They do not know what caused the infection...but when he was just 4 weeks to about 7 weeks he was around lots of other birds. But I dont think that is the problem because now he is at home and not exposed to any other birds and his cage is very well kept, he gets outside time when I come home. I have spent $80 at the first vet who did not know really what was wrong and gave him medication that did not do anything.
The avian specialist advised me to put him back on his antibiotics and possibly do a blood test....