Limping and gapeworm

[Bridgertrot]

I noticed today that one of my ducks seems to have a slight limp. I'm not sure what is causing it exactly but once the boyfriend gets off of work we can check his feet. It'd be a little hard to check him with one person. I'm a little worried that he might have a little sore on his foot. The bottom of my coop is concrete and I've always been a little concerned that might happen. If it's a sore, what's the best thing to help heal it? Also, I might need a new plan for flooring. I have a wire dog crate that I put shavings into the bottom of that they like to sleep in. I feel like I may have to put shavings in the entire coop to make the ground easier to walk on. Only problem is that their coop is about the size of a horse stall (for just two ducks) so I feel like I'd be spending a lot on shavings...though I may have to end up doing that. Plus the concrete is easier to clean.

The other thing is about gapeworm. The same duck has had a slight cough for a while. It used to be worse before so I consulted a vet about it. They couldn't really give me any answers other than they could run a bunch of tests which were pretty pricy. So I just kept a close eye on him. It seemed like it went away for a while and now it came back. I did some research and gapeworm came up as a possibility. Is there a website or someone who knows about locations where gapeworm is a problem? I talked to the guy who owns the local feed store (and a bunch of chickens) and he's never heard of it. He did mention that some things like this are more common in wetter climates vs dry ones, which is a good point. So is gapeworm prevalent in Colorado?

Thanks for the help.