Please no trolling or junk posts in this thread. I'm posting this here because I've run out of ideas, and would like to help my very old dog.

I have a 15 1/2 year old male pug. Like many people on this earth, he's had a bad 2020.

The average male pug lives to 12 3/4. My pug is about twice the size of a normal pug (not fat, just large), so I thought the chances of him outliving the average was fairly low. However, he was doing surprisingly well until the end of 2019. Just about never got sick. Never had a major health issue. Surprisingly nice coat, which made him look far younger than he actually was.

At the beginning of 2020, something abruptly changed. He started losing his fur, had a mangy look, and had some raised black spots on his skin. He also started to smell very bad. I found that if I give him a bath, he stops smelling bad for about 5 days, but within a week he smells terrible again. Also, when I wash him, tiny black dots fall off of him.

My first idea was mange, but he has none of the mange symptoms except the fur falling out.

My second idea was fleas (thus explaining the tiny dots, which could be eggs). However, the problem began in the winter, and fleas aren't active in the winter where I live, because temperatures at night are too cold, often near freezing. He also isn't itchy, from what I can tell.

The vet called it a "skin infection", but didn't seem very sure. A second vet said the same. However, the pills prescribed and medicated shampoo did not make a dent in the problem.

I posted this problem to a Facebook group, and another poster had the EXACT same issue with another breed of dog (also old), and had the same frustration with the baffled vets and the ineffective treatments.

Any ideas of what this could be? I'm not expecting a 15.5 year old dog to be in perfect health, and I'm willing to accept that weird shit will start happening as they get way past their life expectancy. Like really old humans, there's only so much you can do.

If anyone has experienced this, or you think you know what it is, please let me know.