Increasing Furosemide Intolerance

So, the cough has gone from generally dry to wet sounding & longer in duration. But there is still nothing coming up. And he's swollen - husky as we like to call it so as to not give him a complex. 

Over the last couple weeks the furo seems to be working less & less. I'm still giving it to him anyway. He refuses all pills (and has for most of this year), so I've resorted to crushing and mixing with food. Works like a charm if it's fine enough. Anyone who walks into our kitchen likely wonders if I've become a Colombian Drug Lord. I swear, I'm not. I'd totally be driving a brand spanking new Mercedes if I was....