I've already mentioned this one, but some more reading and the addition of possible seizures to the list of problems makes me bring it up again. May not be this, probably not this, but it might be worth some thought if your vet can't find anything else, especially as it can be treated if detected early.
There is a condition in boxers (and in Beagles, Bernese mountain dogs, and German short-haired pointers) called meningeal vasculitis. In poking around I'm also seeing it categorized as steroid-responsive meningitis-vasculitis, which doesn't appear to have a breed predilection and probably lumps a number of different conditions with similar pathologies.
From the text again:
Quote:The classical meningeal signs are fever, cervical {neck} rigidity, and spinal pain. Progression to neurologic signs, including ... seizures, may rarely occur. ... Some affected dogs have concurrent immune-mediated polyarthritis.
...
Multiple littermates are commonly affected, and many affected dogs have been closely related, suggesting a hereditary basis for the disorder.
From
http://merckvetmanual.com/mvm/index.jsp?cfile=htm/bc/60208.htm, who don't mention Bernies and add Akitas, and call it by another name (though I'm pretty sure they're describing the same thing as my text)
Quote:A steroid-responsive meningitis has been seen in adolescent or young adult Beagles, Boxers, German Shorthaired Pointers, and Akitas, but is very rare in other pure and mixed breeds. The clinical signs in Beagles, Boxers, and German Shorthaired Pointers consist of cyclic bouts of fever, severe neck pain and rigidity, reluctance to move, and depression. Each attack lasts 5-10 days, with intervening periods of complete or partial normalcy lasting ≥1 wk. {emphasis added}
Can you get any information on Zoe's littermates? On dogs in her lineage?
A short report at the link below suggests that Boxers may do pretty well with this disease, but early detection is big.
http://www.jaaha.org/cgi/content/abstract/42/4/277
