possibly replacing axle

We had a blowout this last weekend. We were not on the road 20 min. prior. It was a freshly paved road and we were driving about 55mph. We had no water on board, just clothes and what was left of our food from the trip (only 3 days and 2 people) so we were traveling light. It was the passenger side tire. When we removed the tire, we saw a pattern of wear around the outside in fist size sections that were worn smooth but the tread going down the center was good. Upon inspecting the remaining tire, we saw the same type of wear. We have only owned this used trailer for a couple of months and the tires were supposed to be relatively new. I did not notice any unusual wear when we purchased it . We have towed it under 1000 miles total.
In trying to replace the tires, it has been suggested that this could be an axle issue.
Has anyone experienced anything like this?
Cheri