qVeterinary provides a very basic alert when your pet's health drops below a user-defined level. It doesn't include any other fancy pet improvements or controls, but it will work for both Warlock and Hunter pets.

v1.0 - Original
v1.1 - qVet was not restarting properly after exiting and re-logging in, requiring users manually re-start qVet. V1.1 has fixed the initialization function so qVet should remember it's prior state properly (on or off).
v1.2 - qVet really should remember it's prior state properly now. This time for sure!
v1.3 - Adds an audible alarm for low pet health (see readme for details on disabling or changing the sound). Updates the TOC file for 1.9 patch
v30000 - Version number changed to match WoW version numbers. UI panel added in Game Menu | Interface | AddOns. The GUI lets you alter the warning level, change where the messages are sent, and alter the text of the message as well.