I have a friend who has a 13 year old rabbit who was having seizures and the vet put her on phenobarbital and that has helped – they’ve had to up the dosage a few times once the seizures came back. Ask your vet about this.
As far as antibiotics on a 10 year old – it won’t really stress her system out – I have a 12 year old (and have had many senior rabbits on antibiotics with great success).
I have a very good relationship with my vet and my senior rabbit Bogie (12 years old) is having some issues as well and I rather opt to try something rather than nothing before making any decision. I do not want my rabbits to ever suffer and I always opt to euthanize sooner rather than later before my rabbits quality of life suffers greatly but it is only after trying my very best and having a very frank discussion with my vet about all possibilities and outcomes.
I guess the way I look at it is this way – is this condition treatable and is it the ONLY condition you are dealing with – if it’s multiple and you treat one but cannot treat all, would treating that one condition improve quality of life and how long do you continue to treat if that particular treatment is not successful.
That being said, I would have a heart to heart talk with the vet about possible treatments and outcomes – while she is 10 years old if there is something that can be treated with success then you should consider that.
Good luck in whatever you decide but really have a talk with the vet because they can be objective as well as subjective.