in my personal opinion, the dremel for pets is just a cheaply made mass-market item.
if you buy a regular dremel, you get a sturdy, well-made tool, not a flimsy plastic thing. the cordless versions have rechargable battery packs, which is more environmentally friendly (and cheaper in the long run) than using disposable batteries, like the pet tool does.
also, that pet tool has only 2 speed settings, whereas the better dremel models have a variable speed setting that can be adjusted to any speed between 5,000 and 35,000 rpm, which allows you to start on a lower setting to get the pet used to it.
the grinding drums are the same on all models, so when using the regular model there is no more danger for injury than using the pet tool.
if you don't want one of the higher end models, the "mini mite" cordless is still more practical and better made than the pet kit - and the mini mite comes with a rechargable battery pack as well, for about the same price.