Comic Title: Adventures of Rex, the Wonder Dog #45
Publisher: DC (National Comics Publications, Inc.)
Address: 575 Lexington Avenue, New York, NY
Cover Date: May/Jun 1959
On Sale Date: March 5, 1959 Copyright Date March 5, 1959
Source: Library of Congress, Periodicals 1959

Newsstand Date March 5, 1959
Source: Newsdealer Magazine, V14 #2

Frequency: Bi-monthly
Cover Price: $0.10
Page Count: 32
Editor: Julius Schwartz

Title: "The Planet of Giant Dogs"
Pages: 10

Feature(s):
Rex the Wonder Dog (of Earth-1)

Writer: John Broome
Penciller: Gil Kane
Inker: Bernard Sachs

Feature Character(s)

• Rex the Wonder Dog (last appearance in Adventures of Rex, the Wonder Dog #44; next appearance in Adventures of Rex, the Wonder Dog #45)

Supporting Character(s)

• John Rayburn (last appearance in Adventures of Rex, the Wonder Dog #44; next appearance in Adventures of Rex, the Wonder Dog #46)

Villain(s)

• Gordred and Marto (O-Tar's rival and his dog; no further appearances)
• An unnamed hireling (no further appearances)

Other Character(s)

• O-Tar (a dog rider; next appearance in Adventures of Rex, the Wonder Dog #46)
• Lady Elen (also spelled Ellen; a princess; next appearance in Adventures of Rex, the Wonder Dog #46)

Synopsis:
John Rayburn alters his shrinking formula to enlarge people instead. Rex drinks the formula and grows to giant size. He enters a macroverse known as Lamenor where dogs are used as mounts.

Rex meets a dog rider named O-Tar. O-Tar is preparing to enter a dog race, but his dog is injured. Rex offers to let O-Tar ride him in order to win the hand of Lady Elen. O-Tar's rival Gordred tries to cheat his way to victory, but Rex wins anyway. Before he returns to normal size, Rex exposes Gordred and watches as O-Tar wins the hand of the princess.