Every summer, millions of pet owners carry their guilt on vacation alongside their sunscreen, reaching instinctively for their phones to bridge the distance between themselves and the animals they love. Veterinarians now caution that this impulse, however tender, may work against the very creatures it means to comfort — that a dog hearing its owner's voice without the fullness of their presence experiences not reassurance, but a kind of unanswerable question. The science of how dogs perceive the world suggests that sometimes the most loving thing we can do is resist the urge to reach out, and