The reason I made the comparison with cars is that that’s what the original person I replied to used! My point is that a £500 pa dog licence when a dog costs, say £1000 means paying out half the purchase price every year on top of everything else. Dog licence: fine, ridiculous cost of £500 not fine.
So, in the comparison the original poster who mentioned cars used, car owners who’ve sensibly budgeted for petrol, insurance, road tax, etc would be suddenly hit with an extra £10,000 pa on top of those costs (assuming the average car is £20,000 to buy, for ease of Maths).
TLDR: £500 is a ridiculous and unnecessary amount to suggest for a dog licence. The licence is to register dogs not to penalise dog owners who aren’t rich. I remember the dog licence as a very young child. It cost 37p. Today’s equivalent cost would be something like £15 pa.