Note that the girls are wearing Sockiplast on their hind paws - all the girls wore them in gym class during the 1970s.
I am showing my age, here ... 😉
Sockiplast is a kind of ankle sock in terry fabrics with a ribbed non-slip plastic sole.
It was launched in 1959 and served instead for sports shoes in gym class ...
43 years of fox comics 1974 - 2017:
http://www.malmerfors.se/foxcomics