I have never seen this. 4 month old. Bottom front teeth show two more what looks like small teeth behind them. In other words they all look like baby teeth ? What in the world is this ?
Looking at puppy teeth between 4 and 6 months can be a very scary thing to do. You will see teeth in various stages of coming in and going out - some will be grey in color and sticking out sideways ready to come out and some will be replaced by huge permanent teeth - try not to assess pup's teeth by what you see at this age!!