Hello, I've had my female Cockatiel for about 6 months now. I bought a new one about a week ago. I bought a male Cockatiel who was younger than her. The male is lazy and he just sleeps most of the time. I've noticed he has diarrhea and thought it was normal because he was scared etc.(I thought that because when I bought the previous one the I saw the same thing but after a while it went away) and his voice is .... deep? I odn't know how to say it but its like different from other cockatiels I've heard. It's been 2 days and now I've noticed diarrhea and laziness around my female Cockatiel as well. I took the male to the vet thinking he was the problem and told him everything. He gave me some kind of medicine to put in the water for the bird and to check in 4-5 days later. Its been a day... I've googled some things and I've found out about Newcastle disease and this made me a bit afraid are these signs for Newcastle? or is it just normal for birds to be lazy when its cold? Honestly I am worried. Oh and I'd like to note out that my female cockatiel tends to eat her own feces ever since I bought her. The vets told me it was a behavioral problem or a Vitamin need. So I thought she might've mistakenly ate the other tiels feces and it made her sick as well? Any help would be appreciated on this topic.