based on general knowledge , if the White House were to blame a "stressful environment" for the first dog's biting spree, it would likely be an attempt to explain the dog's behavior by attributing it to the stress of living in a new and high-pressure environment. Dogs, like any other animals, can be affected by changes in their surroundings and routines, and a move to a new home like the White House, with its constant stream of visitors, cameras, and attention, could potentially be overwhelming for a pet.
In such cases, blaming the environment might be an effort to alleviate any public concern about the dog's temperament or behavior and emphasize that the dog's actions are not due to any inherent aggression or malicious intent. Instead, it might suggest that the dog is simply struggling to adapt to its new surroundings and the intense demands of its role as a first pet.