CBC News: How common is it that a dog would attack an infant?

Alan Beck: In the U.S. dogs kill about 20-30 people a year. About half of them are pit bulls. Most of the fatalities tend to be the two extremes, the very old and the very young.

If you look at non-fatal dog bites, yes, they are much more common in children, 6-14 years, because that's when kids and dogs are active. The fatalities tend to be younger, under one or even under two, or a very old person who cannot defend themselves at all.

For a very young person, it even predates childhood activity, so you can't blame it on the victim, although people try. A majority of the fatalities are the younger group.

For non-fatal dog bites, it's kids, then adults in occupational things but they're not fatal bites.

It's hard to imagine how a baby could provoke a dog to attack, so why would this happen?

Alan Beck: If it's an unsocialized dog, or where the dog is not perceiving it as a baby, perhaps it's perceiving it as another dog, even as a prey species.

That's one of the problems with some of the larger working dogs, especially working dogs that aren't socialized with people.

The family in Airdrie, Alta., whose baby was killed by their dog operates a Siberian husky dogsled business. CBC News has blurred their faces in this photo to respect their privacy. (Jessica Burtnick)

You have a dog which just doesn't have any interaction with children and then sees this toddler moving and tries to pick it up, maybe not even to eat it or kill it, but just tries to pick it up and in the process, because of the difference in size and vulnerability, kills the child.

It would be nice to see the whole history of this husky, [to determine if it is] more socially isolated, if it's the kind of thing which should just be a bite but turned out to be fatal, versus a true attack.

With babies, are there any breeds of dogs to worry about?

Alan Beck: Size is usually one of the risk factors.

Except with pit bulls. It's the only medium-sized or small dog that has very high fatality rates. There it's probably a behavioural difference with the breed itself. There, too, young people are the most common victims.

Once you go beyond a 15-pound dog, the pit bulls, you find it's the Rottweilers, the Akitas, the huskies; which is probably just a matter of their jaw size and body size.

Are there any warning signs that an individual dog may exhibit, that parents should be on watch for?

Alan Beck: That's another reason why the pit bull is interesting. Many, many people report that they had no idea, in the pit bull's case, that it's aggressive. While we find in other situations, that if you really talk to the people, you find they actually did have warning.

The dog did growl, it was very protective of maybe clothing or food, was maybe involved in less serious bites. Most dogs do show warnings though very often people don't realize what that kind of growling, or that kind of posturing means.

When you do an interview with the family, especially if they were brought here for dog bites or for being aggressive, you find out that if they had really been looking there was some signs and they should have known it before the first bite.

Huskies compete at the 136th annual Westminster Kennel Club dog show on Tuesday in New York. (Craig Ruttle/Associated Press)

That's common. Not everybody understands all that is going on with animals but most dogs show some signs.

The pit bull or a dog that perceives an infant as a prey species may not show any warning ahead of time. Although if they are a predatory dog, chances are that the family should have known that if they chase rabbits, squirrels or anything else, that dog may make a mistake when looking at an infant, especially if it is new to the family.

We've had a few cases like that, where it was a first child, new to the family and the dog behaved more like a dog than as a pet, which happens.

Given that situation of new parents with a dog and a newborn coming into the house, what would you advise?

Alan Beck: There's a whole literature of what to do, especially if there's a newborn to the family, about introducing the dog; making sure that when the dog and the child are socializing there's someone there; that the dog is socialized.

In other words, that the dog doesn't perceive the newborn as a competitor but as an extension of the family, and that you work together, that you do things together, so that the dog starts sharing those bond behaviours with the child as well as with the mother and father.

There are all kinds of ways of introducing but absolutely under no circumstances, do you ever let a larger dog and an infant have access to each other in any kind of unsupervised way.

You supervise, you keep reinforcing the dog being nice and you share things together, you give the child a treat, you give the dog a treat, and so it all becomes part of a network, because once either a human or a dog is part of a social bond then it is much less likely to attack.