I noticed on the newest ITV3 editions, the length of the end credits has shortened slightly, this is around the same time the end credits of Corrie more than halved in length, so I'm guessing the length of credits on ITV as a whole must have been cut in mid-1991?
Means we no longer see the dog run accross the whole length of the bottom of the screen at the end of the credits, can play a game on how far he gets across the bottom of the screen (or if he appears at all) before the endcap cuts up as it changed between every episode.
Mid 91 sounds about right for the date that ITV shortened closing credits. I’m sure the new rules stated that half hour shows had to have closing credits no longer than 35 seconds, or similar. That said, it was some years later (c 1993/94) that ITV stopped showing the full end credits of Home and Away. I think the rule didn’t extend to imports (some regions were still screening shows like Sons and Daughters with closing credits well over a minute long).
The BBC brought in similar measures - perhaps a little later - they had to shorten the credits on imports too, such as Neighbours (at one point having to edit a 40-second sequence into 35-seconds!)
Interesting observation about the sheep dog. I remember the two police officers on the end of The Bill used to walk completely out of shot prior to end-credit shortening, but thereafter they barely moved down the street!
CEEFAX SUBTITLES BEGIN SHORTLY