Attempted this multiple times on Darkspear-US.
Pets did not seem to keep the (
Hex of Jammal'an - Spell - World of Warcraft) Hex but they kept the transformation one (
Hex of Jammal'an - Spell - World of Warcraft). The transformation one would stay on, and wear off during my first stampede, and not transform the pets. The actual debuff that causes the pets to do damage doesn't even seem to work in the dungeon itself on all pets. May be pet specific.
If clarification could be provided on when to dismiss pets, and what pets you used to gain the buff, it would be very appreciated!