hi this is my first post. i have a three year old vield. he is showing signs off agresion with me. he has always been great when handling and always happy but the last two days he has be very agressive and very dark in color. he is eating ok and does drink when he can be arsed. i have had him for two years now and have never exspirenced this with him. has anyone got and idea of what could be causing this. sorry about the spelling.