We rehomed Elmo a month back, he seemed alright the first 2 weeks since we adopted, slowly he stopped eating and had a day of diarrhea and vomitting, took him to vet and antibiotics+probiotics were prescribed, even after 10 days he would not eat, so a blood work was done indicating severe Anemia and he does look pale, super tired, no interest in food or anything, his RBC count = 1.17 x10^12/L, HCT = 8.1%, HGB = 2.7G/Dl. They did a blood smear test after and nothing unusual was detected. As a temporary treatment, we started B12 weekly shots, force feeding a recovery diet with multivitamin supplement and hoping to test him in a month to see if the values have changed, but the doctor does not believe this is going to help much as she says this is non-regenerative anemia and a blood transfusion will help till the actual problem is detected. She wants us to do the bone marrow biopsy to detect any malfunctioning of RBC production, any auto immune diseases or even cancer and may be put him on steroids if needed. We are first time owners and its only been a month since we brought him home and this is too much for us to take in. Also so far we've spent generously for all the basic tests, doctor visits and vitamins, now the cost of these advanced tests she suggests is going to cost way too much, and considering he is already weak, this may be too much to handle too as he is still healing emotionally from thoughts of his previous owners and the physical stress of injections, force feeding etc. He is not the same dog who was 2 weeks back, just sleeps all day and won't have the energy to even go drink water (its only 3 days we started the force feeding food n vitamins, now force feeding water too), I don't know how in just 2 weeks time he can suddenly become this anemic and I want to know if his condition is as serious as the doctor says or its just the right food n vitamins that may help him pick up? Please suggest.