It's hard to say for sure without seeing your puppy. But if it has a lot of itchy spots, hair loss, or crusty skin, it could be mange. You might want to take it to the vet for a proper diagnosis.
One way to tell is by looking for patches of hair loss, especially around the ears, face, and paws. If your cat is constantly scratching or has a crusty or scaly skin, it could be a sign of mange.
It could be due to exposure to infected animals or contaminated environments. Maybe your cat came into contact with another mange-infected cat during its outdoor adventures.
Your indoor cat can get mange. Mange mites can be brought in on your clothing or shoes, or a visiting pet could introduce them. Also, if your cat has a weakened immune system, it's more susceptible.