I purchased eggs from a breeder off e-bay that had good reviews. A neighbor took some of the eggs to hatch and only had one hatch. I only had too. Her chick was weak and she asked me to take it and keep it with my other two. It seemed to get stronger but it had a dark bulge on it's underside that wouldn't get better. I thought it looked like internal bleeding. After it was about 4 days old it started looking like it had a hurt foot. Then, after I had it for 5 days my two healthy chicks started getting a wheezing sound in their breathing and sneezing. I looked on line and found Marek's disease. The sick chick seems to fit the symptoms except for it's age. Could a one week old chick be that advanced with Marek's? I culled it right away, but I'm not sure what to do about the two hens. Should I assume it's marek's or could it be something else? Most of my mature flock has not been vaccinated (now I know to make sure that's done) so I could try one of the remedies on BYC, but will they still be carriers if they get better? I had tried giving the chicks antibiotics and haven't seen an improvement. These two chicks are especially sweet and attatched to my kids of course! Thank you for any help...I need to do something quickly for the two remaining chicks if I am going to help them.