actually most people that have hunted jags w/ dogs have used open mouth hounds. the Lee brothers used their family line of hounds to hunt jag in Mexico & Brasil and lost a lot of dogs every time. but then so did/does everyone that uses the same technique. i doubt i would use a lot of filas as they are just very heavy built and would take a huge amount of work to get the speed & stamina of hounds. but i would gladly cross a good dog onto some excellent hounds. the results should be less open, w/ heavier bone, thicker skin & heavier muscling w/ little or no loss of scenting ability rather like a heavy hound.