The first boxer I feel in love with, Prill, belonged to a guy I was dating. At the age of 8 he started to have seizures. We took him to the veternarian college to be checked out and within a few days he went form bad to worse. They found a brain tumor thru an x-ray, and it was sizable. We had to put him down. They did a necropsy on him, and found a total of 8 tumors. I think my bf wanted comfirmation he was doing the right thing and that is why he agreed to to the necropsy. Even tho all of us were suffering from a broken heart, we knew Prill was not suffering which made our pain a bit less.
If there is a neurologist in your area, I would at the very least want a phone consult, if not an exam. My heart goes out to you and Harley.