A vet said the 16-month-old dog should weigh around 50kg, but was currently just 23kg.
Champ could not stand on his own and needed blood transfusions, Animal Control said.
Rescue Dogs Rock NYC said: "Champ was transferred to our vet midday where he immediately started getting a blood transfusion. He was so pale with white gums that this was an obvious need. His bloodwork, as expected, is bad. His protein levels are too low as was his red blood cell count & of course he was very anaemic & LOADED with hookworms.
Champ could not stand on his own, was covered in maggots in his mouth and on his body and needed blood transfusions. Photo / Justice For Champ
"The hookworm burden was so high, the vet says his stomach is filled with tons of tiny bleeding ulcers. His blood has to be able to regenerate itself to combat this which it currently is not doing.
"We do not know if Champ can be saved or if we are in time, but we can promise you we will fight like hell for him to give this young majestic dog the life he deserves.
"If he makes it, he has a very long road back, so please keep the donations & prayers coming. He needs both!"
James has been charged with ill treatment of animals and will face court next month.
