I suspect it’s more than that.
– people expecting a long term work at home strategy and whose employers have (very) different ideas
– dogs with separation anxiety because for shed loads of time they’ve been in full time company and owners who don’t have the experience or time (see also above) to deal with it
– changes in financial circumstances as furlough unwinds and redundancies bite
– direct Covid impacts like incapacity and illness/death
– idiots who didn’t think about what they were getting into and now want to go back to everything they did before without consequence/complications
I’m sure I’ve forgotten some but I don’t think the reasons are totally straightforward and of course there’s also the fact that a bigger population of owners means a bigger number of giving up enquiries.
What’s probably more informative is trends in % terms of total dog ownership, ages of dogs up for rehoming etc.
Of course the other challenge they will have is that a number of UK rescues have mega tight criteria for adoption and that will (1) fuel the demand for kennel space as they cannot move dogs on / reduces the available adopter population (2) those they’ve rejected before have gone puppy or ‘overseas’ but will add to the general population.
Sadly it’s going to be a bit of a perfect storm for the rescues and they’re going to have to think quite hard about their perfect home/acceptable home criteria and stop/adjust some of the (arguably) more abitrary criteria that have driven the puppy/overseas rescue demand.