I think people had best see the advert for themselves as the Mail are quite slanted in their coverage of it and don't provide it themselves:
https://www.youtube.com/watch?v=CMp8UiCNYas
I must say, I saw the advert on TV the other night and it honestly never occured to me that there were puppies drowning or that the rabbits were 'dying of thirst' (it cries, but that's as the Dad is talking about a heat weave - so it's clearly just meant to be unhappy). I had to watch it again and I'm really unconvinced a child would be particularly damaged by it, but I tend to give kids a little credit, which other people often don't seem to be so keen on.
It is naked propaganda, though, and I can conceivably understand attacking it from that angle. But there again so are the adverts against benefit fraud.