DCat developed stinky breath a while ago... can’t quite recall how long ago we started noticing it. She was treated for hyperthyroidism, is on 25mg vidalta daily which she takes well and has been on for probably a year. I thought the bad breath had improved, but she’s been a stinker lately and has just poddled in from outside, jumped on the back of my chair and breathed in my face. It could strip wallpaper 
Is hyperthyroidism and bad breath linked anecdotally? Google is not my friend on this. Clean, white teeth, normal looking gums.