Dog & Cat Pregnancy Milestones: Gestation Calendar
🩺 BREEDING SCIENCE

PET PREGNANCY
GESTATION
CALENDAR

Critical Ultrasound, Radiograph & Whelping Dates

63-day feline and canine gestation timeline based on clinical obstetrics.
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STAGE 01 • ULTRASOUND

VIABLE FETAL
HEARTBEATS

DAY 25 EARLIEST ACCURATE
ULTRASOUND

Ultrasonography at 25-28 days confirms viable cardiac flutters and gestational sacs.

💡 ACTION: Do not attempt palpation at home to prevent embryonic resorption.
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STAGE 02 • RADIOGRAPHY

ACCURATE HEAD
& SPINE COUNT

DAY 55 BONE CALCIFICATION
DETECTION

Fetal skeletons calcify after day 45-50. A day 55 radiograph gives an exact puppy/kitten count.

💡 ACTION: Knowing puppy numbers in advance prevents retained fetus emergencies.
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STAGE 03 • TEMP DROP

PRE-WHELPING
TEMPERATURE DROP

98-99°F NORMAL 101.5°F
DROPS SHARPLY

Progesterone plummet triggers a rectal temp drop below 99°F roughly 12-24 hours before stage 2 labor.

💡 ACTION: Take rectal temperature twice daily starting at day 58.
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STAGE 04 • NUTRITION

ENERGY-DENSE
PUPPY FOOD

+35% CALORIE INTAKE
THIRD TRIMESTER

Transition the dam to high-protein puppy food during the final 3 weeks to support rapid fetal growth.

💡 ACTION: Feed multiple smaller meals as expanding uterus compresses stomach.
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WHELPING READY

SAFE EMERGENCY
ACTION PLAN

2 HOURS MAX BETWEEN
DELIVERIES

Active hard straining without a puppy for >30 minutes or >2 hours between deliveries requires urgent vet intervention.

💡 ACTION: Keep 24-hour emergency veterinary contacts taped to the whelping box.