Heart of the Phoenix won't stay on Pet Action Bar.

[Ziarre]

If Heart of the Phoenix is on a Ferocity pet's action bar and you respec that pet, it forgets that it had HotP on the bar and replaces it with something else when you spec back to Ferocity. I have to manually place HotP back on the action bar every time I spec the pet into Ferocity.

And because it's bleepin' annoying, I reported it in the WoW bug forum.

http://us.battle.net/wow/en/forum/topic/6934955050

[Wamo]

In the meantime you can make a macro for it and stick it on your regular action bars. I use:

#showtooltip Heart of the Phoenix
/cast Heart of the Phoenix

Works well!