However, it is important to note that you can't reliably tell a male puppy from a female puppy just by looking at them. While some differences may be present, like males typically having a slightly thicker neck and females a slightly smaller head, these are not reliable indicators.
The only way to know for sure is to:
* Consult a veterinarian. They will be able to physically examine the puppy and identify its sex.
* Wait for the puppy to mature. As they grow older, sexual differences may become more pronounced, especially in the case of dogs with a strong sexual dimorphism (like some breeds).
Remember, each puppy is an individual, and even within the same litter, there will be variation in appearance beyond gender.