Sorry to be crude...but yellow pus oozing from dog's penis

In the past couple of days I have noticed yellow stuff coming out of my dog's penis. Sorry, this is kind of gross, but I'm wondering if this could indicate a problem and if I should take him to the vet. He seems to be able to urinate with no difficulty or pain.

A little bit of ejaculate is normal at times, especially if the dog is not neutered. If you are sure it's pus, he most definitely needs to see a vet because pus = infection, which will need antibiotics.

Agree with Carina