I also think the likely culprit is the ferret. However, before I personally convict these parents for child desertion et al, I'd need to know more about the ferret and their behavior. A 1 month old baby's toes are quite small and I doubt it would take much for a critter to take them off. How big was this ferret? How sharp are their teeth? How many toes were missing?
I definitely agree with child endangerment by having animals loose around the baby without proper supervision but without knowing more about a ferret's behavior and chewing abilities, as well as the child's specific injuries, I can't go further than that. I'm not assuming that it took several minutes for the ferret to injure this child.
As for the pit bull comments, one rarely sees newspaper stories about poodles or daschunds biting children. It's not exactly sensational. Although, there was that pomeranian that killed a newborn baby a few years ago. Let's ban poms!
The toes were there, somewhere, because the TV news accounts said they tried to reattach them, but couldn't.
ferret links
http://www.peteducation.com/article.cfm?articleid=527 Do ferrets really eat babies?
There have been some highly publicized incidents where a young infant left alone with a young ferret has been seriously injured or killed, and because of this, extremists have claimed that ferrets are not suitable pets for anyone, with or without children. Some of the 'ferrets' in these incidents have actually been ferret-polecat crosses. Wild polecats and hunting ferrets eat baby rabbits, groundhogs, rats, and mice that they find in burrows: it is natural for them to attack milky-smelling creatures. In the few cases where human infants have been attacked by ferrets, both the ferrets and the babies appear to have been neglected by the adults who should have been responsible for them.
An infant should never be left alone with a ferret or with any other animal. Many mature ferrets are entirely trustworthy with the young members of the household, sharing nap time and never taking the slightest nibble at clutching baby hands. You must take responsibility for supervising both the baby and the animal, making sure that neither one hurts the other in their early encounters.
http://www.petplace.com/small-mammals/how-to-keep-your-ferret-from-biting/page1.aspx
Bare feet can attract a playful ferret like roses attract bees. And more than one ferret owner has stepped out of the shower and right into an ambush – a musky little friend lying in wait to attack the toes.It's not a spiteful attack; it's what passes for ferret fun, especially when his owner starts hopping around on one foot yelling “Ow!” But it is also annoying – not to mention painful. And when the ferret is angry or frightened and really does mean for his bite to hurt, it's even worse.
Ferrets are armed with needle-sharp teeth and while the incidence of serious ferret bites is infinitesimally low compared to dog bites – the Journal of the American Veterinary Medical Association has estimated there are an average of 12 ferret bites per year that require medical treatment – biting is certainly a habit any ferret-owner wants to discourage.
http://www.hsus.org/pets/pet_care/rabbit_horse_and_other_pet_care/hsus_statement_on_ferrets_as_pets.html
Ferrets have sharp teeth and occasionally bite when startled, excited, or handled improperly. Because small children have been seriously injured by ferret bites, The HSUS recommends that children, particularly infants, never be left unsupervised with ferrets (or with any other companion animal).
I watched 5 ferrets for a friend once. I would never ever do it again. They are sneaky nasty little stinkers. They would get out of the cage and attack my dobies and akitas. Their bite is sharp and painful. They steal your sneakers and rings. I wouldn't trust them even in their cage. To leave a ferret out of the cage is stupid. They love to destroy couches and rip up carpets. I know people who love their ferrets and have no problems with them. However they are not a pet I would have. When I worked in the shelter we had many come in because people don't understand all the work it takes to keep them. Plus unless you get them descented they reek. I would say the ferret bit the toes off. I doubt rats were around because the ferret would kill them . They ripped one of my dogs ears really badly before I told my friend to come get them.