[Vectis Hamstery]

I think Bella was probably my most expensive single hamster in terms of vet bills with approximately £240 (she had her surgery in 2010 and her other treatment in 2011 so it may have been more, but I can't quite remember):
£30 on consultation and antibiotics
£160 on an ultrasound, x-ray, spay and follow-up
£50 on 2x consultations, medication and injections for heart failure

My most expensive month was this May when I had 3 small furries need surgery within 2 weeks:
£180 for Zuli's spay
£70 for Nin's abscess operation
£70 for Andromeda's surgery (and euthanasia under anaesthetic)

Thankfully, relatively few of my hams ever need to see a vet.

I once had a hamster with resistant mites - she came to me with them from a rescue centre. She needed a course of several injections to sort them out, and they never returned. I did, however, also have a male mouse who had recurrent mites and had an underlying health issue to which he later succumbed.