My dog has a red, hard leg bump. What is it? Can I treat it at home?

Hi there! Thanks for using Petco Pet Education Center, formerly Petcoach! This is likely a focal area of dermatitis. This is likely to resolve on its own as long as you prevent any further self-trauma (preventing her from licking at it for example). You can get an e-collar from your local pet store or simply just keep a very close eye on her to prevent further self-trauma. In most cases of mild infections, if this is done at home, they can resolve as long as you keep that area clean. If no improvement of worsening is noted in the next 3-4 days, then have her examined by your veterinarian. However, there is a good chance she can do well at home. She is adorable! Have a good night!