Houilhan heads a list of 14 riders in the over 45s class, in a record outright field of 53 starters.
The Speedcafe.com-backed rider from Albury in NSW took lead in the veterans class when he finished ninth outright in the opening round of the world championship in Saudi Arabia last month.
Houlihan will ride a Husqvarna this week before switching back to his traditional KTM for the remaining rounds of the championship.
He faces a tough six-strong Italian challenge from Cesare Zacchetti, Francesco Catanese, Fabrizio Macchitella, Alberto Bertoldi, Elio Aglioni and Enrico Tanganelli, while Britain's Barry Howe also holds European hopes alongside Norway's Ola Floene.
The Qatari trio of Sheikh Mohammed Al-Thani, Mahanna Rashid Al-Naimi and Mohammed Al-Kaabi, South Africa's Jaco Anderson and Emirati rider Mohammed Al-Shamsi round off the runners eligible for the Veterans' category.
“The weekend's second round looks like it will be a hot one,” said Houlihan.
“The temps in Qatar are expected to be in the mid 30s, but hopefully we don't have the freezing cold mornings like round one in Saudi.
“I am fortunate to have (my wife) Katie with me at this race, she will definitely make things much easier and will work great with the guys from Saudi Dirt Bike Centre.
“We have only ever transited through Qatar, so it will be great to spend some time here to check everything out.
“When things don't go to plan, which is what usually happens with travel at the moment, it's entertaining to have Katie there with me to sort the problems out.
“My bike is serviced and ready to go and from what I can gather this will be a much bigger event than round one, with many of the Dakar riders now recovered the competition will be taken up to the next level.
“This year has the highest ever entries with quite a few big name riders.
“It will be great to catch up again with a lot of the riders I have raced against and with at Dakar and other events.”
The second round of the championship will be hosted out of Doha.