My dog won’t eat but a few bites of food and a few sips of water for the past 4 days i don’t know what is

I don’t know what is wrong with him. At the end of last week i noticed some blood in his urine but that has seemed to cleared up some but not all the way. He will eat only a few small bites of food a day, not even a thimble full and he will only drink a little bit. My husband and i have been putting pedialyte in a medicine dropper and force feeding it to him to try to get him back hydrated. When we bought him they claimed he was only about 10 months old but we were his third owner???? I think he is dying of old age but what are the symptoms of a dog dying of old age because according to from how old he was supposed to be when we bought him he is suppost to be only 3 1/2 yrs old! But he really seems so much older since his teeth have changed and gotten really bad in the past year! Please someone help! I have told my husband that he needs to go to the vet tomorrow regardless of money but i need advice from other dog owners about the whole situation, thanks i appreciate it!
The papers we got when we bought him didn’t even seem like they belonged to him and was from an off name kennel club. can’t remember the name but not one i have ever heard of!
Thank you for all of your input, he is doing much better now and was diagnosed with a bad kidney infection and is on antibiotics and is slowly regaining his strength! Thanks!