I'm sure you'll be fine - last time I had one was after walking through long grass, on the edge of a field of sheep, which was up to my waist...
It felt rude not buy the Olympus 40-150 f4-5.6R lens direct from the Olympus webshop - for £149.
The lens weighs 190g and is 83mm long. Yes it plastic but.... its 80-300mm tele zoom for £150! And seems to work not too badly at all.
Edinburgh castle oly 40-150-2 by mr.noisy, on Flickr
Arthurs Seat oly 40-150-1 by mr.noisy, on Flickr
Jacobaea vulgaris (ragwort, stinking willie)