“宿于狗舍” can be translated as "to stay/sleep in a dog kennel" or more naturally "to lodge in a doghouse" in English.
Here, “狗舍” is translated as “dog kennel” or “doghouse,” both of which are commonly used terms to refer to a shelter for dogs. “宿于” is translated as “to stay/sleep in” or “to lodge in,” depending on the context and the level of formality desired.