History
This animal is over 100 years old. One way they have changed over time is people are breeding them to be even smaller than what they were. Teacup Yorkies are an example of that. If this animal lived in the wild (it can't) it would keep down the population of rats and other rodents.
Life Cycle of a Dog
When they are born they are "blind" and "deaf". When they get to be about 4 weeks they can see and hear things clearly. When they are between 5-6 weeks old they start to seperate from the mom a little bit. The dogs are fully seperated from their mom when they are 6-12 weeks. When the dogs are 3-6 months their permanant teeth appear. During the 6-12 months they are constantly wanting to chew on things. They are pretty much grown up when they are about 3. The average life span of a dog is 12.8 years.