vitamin deficiency

What’s the general consensus for providing things like vitamins or probiotics in water for our feathered angels? I’ve read that it’s not effective because it gets diluted and broken down.

Hi guys! Looking for some insight about what the avian vet told us today. Our almost 10 yo Pionus has had chronic sneezing/respiratory issues since we adopted her 2.5 years ago. The issues come and go, and never seemed to get worse; we didn't have the money to afford full testing, and when we...