Not only may some residents not welcome the dog, but some people have life-threatening allergies to certain foods and animals. Although I love animals, I cannot be around dogs for more than a few minutes. I am severely allergic to them. Within 15 minutes of breathing dog dander my eyes start to swell , and I start to sneeze uncontrollably (yes, one right after another non-stop). If I just pat someone's dog on the head, I must immediately go wash up or I will break out in a rash. I think dogs are adorable, but I cannot imagine having to live around one. And yes, there are allergy medications one can take, but they often have side effects and interact with many other medicines (causing drowsiness, a raise in blood pressure, etc.) This may not be possible for people on many medications in a nursing home to take them, nor may it be covered by their insurance/medicaid/etc. Ask the nursing home what the reason is for not allowing the dog. There may be a legitimate medical reason it cannot be there.