Ginger was neutered a little more than a month ago. We sometimes notice his penis come out when he's excited but as soon as he's calm it goes back in. Today it's been out all day. Any ideas? Do you think I should take him to a vet tomorrow if it happens again?
This happens to my little dogs (shih tzu mixes) all the time. They havent had problems I think it's normal

I wouldn't worry as long as it doesn't get stuck.

think this condition is called paraphimosis you may want to check it out in google
Thanks all for your replies. Luckily it hasn't happened again.