Dog pregnancy signs: what you can see and when

Why looking is unreliable

The Merck Veterinary Manual describes false pregnancy as common in female dogs. It happens at the end of the heat cycle and brings weight gain, an enlarged abdomen, swollen mammary glands, milk production and behavior changes. Some dogs nest with toys or shoes and refuse to eat.

These are the signs people list as pregnancy signs. Because a non-pregnant dog can show all of them, none of them proves a pregnancy. How long it lasts varies: Merck says it usually ends on its own in one to three weeks, while VCA says the signs can appear for about two months after a heat.

What happens, and what a vet can find, by stage

Dates are counted from mating or ovulation, and the exact day of conception is often uncertain, so treat each figure as a range.

• Around day 18 to 21: the embryos implant and small swellings form along the uterus. Merck says a vet can feel them at about day 21 if the dog is cooperative. VCA puts the best window for palpation at three and a half to five weeks, and says the results vary.
• Day 22 to 27 onward: a blood test measures relaxin, a hormone made by the placenta. VCA says it can be positive from 22 to 27 days after breeding, while Merck’s owner page gives day 30 to 35, so ask your vet when to test. It is negative in false pregnancy, so it can tell the two apart.
• Day 25 to 35: ultrasound is most useful here, according to Merck, and it shows whether the puppies are alive. Before day 21 it can give a false negative.
• About week 6: VCA says her food should stay the same for the first two thirds of pregnancy, about six weeks after mating, then rise gradually.
• About day 42 to 45 and later: puppy skeletons show on an X-ray, and an X-ray after day 55 is the best way to count the litter.
• Final days: a drop in rectal temperature usually comes about 8 to 24 hours before delivery, according to Merck. Cornell describes nesting, panting and discomfort 6 to 12 hours before birth.

Which signs are unreliable

Treat all of these as possible, not proof: a bigger belly, weight gain, larger nipples or mammary glands, a changed appetite, being quiet or restless, and nesting. The same list describes false pregnancy.

Even a negative test needs care, because a blood test done too early can be falsely negative. Our dog pregnancy test guide goes through each test and when it works.

False pregnancy and other lookalikes

A false pregnancy usually ends on its own in one to three weeks, says Merck, so treatment is often not recommended. It also advises not to milk the glands, as that stimulates more milk. Talk to your vet if she is uncomfortable or the behavior is a problem.

A swollen belly after a heat can also be pyometra, an infection of the uterus. Merck says it tends to occur 4 to 6 weeks after estrus, mostly in dogs over 5, with lethargy, poor appetite, extra thirst and urination, vomiting, and sometimes a discharge of pus. It needs a vet quickly.

When to call the vet

Call the vet to confirm a suspected pregnancy and to plan food and medicine, since VCA says some common medications should be avoided in pregnancy. Do not give any without asking.

Call if there is a vaginal discharge you are worried about, if she seems ill, or if labor goes wrong. Merck lists signs of a difficult birth, called dystocia: no birth within 24 hours of a rectal temperature below 100°F, strong contractions for more than 1 to 2 hours with no puppy, a rest of more than 4 to 6 hours during labor, obvious pain or illness, or an abnormal discharge.

If a mating was unplanned, see the vet. Merck says pregnancy can be ended or prevented, and that about 60% of misbred dogs do not become pregnant, so it should be confirmed before treatment.