Sticky Beak

[GouldianLady]

My Gouldians have started doing something I'm not sure about.

In the morning when I give them water, after they drink, many of them make a sound I can only describe as "sticky beak." It literally sounds like their beaks are sticky. I occasionally hear this during the day, but mostly first thing in the morning after that first big drink.

I'm aware of air sac mites and treat as preventative regularly with Scatt.

I also recently tried a round of Amoxitex in case it was just a low-lying respiratory issue. Some improvement after that, but then it came back.

Don't see any tail bobbing. Birds are active overall, eating, flying, singing.

I'd call an avian vet but we don't have any here.

I'm currently trying a round of Ronivet in case this is a protozoal infection. Some of their poops do look bright yellow or bright green (a symptom) and yesterday I saw one of the fledglings doing that thing they do when they regurgitate for their young - only she has no young she is feeding (another symptom is vomiting). Only she didn't vomit out of her mouth...but I could tell she was regurgitating - does that make sense?

So - any ideas?

Any thoughts or advice are greatly appreciated.