m thinking there may have been several things going on there, including the possibility of diabetes (seizures are not uncommon in seriously ill diabetic
dogs). Diabetes can also affect both the liver and more so the kidneys over a period of time and when maybe the symptoms haven't been obvious, therefore appropriate treatment isn't given early enough.
The reverse can also be the case ... that is, the kidneys may have been affected first, which then caused the glucose levels to rise.