Repacking wheel bearings on travel trailer

We just purchased our first tandem travel trailer last May (2013).
How often should I repack the wheel bearings? We probably have pulled the trailer about 800 miles so far. Thanks

If you purchased new there should be a manual with it that discusses this issue. If you have Dexter axles they recommend once a year except for their Never lube bearings. I think for those that tow annual low mileages probably every two years. As indicated previously, get an IR temp gauge and check every time you stop. If one temp is substantially hotter than the other three, you have a problem developing. It could be a brake dragging or a bearing getting hot.

I carry a spare bearing set, races, seal, grease, rags and the tools to change it.