Hello, thanks for your question today! I am Dr. Drew, and I am a licensed veterinarian. I'll be happy to help you in any way I can.
IN a case where a senior-aged dog is Anemic, and has been losing weight,
one of the big concerns is internal bleeding, caused by a tumor on the spleen or liver,
typically this causes what's known as a Regenerative Anemia, where the bone marrow is trying to make new red blood cells.
If tests have shown that no new red cells are being made,
then that's a Non-regenerative anemia,
and that may indicate that cancer has invaded the bone marrow,
or it may indicate some other type of issue such as kidney disease.
Non-regenerative anemia can be difficult to diagnose and to treat, unfortunately.
Also, since Sara is already taking antibiotics and steroids, there may not be as many options in terms of looking for signs of infectious causes of the problem, such as some tick-borne illnesses, etc.
Depending on how long she's been on the steroids, if there's no improvement after 10-14 days, I'd consider stopping the steroids but continuing an antibiotic such as Doxycycline, to help address possible tick-borne infections.