Quick answer: The most reliable early dog pregnancy test is a relaxin blood test, which works from about 22 to 27 days after mating. An ultrasound works from about day 25, and an X-ray from about day 45. Human pregnancy tests do not work on dogs. Enter the mating date below to see when each test will work for her.
When should you test your dog for pregnancy?
Timing matters more than the type of test. Test too early and even a pregnant dog can read negative. Use the planner to turn her mating date into test dates.
Tip: use the first mating date. Every test below is counted from it.
Earliest blood test (relaxin)
Pick a date
Dates are counted from mating. If she was mated over several days, add the gap to each date.
If you are unsure of the mating date, book the test for later rather than sooner. A test on day 30 is more likely to be right than one on day 22.
What are the types of dog pregnancy test?
There are four ways to test a dog for pregnancy. Each answers a slightly different question:
| Test | Works from | What it needs | What it tells you | What it cannot tell you |
|---|---|---|---|---|
| Relaxin blood test | Days 22–27 | A small blood sample | Pregnant or not | How many puppies, or if they are alive |
| Ultrasound | Days 25–35 (best window) | A vet scan of the belly | Pregnancy, heartbeats, how far along she is | An exact puppy count |
| Palpation | Days 21–35 | A vet feeling the belly | Swellings in the uterus | Whether puppies are alive; often unclear in tense or heavy dogs |
| X-ray | Day 45 on; best after day 55 | One or two images | Puppy skeletons and the most accurate count | Early pregnancy |
For most owners, the best plan is a relaxin test or an ultrasound around day 28 to 30, then an X-ray in the last week before whelping.
How does the relaxin blood test work?
Relaxin is a hormone made by the placenta. A dog only has a placenta if embryos have implanted in her uterus, so relaxin in her blood is a direct sign of pregnancy.
The test picks up placentas from about 22 to 27 days after mating. Relaxin then stays high until the pregnancy ends. A few points help you read the result:
- A negative on days 22 to 27 is not final. Retest one week later. Two negatives a week apart usually mean she is not pregnant.
- Tiny litters can be missed. A small or toy breed carrying one or two puppies may not make enough relaxin for a positive.
- A positive confirms pregnancy, not healthy puppies. It cannot show whether the puppies are alive. A later ultrasound can.
- A positive followed by a negative can mean the pregnancy was lost. Call your vet.
Are at-home dog pregnancy test kits accurate?
Some home kits measure relaxin in a few drops of the dog’s blood. These work on the same idea as the vet test, with the same timing limits. Kits that claim to read a dog’s urine do not have the same published evidence behind them.
Before you buy a home kit, check that it:
- Tests for relaxin, not hCG.
- States the earliest day after mating it can be used, and that day is 22 or later.
- Explains how to retest after a negative result.
Treat a home result as a first answer. A vet ultrasound is still worth booking to check the puppies’ heartbeats and plan for whelping.
Can you use a human pregnancy test on a dog?
No. Human tests look for hCG, a hormone made in human pregnancy. Dogs never make hCG, so a human test reads negative whether or not she is carrying puppies. It cannot give a true positive.
Which test should you choose?
- You want a yes or no as early as possible: a relaxin blood test from about day 28. Retest a week later if it is negative.
- You want to know the puppies are healthy: an ultrasound between days 25 and 35 shows heartbeats.
- You want to know how many puppies to expect: an X-ray after day 55. This tells you when whelping is truly finished.
- She looks pregnant but tested negative: she may have a false pregnancy. A relaxin test stays negative in a false pregnancy because there is no placenta.
The signs you can watch for at home are covered in our guide on how to tell if a dog is pregnant.
What to do after a positive test
A positive test is your cue to plan ahead. Work out the due date with our dog pregnancy calculator, then follow her changes in dog pregnancy week by week. Ask your vet about diet, worming and when to book the X-ray.
Frequently asked questions
Can a dog pregnancy test be wrong?
Yes, mostly through testing too early. A relaxin test before about day 22 often reads negative in a pregnant dog. A single puppy in a small breed can also be missed.
Does my dog need to fast before the test?
Usually not for a blood test or ultrasound. Some vets ask for a short fast before an ultrasound to get a clearer picture. Ask when you book.
Can a blood test tell how many puppies she has?
No. It only shows whether she is pregnant. An X-ray after day 55 gives the best puppy count.
Is an X-ray safe for a pregnant dog?
Yes, when done late in pregnancy. By day 45 the puppies’ organs have formed, and vets consider an X-ray at that stage safe.
Does a pregnancy test hurt my dog?
No more than any routine blood draw. Ultrasound is painless, though some dogs need their belly fur clipped. Palpation should only be done gently by a vet.
Can a urine test show if my dog is pregnant?
Not reliably. The proven tests use blood, an ultrasound or an X-ray. If you try a urine kit, confirm the result with your vet.