A Detailed Guide to Determining if a Hamster Is Pregnant
1. Key Physical Traits
Abdominal Changes
Pear-Shaped Silhouette: In the mid-to-late stages of pregnancy (around 7 days after conception), the abdomen droops noticeably. When viewed from the side, it takes on a pear shape—narrow at the top and wide at the bottom.
Firm to the Touch: Gently feel the abdomen (with caution) to detect small, hard lumps roughly the size of mung beans (these are the developing fetuses). By contrast, the abdomen of an overweight hamster is soft with no such lumps.
Prominent Nipples: About 10 days into pregnancy, the nipples on both sides of the abdomen turn pink and protrude, with sparse fur around them (male hamsters have indistinct nipples).
Weight Gain
A hamster may gain 20–30 grams within a week (use a kitchen scale for regular measurements). While overweight hamsters gain weight evenly across their body, pregnant hamsters gain weight primarily in the abdominal area.
2. Abnormal Behavioral Signs
Increased Aggression
Sudden behaviors like biting the cage, attacking cage mates, or nipping at their owner. If hamsters are housed together, separate them immediately once pregnancy is suspected.
Frenetic Nest-Building
Shredding paper towels or cotton, piling wood shavings into a nest over 10 cm tall, and even carrying soft materials from around the cage to the nest area.
Decreased Activity
Abandoning the exercise wheel, moving clumsily, and spending more time lying on their side or huddled in the corner of the cage.
3. Changes in Eating & Excretion
Extreme Increase in Appetite
Developing a preference for high-protein foods (e.g., mealworms, boiled chicken breast), eating 2–3 times more than usual, and hoarding large amounts of food.
Frequent Urination
Due to the uterus pressing on the bladder, urination frequency increases. Change the bedding daily to prevent urinary tract infections.
4. Important Notes
False Pregnancy
Unmated female hamsters may show pregnancy-like symptoms (e.g., nest-building, nipple protrusion) due to hormonal changes, but their abdomen will not continue to grow.
Emergency Care
Once pregnancy is confirmed, provide a quiet environment free from bright light or loud noises. Stop cleaning the nest 16–22 days after conception (around the time of delivery).
Postpartum Care
Do not touch the baby hamsters after birth. The mother may abandon or attack her pups if their scent is altered by human contact.
Summary
A hamster’s pregnancy can be comprehensively determined by observing traits like abdominal shape, nipple changes, aggressive behavior, and extreme appetite gain. If you are unsure, consult an exotic pet veterinarian for confirmation.