As the doggy neighbor you are not obligated to provide anything for the dog’s stay. If you want to get a toy or snack for the dog because they’re just too darn cute for words, feel very free to go ahead as long as they are compatible with the dog’s safety.
Otherwise, doggy owners are always responsible for supplying all of their dog’s needs for the duration of their stay with you (i.e. food, toys, blanket, bed, medication, etc.)