Her Royal Highness Princess Bajrakitiyabha Narendiradebyavati was admitted to King Chulalongkorn Memorial Hospital after passing out because of a heart problem, the Royal Household Bureau announced on Thursday.
The bureau said the princess passed out while she was training her pet dogs in Pak Chong district of Nakhon Ratchasima at 6.20pm on Wednesday.
The princess was taken to Pakchongnana Hospital in the district to receive initial treatment under the advice of royal doctors, it said. She was transported by helicopter to King Chulalongkorn Memorial Hospital after her condition was stabilised.
The princess's pets were being trained to compete in the Thailand Working Dog Championship 2022 organised by the Royal Thai Army and being held from Dec 10-19 at the Military Dog Battalion in the district.