My 8 yr old grandson was a healthy, chubby baby in the 50th percentile on the growth charts until he was about 8-9 months. He began to slide, and dropped off the scale completely by the time he was 6 yrs old. He now weighs 42 lbs., his younger 6 yr old sister weighs 45 lbs., and his average sized 4 yr old little brother now weighs almost the same. He has a very good appetite, yet isn t catching up. He also has dark rings under his eyes, and is always sick with something. His pediatrician tested for celiac disease twice now, but the tests come back negative. The term FTT has been floated around, however a cause or treatment has not been offered. Our daughter & Son-in-law feel lost with no idea where to go next. I am wondering if there could be a parasitic infection? They family has always had pet dogs. The one they had at the time my grandson was born developed serious gum and heart disease, and was later euthanized. Since then they have had another dog which struggles to maintain a healthy weight, and frequently will eat her own excrement. Should this be a possible focus of investigation?