her toys, other pets and objects around your home.

Avoid leaving her outdoors in the yard or any other place unsupervised because a female in heat is sure to attract male dogs wanting to mate. Avoid letting your female Jack Russell in heat roam around freely in the park and always put her on the leash when taking her for a walk.

Groom Your Pet

Grooming your Jack Russell when she’s in heat can make life a lot easier for you and also keep your pet clean, neat and tidy. Trim the fur around your pet’s genitals because the blood and discharge during the heat cycle can get into the fur causing it to become matted and messy.

Trimming the fur around the vulva can help to make your pet more comfortable while making it a lot easier for you to keep the area clean.

Give Your Pet Love and Attention

Being in heat can be a very confusing and difficult time for your female Jack Russell. During this time, your pet may become very clingy and may need more attention, cuddles and snuggles.

Providing her with a chew toy or a blanket can offer your pet some security. If your Jack Russell bleeds on your furniture or carpet and makes a mess, avoid scolding her. Instead, reassure her and clean up the mess, which she didn’t make intentionally.

Make sure that your pet eats a healthy diet and give her plenty of water to drink. When your dog is in heat, she may have the urge to pee frequently and so give her a greater number of potty breaks.

Also Read: How Much Do Jack Russells Cost?

Wrapping Up

If you are a female Jack Russell owner and if your pet has not been spayed, then it is important to know about her heat cycles, prepare for it and know what to do when your Jack Russell is in heat.

If you want to completely stop the heat cycles from occurring, then it is best to get your pet spayed. This can help to prevent unwanted pregnancies, unpleasant behaviors, mammary cancer and other health conditions.

And, if you don’t want to get your Jack Russell fixed, then make sure to keep your pet away from other dogs when she is in heat and take steps to ensure that your pet is comfortable and happy during this time.