How Long Are Jack Russell Terrier Dogs Pregnant For?

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Your JRT being pregnant can be one of the most exciting things, whether planned or unplanned. Now you expect puppies, and you do not know much about them. However, you may need more information on dog pregnancies than you do. So, how long are Jack Russell terrier dogs pregnant for?

How Long Are Jack Russell Terrier Dogs Pregnant For?

Jack Russell terriers are pregnant for an average of 58 – 63 days. However, the puppies may come a bit early or later as it is challenging to know when exactly delivery will happen as it is difficult to know when conception occurred even if you know when mating happened as eggs are fertile for up to 48 hours and sperms can stay alive for several days.

An image of pregnant Jack Russell terrier

While your dog is pregnant, you must ensure it gets the best care possible. Ensure you visit a vet, take it on regular walks and watch what it eats. You want to make the delivery process easy for it and ensure that the puppies are healthy and that it can be able to take care of them.

Methods to Determine if Your JRT Is Pregnant

You may not be sure if your dog is pregnant or not until you carry out a test to be certain. However, you may observe some signs that may indicate pregnancy. These include:

  • Swollen belly
  • Increased weight
  • Change in appetite
  • Preparing a nest
  • Increased nipple size
  • More affectionate
  • Reduced energy levels

Home Pregnancy Test

Because of the name, you may assume the test uses urine to find out whether the dog is pregnant or not. While some tests claim to use urine, the results may be false. During pregnancy, when the placenta is growing, a hormone called Relaxin is produced.

The results may not be accurate. At the same time, you may not have the capacity to perform a blood test at home to see if the hormone is present. In the end, you will have spent money on something that you cannot be able to use.

This is why you need to let your vet conduct the test to determine whether your furry friend is truly pregnant or not.

Hormone Test

The vet conducts this test to look for Relaxin hormone in your dog’s blood. If it is done too early, it will indicate a negative. You should wait for at least 25 days before you do the first Relaxin test. If it tests negative, wait for seven days before doing the test again. It may be that the placenta had not started production when the first test was carried out.

If your dog is small, it may produce small amounts of the hormone that may not be enough to test positive. In such cases, especially if you have done the test three times and there are signs that your dog may be pregnant, you should consider other checking methods for pregnancy.

It is crucial that you know that a positive test does not mean that the puppies will be alive by the time your bitch is giving birth. It is only an indication of pregnancy.


This is the most reliable way of detecting if your dog is pregnant. Vets recommend doing it between day 25 to day 35 of gestation. Apart from doing the ultrasound to confirm the pregnancy, there are also a number of things your vet can check on during ultrasounds.

Unlike the hormone test, where you will not be able to tell if the fetus is alive, this method allows you to do that. It:

  • Registers heartbeats
  • Helps calculate the age of the fetus
  • Indicates uterine distension
An image of Jack Russell terrier


This method is mainly used to tell how many puppies you can expect. It is more effective when used in the latter days of the pregnancy when the skull and spine are visible. However, it may not be helpful in some situations; for example, if a fetus is no longer alive, an X-ray will be unable to detect it.

Related Questions

Other questions you may have are answered below.

What Medication Can I Give My Pregnant JRT?

You should not give your pregnant JRT any medication unless a vet has prescribed it. If it had been taking medication before being pregnant, find out from your vet if it is safe to continue with it.

How Long Are Jack Russells in Labor?

Jack Russells are in labor for between 12 – 24 hours, depending on their strength and the number of puppies. Intervals between the puppies should be between 15- 30 minutes. If it takes longer than that or seems unable to continue, contact your vet immediately.


Pregnancy can be fascinating, and it presents another opportunity for you to learn more about your dog. You have to be very careful about what it eats, the amount of exercise it gets, and the supplements and medications you are giving it. This is why it is crucial to involve your vet every step of the way and ensure that it carries the puppies to term and delivers safely.