John and Karen decided that bringing another dog into the family would help when they needed to leave their current dog, Bella, home alone for short periods (the new puppy would be a playmate and keep Bella company).  They wanted a smaller dog as Bella was a medium sized lurcher and they lived in a small house.  Karen found a litter of Jack Russell cross puppies that seemed to perfectly fit the bill and brought their little bundle of cuteness home to meet Bella and the rest of the family.  Bella (a highly prey driven sight hound) immediately viewed this small fluffy bundle as potential prey (not a new friend).  From day 1 the family seemed to spend more of their time protecting their new puppy (Tilly) from her supposed play mate than enjoying time with their family.  Tilly was unable to run freely as Bella chased her every time she moved any faster than a walk.  Bella was considerably larger than Tilly so easily hurt her.  Tilly became snappy with other dogs (not only Bella, but also with any other larger dog).  In the end, the family felt that the kindest thing to do for Tilly would be to rehome her.  Tilly found herself at a shelter with a behaviour issue (snapping and lunging at larger dogs) and the family were heartbroken.

Lurchers and Jack Russell Terriers have been working together for a long time, so this partnership would have worked with appropriate introductions, training and management in place.