The deep bowl on my fountain has a crack in one side which has not presented a problem over the past two years. However, after standing empty for a while, it was filled yesterday and the pump turned on. This morning, the bowl was bone-dry!! It could be coyotes ( we do have them) or neigborhood thirsty dogs, but I tend to believe the crack must be the problem. What can I seal it with without causing harm to wildlife and/or neighbors' animals?