Could a sore foot cause other problems?

by Jessica
(Ottawa,Ontario, Canada)

For the past three days my Green Cheeck conure has been babying his right foot. He doesnt grasp onto perches or even fingers with it and he always has it tucked into his body. He has been eating and drinking and bathing talking and carrying on with his normal activities.

He has also developed some diareah. It still forms a little but is more liguidy and splatters everywhere when it hits the ground more than usual. He is also going to the washroom alot more than usual as well. He is also losing alot of his little under feathers. What could this mean?

I clean his cage regularly and ive tried testing for mites but nothing has appaeared. I would like to know what is gonig on and if i should take him to the vet. I am a new bird owner and need some advice.