My dog has had a close call with death because of low blood platelets. They cannot find out why this happened. He got much better with prednizone treatments but when he is off the meds his platelets drop, so he may have to permanently be on steriods. The problem is , you don't know how sick they are until its almost too late.
Hi. I have recently had the same with my dog. She has been lethargic and acting differently for quite a while now, loss of appetite too so I took her for a check up. She had a high temp so is on antibiotics at the moment. The only info I have found drom the net are two diseases - one called EHRLICHIOSIS and the other THROMBOCYTOPENIA. If you Google them they both come up. Sorry I have nothing more. Good luck.
I have had similar with my dog recently. Two things I have found on the net are ehrlichiosis or thrombocytopenia. Ask your vet for more info. Hope your dog gets well!