I have a 9 week old Brahma who is wobbly and gulping (not panting). I noticed she was puffed up two days ago but it was a cold day so I thought she was trying to stay warm. Yesterday I noticed she was wobbling on her feet. If she bends to eat or drink she almost falls over when she comes upright. Sometimes her wings droop. She is making a gulping motion often but not panting. She is eating fine, crop is working fine. Pupils ate fine, clean vent, no lesions in mouth or throat. I am giving her a vitamin supplement in her water. Is this Marek's? what do I do? She is seperated and no flockmates are showing symptoms.