Sensitive Little Pittie

This weekend Russ had a bit of a medical scare.  A few weeks ago at the park Rusty was acting as if he got stung by a bee on his chest/stomach.  We brought him home, took out what we thought was a stinger (not sure what it was now), cleaned it and gave him some benadryl.  He was fine but we kept an eye on the "sting".  What went from a small red bump soon turned into a large red tumor like growth.  So, this weekend we went for a mini anniversary vacation to the beach, and left Rusty with my mom (a vet tech at our animal hospital).  We scheduled an exam for him and it turns out that the growth was called a histiocytoma.  The doctor decided to remove it because Russ was starting to scratch at it with his back paws. We weren't really too worried.  He had been put under anesthesia before for his "snip snip" surgery and he was fine.  We should have known though that all would not go as planned.  He has had funny reactions to certain meds in the past.  Anyway, he ended up having a reaction to the anesthesia (ketamine) and had seizures for over 2 hours as a result.  They were able to remove the tumor and it did end up being benign as expected.  Thank goodness my mom was with him....I can't imagine how scared my little boy was having seizures for so long.  Now, because of the physical and emotional stress endured by his body over the last few days he is having a hard time keeping food down and has some blood in the stool (the vet assures me it's probably from stress and we will be keeping an eye on it for the next day or so). 

For such a strong dog, he really is sensitive to medication and very fragile when it comes to the few medical issues we have experienced with him over the past year.  The only difference this time is that he was at a very healthy 80lb weight for his size, so the fact that he has dropped a few lbs is not as scary as a few months ago when he only weighed 60lbs and dropped lbs really fast because of the steroids he had to take for a skin infection. 

My poor little boy...has no energy and all he can do is sleep.  We will be taking it easy for the next few days and hope for the best.  Does anyone have similar experiences or any advice?