# Top 5 Most Interesting Puppy Facts

These facts were selected for their surprise factor, scientific fascination, and engagement potential.

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## 1. Puppies Can Be Born Green

In rare cases (less than 1 in 10,000), puppies can be born with green-tinted fur. This phenomenon is caused by a pigment called biliverdin that comes through the mother's placenta and mixes with the amniotic fluid. The green color gradually fades after a few weeks.

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## 2. Identical Twin Puppies Were Only First Documented in 2016

A South African veterinarian named Kurt de Cramer discovered two puppies sharing a single placenta while performing a C-section on an Irish Wolfhound. DNA testing later confirmed they were genetically identical - the first documented case of identical twin dogs ever recorded.

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## 3. Puppies Deliberately Use "Puppy Dog Eyes" to Manipulate Humans

Research has shown that dogs have evolved special facial muscles to raise their eyebrows, making their eyes appear larger and sadder. This expression is deliberate - dogs are more likely to make this face when they know humans are watching, and it significantly increases their adoption rates from shelters.

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## 4. Each Puppy Has a Unique Nose Print Like a Human Fingerprint

The rhinarium (the bare skin at the tip of a dog's nose) has a distinctive pattern of dimples, dots, ridges, and grooves that is unique to each individual dog. This pattern is fully formed by about two months of age and remains stable throughout the dog's life. The Canadian Kennel Club has accepted dog nose prints as proof of identity since 1938.

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## 5. Stone Age Humans Nursed Sick Puppies 14,000 Years Ago

A 14,000-year-old fossilized puppy jawbone shows that Stone Age humans nursed sick puppies. Archaeological evidence indicates that ancient humans cared for a puppy with canine distemper for several weeks, demonstrating the incredibly long history of the human-dog bond.
