What Age Can a Boston Terrier Get Pregnant?

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Planning a pregnancy even in Boston Terriers is very important. I should be well-prepared in terms of their needs before and during pregnancy, and after they gave birth. My Boston Terrier mom-to-be should also be well-prepared.

So you might be wondering, at what age can a Boston terrier get pregnant? Let’s dig into this article to know more about Boston Terrier’s best age to get pregnant.

At What Age Can a Boston Terrier Get Pregnant?

A Boston Terrier can get pregnant as early as 6 months old. Female Boston Terriers can reach their sexual maturity between 6 to 12 months of age.

Graphic image of a black and white Boston Terrier explaining that Boston Terriers can get pregnant as early as 6 months old

However; it’s best to wait for the dog to reach physical and emotional maturity to ensure that it’s ready for pregnancy, which happens when they’re about 24 months old.

There are many things to consider and learn before allowing Boston Terriers to get pregnant. Let’s begin with the heat cycle.

Boston Terriers’ Heat Cycle

The average heat cycle lasts up to 21 days. They typically have two heat cycles per year. Each dog differs in the length of heat, hormonal changes, and the amount of discharge. During the heat cycle, your female Boston will start looking for a mate. 

There are a few signs to look out for a Boston that is in heat. They may not go through each one of these, and that’s normal. You just have to learn how to recognize if your Boston Terrier is in its heat cycle:

Boston Terrier sitting on the pavement
  • Urinating more often
  • Becoming more affectionate
  • Becoming lazier or tired
  • Raising her leg when she sees a male dog or when urinating
  • Paying more attention to male dogs
  • Escaping or running away

Reproductive Cycle of Boston Terriers

Proestrus The beginning of the heat lasts for 7 to 10 days and the female starts attracting males although she will refuse to be mounted. the vulva starts swelling and blood will flow.
Estrus Estrus is the mating period that lasts for 5 to 10 days. Blood flow decreases until it stops. Females attract and are ready to accept males.
Diestrus The period after the heat. It lasts between 10 to 140 days. The female is either pregnant or in a resting phase.
Anestrus The resting period between diestrus and the next heat cycle.

Signs of Pregnancy in Boston Terriers

If you’re suspecting that your Boston is pregnant but not yet sure about it, here are some early signs of pregnancy that you should take note of:

  • Loss of Appetite: The early sign of pregnancy is a decrease in appetite. Some female Boston Terriers may just prefer to lie around the house or sleep.
  • Lethargy: Pregnancy takes a lot of energy. If your Boston Terrier seems to be in no mood for play, this could be the reason.
  • Bigger and Firmer Nipples: Any pregnant dog will show this sign of growth in its nipples. This is a preparation for milk production and breastfeeding. It is the most obvious sign of pregnancy, aside from a swelling belly.

Some Bostons may experience all of these signs, others may not. Some of them may experience more signs than these. Whatever the case is, you must consult your vet and have your Boston Terrier checked for pregnancy.

This is the first step to ensure that your soon-to-be mom Boston Terrier and her puppies are safe and healthy.

How Many Puppies Will Boston Terriers Give Birth To?

The average number of puppies of a Boston Terrier is 4 to 5. The number of puppies your Boston Terrier will give birth to depends on their body. Some can give birth to up to 7 puppies but that is very rare.

Boston Terrier puppy

Factors Affecting Boston Terrier Litter Size

  • Inbreeding: Inbreeding is a method used by a breeder to ensure that the desired traits will be passed on to the next litter. The more inbred the puppies are, the fewer the number will be.
  • Breed: The breed of the dog is a huge factor in litter size. Generally, the smaller the breed is, the smaller the litter size. The same rule applies to larger breeds.

For instance, smaller dogs such as our Boston Terriers can only have 2 to 4 puppies in a litter. Retrievers, on the other hand, usually have an average of four to eight puppies.

  • Age: Age is also a major factor in the puppy litter size. Do not breed your dog too early or too late. According to AKC, female dogs should be bred after the first heat. It is for the mother dog and the future puppies’ welfare. Dogs between ages 2 to 5 usually make the largest litter. It is normal for them to have fewer puppies for the first time.
  • Health and Diet: Both parents should be in excellent health to produce a larger pool of puppies. The food they eat and their diet plays a vital role here. An excellent and balanced diet even before pregnancy should be in check. If no supplementation is needed, the better. They should also have more calorie intake.

How To Take Care of Pregnant Boston Terriers

Pregnancy is a really risky period in the life of my Bostons. I should give them optimal care. Here are some things that I can do to take care of a pregnant Boston terrier.

Pregnant Boston Terrier lying on the grass
  • Avoid vaccination. Make sure all needed vaccines are updated before breeding.
  • A raw diet is not recommended for pregnant and lactating dogs.
  • Avoid strenuous exercises especially during the first two weeks of pregnancy and when giving birth is near.
  • A regular visit to the vet is recommended to ensure the overall health of the mom and the pups.

Related Questions

How Long Do Boston Terriers Get Pregnant?

The gestation period or pregnancy in Bostons normally ranges from 57 to 65 days. The average length of pregnancy is 63 days. Expect the delivery date to be from the 63rd to the 65th day of pregnancy.

Can Boston Terriers Give Birth Naturally?

Boston Terriers should NOT be allowed to give birth naturally as much as possible. The majority of pregnant female Boston terriers would suffer dystocia (several birth difficulties) if allowed to give birth naturally.

Currently, a whopping 92.3% of Boston terrier births are by cesarean. Some female Boston Terriers can handle natural birth but there are still risks.

At What Age Does a Boston Terrier Go Into Heat?

A Boston Terrier can go into heat at the age of 6 to 9 months. She generally reaches puberty age at that time and goes into her first heat cycle lasting for three weeks.

Dogs 101 - BOSTON TERRIER - Top Dog Facts About the BOSTON TERRIER


Female Boston Terriers experience their first heat cycle and can get pregnant as early as 6 months old. However, I should wait for them to be fully matured to avoid complications or health issues. The acceptable age for Boston Terriers to get pregnant is at least 2 years old. You may expect at least 4 to 5 puppies from her.