Dog behaving oddly?

Hi everyone,

I hope you are well and your pets. I am posting here because I do not know what else to do. My dog is 11 and since Friday he has been behaving oddly. He has always been full of energy, greeting me at the door, tail wagging, hanging with his furry dog brother, snatching each others treats, barking when he is excited. However on Friday, he did not eat or drink water. He was just laying down, seemed to walk with a slight limp on his left leg when he did walk. When I grab his legs he did not cry. However he also did not want to be touched. The whole day, he was just laying down. We took him to an emergency vet and his blood work was fine. His cholesterol according to the doctor was a little high. They even did an abdomen scan, but no luck. They could not tell us what is wrong. He was sent home with some pain meds. They just gave him an IV for hydration at the vet. Now 3 days later and he is still acting the same way. I am so worried for him. I don't know what else to do. He is not himself and seems like he is not feeling well. Any recommendations. I am thinking of going to another vet to see if they can find out. I am located in New York, Brooklyn. If anyone has any recommendations for a good vet or any information at all, it would be greatly appreciated.