How Long Are Jack Russell Terrier Dogs Pregnant For?

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A Jack Russell terrier is popular for its merry devotion and pleasant character. Just like other dogs, your Jack Russell terrier being expectant can be one of the most exciting things, whether planned or unplanned. 

Now you expect a litter, and you do not know much about them. However, you may need more information on Jack Russells health when expectant than ever. So, how long is a Jack Russell terrier expectant for?

How Long Are Jack Russell Terrier Dogs Pregnant For?

Jack Russell terrier are expectant for an average of 58 – 63 days. However, time varies and 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 Jack Russel is expectant, you must ensure it gets the best care possible. You want to make the delivery process easy for the Jack Russell Terrier and ensure that the pups are in good health and the new mummy will be able to take care of them.

Methods to Determine if Your Jack Russell Is Pregnant

You may not be sure if your Jack Russell is expectant or not until you carry out a test to be certain. However, you may observe some sudden change on Jack Russell’s small body that may be a sign of pregnancy. These include:

  • Swollen belly to accommodate the puppies
  • Increased weight
  • Change in appetite 
  • Preparing a nest: Dogs prepare a quiet place around your house where the pet dog can give birth to its litter
  • Enlarged nipples
  • More affectionate
  • Reduced energy levels and an urge to sleep on regular basis

Home Pregnancy Test

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

Hormone Test

The vet conducts this test to look for Relaxin hormone in your dog’s blood. If it is done in the first half of the gestation period, it will indicate a negative. You should wait for at least 25 days before you do the first Relaxin test.

If your female Jack Russell 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 indicators that your pet dog may be expectant such as swollen nipples, you should consider other checking methods for pregnancy.

However, unlike ultrasound that shows the litter to expect, this method does not show how many puppies your pet dog is carrying.


It’s one of the ways to detect dog pregnancy and confirm your female Jack Russell terrier is expectant. Veterinarians recommend doing it between day 25 to day 35 of gestation as the expansion of the fetus begins exponentially.

Apart from doing the ultrasound to confirm dog pregnancy, there are also a number of things your vet can check on during ultrasounds.

  • Register the puppies heartbeats
  • Helps calculate the age of the fetus 
  • When the stork arrives or when the pups will be born
  • Indicates uterine distension
An image of Jack Russell terrier


This method is mainly used to tell how many puppies can be born. It is more effective when used in the latter days of the pregnancy when the skull and spine are visible and not during the second half of the gestation period. 

Weekly Jack Russell Pregnancy Calendar

Jack Russell Terriers have a weekly pregnancy calendar that runs from the date of mating to giving birth. The following calendar can help you understand your Jack Russell’s pregnancy stage and the right diet to give it.

  • Week 1: In the first week after mating, a couple of eggs move to the uterine horns and get fertilized. Although there are some hormonal changes in the first week, there are no noticeable physical changes.
  • Week 2: Since Jack Russell is not supposed to have a bodyweight increase of more than 10% until the sixth week, it’s advisable to start regulating the dog’s weight in the diet right from the second week. 
  • Week 3: The mother starts supplying nutrients to the developing puppies through the membrane. Although there might be no noticeable physical transformation, Jack Russell might be having cravings. Consider feeding it smaller amounts of healthy food more frequently.
  • Week 4: It’s advisable to visit the veterinarian in week 4 for ultrasound tests to confirm the pregnancy. They will also guide you on the right diets.
  • Week 5: The organs of the embryos start to develop into fetuses. The dog will start gaining weight significantly.
  • Week 6: The puppies develop more distinct organs, such as claws. Feed your dog foods high in protein, energy, and minerals to help in the development of the bone system of the puppy. 
  • Week 7: The organs continue to develop, including hair. The dog might start losing appetite due to increased discomfort.
  • Week 8: The puppies will have developed more distinct organs, and you can take your dog for X-ray tests. Again, you need to feed your pet a diet rich in minerals and proteins.
  • Week 9: There is a more significant change in hormones, and Jack Russell might start losing her appetite more. In week 9, keep in touch with the veterinarian for foods you should feed the dog. You should also keep checking the signals of labor.

Signs That the Jack Russell Terrier Is Heavily Pregnant and Almost Giving Birth

Even if you have seen the signs of pregnancy and even carried out tests to confirm, you might still want a sign that Jack Russell is approaching labor. The following signs indicate the time is due, and you should get your gear ready to help the dog deliver the pups.

  • Behavioral changes: Behaviors tend to change further when the dog is about to give birth due to rapid hormonal changes. In most cases, the dog will become anxious and restless as it seeks a safe place to give birth.
  • Loss of appetite and vomiting: The rapid hormonal changes during the last moments of pregnancy might cause nausea, making the dog unwilling to eat. Nausea can also cause the dog to eat and vomit almost immediately. It’s advisable to clean up the vomit and give the dog clean water.
  • Changes in body temperature: Usually, Jack Russells have a body temperature range of 101 to 102.5 degrees Fahrenheit. The temperature might drop to about 98 to 99 degrees Fahrenheit around 24 hours before labor due to the drop in progesterone.   
  • Panting: The dog’s belly will be sagging, and the dog will be exhausted and on high alert. The dog might start panting heavily, and you might even notice some abdominal contractions.
  • Vaginal discharge: In most cases, there will be a clear vaginal discharge up to 24 hours before the puppies are out. If the discharge is dark green, it means the placenta has detached, and the puppies are almost out. 

Related Questions

What Medication Can I Give My Expectant Jack Russell terrier?

You should not give your Jack Russell terrier any medication unless veterinarians have prescribed it. If the pet had been taking medication before, find out from your veterinarians if it is safe to continue with it.

How Long Are Jack Russell Terriers in Labor?

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


You have to be very careful about what your Jack Russell terrier will eat, the amount of exercise it gets. This is why it is crucial to involve your vet every step of the way and ensure that the Jack Russell Terrier is healthy, carries the puppies to term and delivers safely.