Two to 3 - 1"/20ga hypodermic needles are placed in the right flank just behind the costal arch, to relieve gas in the stomach prior to transport to a veterinarian.
The area should be aseptically cleaned prior to performing gastrocentesis with an antiseptic scrub such as Betadine, or at least an antibacterial soap and alcohol.
Remove needles when bulging goes down and the area seems to be near normal. Transport at once to a veterinarian's office. Bring one needle with you in case you are delayed. If so, do it again and remove the needle.