Unlike traditional vacuums, a Dyson brand vacuum cleaner uses a bin that allows you to dispose of debris after each use if you want. If your Dyson has an unusual odour, it may be due to something in the clear bin or an issue with the filter. Fixing the problem is something you can do yourself without needing to call for a service repair.
Check inside the debris for the offending stinky item, and dispose of the debris as normal. Never let the debris get above the marked fill line or you could compromise the efficiency of the vacuum or damage the motor. Rinse out the bin periodically to remove any built-up gunk, but don't put the bin in the dishwasher. Don't place the bin back inside the vacuum unless it is completely try.
Dyson suggests cleaning the vacuum's filters every month to keep them clean and in working order. After cleaning, wait the suggested 24 hours dry time before vacuuming, or you could cause mould and mildew to form inside the filter.
Don't vacuum wet substances unless your Dyson is specifically intended for wet use. Vacuuming wet items on a wet surface could cause electric shock.