hi kay, i use a canon eos 450d slr, most of my action shots of the dogs, birds in flight, anything with alot of fast movment realy are taken with the 70-300 lens as its a fast lens with great optics and always gives me nice clean detailed shots.
now i have to point out that although i have sold alot of prints and done quite a few portraits of mates dogs for them i donot consider myself a pro in any sense, its just a hobby i have a knack for.
i think more than anything practice is the key, i usualy take in excess of 300 pics when i,m out with the dogs or out mooching about and have l