The 9 Weeks of Canine Gestation

Days 1-7: sperm can stay viable up to 7 days, so conception may lag mating. Days 8-28: embryos implant around day 16-18; heartbeats show on ultrasound by day 25. Days 29-63: organs form, skeletons calcify (X-ray count from day 45), and the dam's nutritional needs rise 25-50% in the final three weeks.

Nutrition and Warning Signs

Switch to puppy or all-life-stage food from week 5, in multiple smaller meals. Avoid calcium supplements unless directed — excess calcium impairs uterine contractions. Call the vet for green or black discharge before the first puppy, over 4 hours of active straining without a pup, or extreme lethargy.