In retrospect; it probably would have been a good time to find another loving home for your dog when you found out your wife was allergic to him. It’s sad when that happens but it’s far better for the pup and of course your wife would not have to suffer from the allergy. Time was on your side to find just the right home for him as much as it might have hurt you. Dogs that are pets like yours are far too often treated like livestock. People just feed and water them thinking that ends their responsibility but in reality all that is is the very basics in that responsibility. Dogs (especially; cats not so much) require a lot of attention. Yes, they will adjust and accept that’s just the way their life is, but it’s so unfair to any dog to be left alone in a back yard day after day. They just have an existence; not really a life.
Hindsight is always 20/20 though...
Cheers and regards.
In retrospect, it would be better for you to learn of the situation before you give out unsolicited advice. My wife's allergy would flare only if she was in an enclosed space with a cat or dog that is not an issue with an outside dog. She can be outside with them and even pet or handle the animal without it affecting her provided she washed her hands. When we had the dog, we had a household of kids who played with the dog constantly.
Hindsight is always 20/20 though...
Not if you're still making the decision based on an incomplete set of facts.