Apparently, Ed Norton has some sort of allergy to dogs in this episode, yet in "The Sleepwalker" it is not mentioned or alluded to, even when Ed is sleepwalking with Lulu the dog.
It is extremely unlikely that Alice, who is always lecturing her husband Ralph about things such as equality, fairness and how there is no boss in their apartment, would actually make such a major family decision to adopt a dog without consulting him.