I suppose that was wiped too, by the BBC. But I rather liked it, if I recall correctly. A dissident from a totalitarian future comes back in time and stores his body in a lock-up garage, whilst his mind goes into the dog of the title, the dog of one of the inevitable group of children who help him. Definitely in Mary, Mungo and Midge territory here of tower blocks and rows of garages. Though I was a very middle-class child, our house backed onto a row of garages belonging to the next road down the hill from us, so somehow this was more my world than the usual BBC fare.
Also fallen down the memory hole is the serial about, gasp horror coo er gosh, a gurl written by Anthony Buckeridge that appeared on Fourth Dimension. What on earth was it called? There also appear to be more Rex Milligan books than I remember having read. As a fully paid up member of middle-class-war it won't surprise you at all that I preferred Rex Milligan to Jennings (no mention of Kim Newman in the Wikipedia article on Jennings, either).
And here there is an MP3 of the 4th Dimension theme, by Paddy Kingsland, of course. Children's program theme or music to be played counting down the 4 minute warning? In the 70s you could never quite tell the two apart.