The US edition is 3rd printing. The body of the text seems unchanged to me.
The UK edition has no product code.
Traveller Supplement 2: Animal Encounters – US (GDW) and UK (Games Workshop) editions. 1979 … 44 pages … GDW 305 … no author credited
See Also: Traveller Adventure 6: Expedition to Zhodane (1981) – US (GDW) and UK (Games Workshop) editions