RoxyAutoimmuneAndAnemia

My name is Amanda  ive never asked for help like this but idk what else to do.. My dog Roxy will be 3 on October 5th. 2 weeks ago she started having seizures when she got really excited. So we took her to vet and they gave her meds.we found out that that her blood levels were critically low. The vet told us she needed a blood transfusion but do to not having the money we had to get pills and go home . The next day we went back to vet and her levels were improving wich is a blessing. The vet was thinking it could be cancer  She had a xray and  They didn't  find anything which is good .Her blood levels it's at 32 on thursday  the 24th.. the vet mentioned taking her to a neurologist which I haven't gone because I don't have the money her next appointment is Sept 8th unless she's sick and I would have to bring   her asap. We have spent over 2000$. Trying to figure out what is wrong.  have pictures and receipts of bills if anyone is wanting to see the