I would definitely take him to a different vet. I did have some complications with one pug, but he was about 5 yrs old when we rescued him, and it is a lot harder on an older dog. He is also paralyzed in the back legs, so he scooted on the "balls" and they became very inflamed. He finally burst a small hole in one testicle, and the dried blood could escape, and then he healed up quite quickly after that. the blood there was very dark, but if you are seeing bright red fresh blood, you have a problem that should be looked at sooner rather than later.
On some dogs they may need anti-inflammatory to reduce the swelling, which also encourages them to move around more, which helps the swelling also.