I have been crossing a Dogo and Catahoula for 13 years and have a few out that are doing a great job.
http://www.txmasoncatahoulas.com/gallery/thumbnails.php?album=23Called Catdo's
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Have three now, one is 7 year old, one 5 years old and one three.
When I go by myself I let one run on ground and one on leash for back up.