At the End of My Leash Season 4 Episode 10 Canine killers?

Jess and Lukas were devastated when their two dogs killed their pet cat Buddha. Previously the three animals would cuddle and sleep together. They need help to understand how this friendship could turn fatal. With a baby on the way, will they ever know if their dogs are predators or puppies at play? Brad must get to the bottom of the crime if Jess and Lukas are ever to trust their dogs again.