You need to be in immediant contact with a vet! Pups that young can't live on regular milk, if you could express the mothers milk, contain it, you need to get a syringe, larger, without a needle, to suck it up in. Your vet will tell you how much and how often too feed, if you work outside the house you will need a team, to feed the pup every two hours or so, they can't survive eating every 8 hours for example, this means in the middle of the night too. Try as often as possible to re-introduce the pup to the dogs nipple, unless she barks or growls in protest. The vet has a special formula for pups, if you could at least get some mothers milk, that would be optimal, in that mothers milk lies an immunity to every cold almost every sickness she has ever had. It is also super high in nutrition, nothing else compares. Obviously this is going to be a lot of hard work, you may want to consider calling your local chapter of animal rights organization, you could also call no kill shelters and see if they are willing to take the pup, animal control may also be able to refer you to an agency, or foster network.
If you do want to keep the pup, you become its mother, they can't poo or pee on their on yet, you have to take a warm damp cloth and rub it on therir anus, to stimulate, the release reaction, you have to do the same on the place the urine comes out, at least after they eat. The vet can tell you how often. Being its adopted mom, it needs to know your close to it even when your not. Their sense of smell is their overwhelming sense. You will need to get an old tee shirt for example and wear it for awhile, at least a few hours, no perfume, lite deodarent. He needs to smell your natural smell. As a newborn he needs to be comforted a lot, he needs to know your there when he cries, not all the time, you don't want him so attached you can't even set him down. His bedding needs to be cozy, safe from things that might suffocate him, he shouldn't need blankets, dogs have a natural thermostat, he may however shiver, that's when you pick him up and warm him with body heat. Do however put the old you smelling shirt in the bed with him. I wouldn't suggest sleeping with the pup, it is easy to roll over in the middle of the night. There is a greater mortallity rate for abondoned animals, you may want to keep in mind, the dog may pass from this world despite your best efforts. I pray that you make the right choice for you and the pup. Best of wishes, I comind you for tring. Good luck
If you do want to keep the pup, you become its mother, they can't poo or pee on their on yet, you have to take a warm damp cloth and rub it on therir anus, to stimulate, the release reaction, you have to do the same on the place the urine comes out, at least after they eat. The vet can tell you how often. Being its adopted mom, it needs to know your close to it even when your not. Their sense of smell is their overwhelming sense. You will need to get an old tee shirt for example and wear it for awhile, at least a few hours, no perfume, lite deodarent. He needs to smell your natural smell. As a newborn he needs to be comforted a lot, he needs to know your there when he cries, not all the time, you don't want him so attached you can't even set him down. His bedding needs to be cozy, safe from things that might suffocate him, he shouldn't need blankets, dogs have a natural thermostat, he may however shiver, that's when you pick him up and warm him with body heat. Do however put the old you smelling shirt in the bed with him. I wouldn't suggest sleeping with the pup, it is easy to roll over in the middle of the night. There is a greater mortallity rate for abondoned animals, you may want to keep in mind, the dog may pass from this world despite your best efforts. I pray that you make the right choice for you and the pup. Best of wishes, I comind you for tring. Good luck