It could be kidney failure, it could be advanced diabetes, it could simply be that your pet has eaten something that smells really bad… poop, for instance.
And then there are those unexpected things. Pepper was in for a check-up in September. I talked with the owner about the accumulation of dental tartar, and how that's a bad thing. "Well, you just cleaned them recently." Time flies — it was over two years ago. "Well, I'll think about it." [This actually means "No; and after I leave here, I won't be thinking about it."]
Then, in the past couple of weeks, Pepper began to develop really bad breath. This forced his mom to make good on her promise to "…think about it." The more stinky he got, the more she thought about it. Finally she thought about it enough to decide to get his teeth cleaned.
And this is what I found. Yes, he had a lot of tartar on his teeth (I didn't make that up in September), but that wasn't where most of the stinkiness was coming from. This heavy thread was looped around an incisor tooth (#102 for you dental types) and he was trying to swallow the rest of it. It was accumulating hair, bacteria, and assorted ooey-gooey. It did stink (probably still does, if I were to fish it out of the trash). Since it was hooked on to his tooth, he couldn't really swallow it. Part of it was in his mouth, part was in his esophagus.
It's fairly long, and it had damaged the gums pretty badly around the tooth. The tooth was getting loose, so much so that I had to just extract it. I guess he might have eventually swallowed the whole mess when the tooth finally came out, but then he could have developed an intestinal obstruction from the string (the old "linear foreign body"). That's the tooth there on the left (look closely).
And don't go criticizing Pepper's owner. If he wasn't such an uncooperative little mutt, she would have been brushing his teeth, and noticing the string, and taking it out. Unfortunately, with this boy awake, it's hard to get a good look in his mouth. In fact, it's hard to get your finger back in one piece.
All's well that ends well… until our next episode.