I personally think it is worth you pushing for longer period on penG. The injectable antibiotics are better for treating these things, and oral along side that is not a bad idea.
It’s been a while since I went through this, but my rabbit that had lower jaw abscess on penicillin for about 6 weeks i think. More recently, I had another rabbit with facial abscess abs he had short acting penicillin every day for week then spaced out to every 2-3 days. The vet I saw always goes in fast with heavier duty antibiotics right away because infection moves fast also.
I’ll have to look over the history more closely as to how frequent the penicillin was post surgery and get back to you.
But to me, one shot of penicillin then oral baytril only isn’t enough to combat jaw infections.
Had the vet discussed leaving and antibiotic beads in place or anything like that? With the facial abscess bun, the vet left gel sponges in place that had an antibiotic on them.
What kind of aftercare did you need to do after the abscesses site was debrided?