yes rearguard stops the maggots developing, rather than repelling flies, but it would cost me £70 for all my bunnies (and I guess piggies can get it too!)
healthy, active, slim rabbits aren't really at risk from flystrike - If Bilbo had a growth then maybe he had lost the feeling from that part of his rear end - I would guess a fit rabbit would shake off a fly as soon as it landed
The thing I found with these bluebottle flies (it's just these big ones that do the damage - the houseflies are dung feeders) is they overwinter in nooks and crannies in your house and in sheds etc.
I have found 2 of them inside the overhang on Benny's hutch this winter - they wake up a bit on a sunny winter day, then try and find somewhere sheltered - I had to squish them with my bare hands which was vile but I wasn't going to go and find some fly spray at night - I only saw them when I shone the torch around his hutch! :shock:
I have also found them in the curtain heading pleats in winter - they wake up in spring when it's warmer.
I have a net curtain over my shed window, and I will staple nets all around Benny's hutch and run in Spring too - not much of a view for him but it will keep mozzies off too (main carrier of myxi)
In summer when I shut the girls up I check all round the shed for flies, and spray the net curtain with flyspray - then go outside and spray round the door and window (which needs to be open for ventilation) with Deet fly repellant, from Boots travel products. I spray it in the morning too, as it only lasts 7 hours.
At the end of last summer I sprayed the Deet along the roof of the hutch when I shut Benny up too, morning and night.
Then there are citronella candles, smoke coils, I had some Vapona (I think) window stickers from Sainsburys, that had slow release fly killer - they were great! fly papers are yucky to handle and dispose of, but they work - When my bunnies are on the patio I spray Deet around the drains and on the sunny gateposts etc that bluebottles like to sunbathe on - and I used a citronella type fly smellie thing - All guns blazing here! :evil: