It does sound a lot like the behavior ours show when there's a mouse in the house, Jen. Sometimes you can hear rodents gnawing in the walls at night if that's what it is. Normally I get confirmation when I hear hubby and the Pack (8 dogs, all woosses) running down the hall with a mouse in hot pursuit (yes, none of them like mice much!
) Live traps are pretty cheap--we always have some onhand and bait them with nuts, then release the little varmints out back. (Probably, they end up right back in the garage or maybe even the house, but it makes hubby and the dogs feel better if they see me take them away.
Regardless, though, I don't think it's something allergy- or illness-related--it's just something dogs do.