Unfortunately I've found that very many dog owners can't tell the difference; to them growling is growling and therefore aggression.  There are also the people who think that any contact between a dog's mouth/teeth and a human's skin should be forbidden. Some even know so little about canine body-language that they even think that a play-bow is a precurser to an attack! :rolleyes: I'm not suggesting for a moment that that applies to any of the posters here, but none of us know how much canine experience other people may have. For example, has the OP's SiL (the one having problems with her lab) had many dogs before?

I find that very strange JG as I have always been able to tell the difference.  I think the whole body language shows you when a dog is being aggressive.  Maybe the people you are talking about are another group who should stick to the hamsters! :D

Unfortunately I've found that very many dog owners can't tell the difference; to them growling is growling and therefore aggression.

Sadly yes. I see this all the time. Particularly in children, but also in many adults that either are non dog owners or novice dog owners. Even worse, I've seen dog trainers not being able to tell the difference between a dog being confident and stubborn (and therefore refusing a command) or scared (refusing because of fear).

Sorry if I misunderstood you Floradora, I just interpreted this:

All puppies play with their siblings through rough play, play biting, barking and growling, snapping and growling at humans is not acceptable behaviour

as you meaning no dog must ever growl at a human even if in PLAY, as it was play you mentioned.

There are plenty of sites on the web that state in various ways that:
"The alpha roll, long touted as the "best" of these methods is in reality a last ditch, all out correction. It's what you do to your teenager after he's taken a joyride in your car and totalled it, not when he first asks you for the keys. Being unfair to your dog in this way can create a fear biter, one who has lost all hope of being treated fairly and defends himself the only way he knows how."

Too late to edit to add: Of course you're absolutely entitled to do what you want with your own dog, but suggesting a course of action which is contentious and dubious at best, where a dog has already bitten and drawn blood, may not be altogether wise. You only have to google "Alpha roll dog" and there's any amount of information. The Wikipedia article is particularly interesting.

This also is very informative.

I liked that, have bookmarked it.
I've just let my new puppy :D meet the 5 big dogs (2 Malinos 1 Golden 2 crosses) and it was very interesting to watch how they interacted for the first time.  Ripley who is the alpha of the dogs and an experienced mother wagged her tail and simply stood still with her head and neck above the pup. Pup got the message that she wasn't one of the dogs wanting to play but wasn't being unfriendly either. No problem. Simba the 3 year old Golden was overjoyed and did what he always does -laid flat on his back, belly in air, inviting the pup to jump on him which he loves. Pup immediately treated him like the big uncle he is. Rio the almost 10 month old Malinois bitch did the play bow and invited to play which was accepted happily. The two crossbreeds wagged their tails, sniffed and said hello, then after a while went to lay down in their beds and when pup bounced over to them it was a low growl "I'm resting, leave me alone" and pup instantly knew they didn't want to play but again wasn't intimidated in any way -so Simba and Rio it was for her that she could treat as her best friends. In 5 minutes she knew who was in charge and who she could jump on and who wanted to be left alone for the time being, and there was not a single problem.

Hi Joey,
oh dear.. I really feel for your relatives and Will.
Life with a dog should be a joy and never a chore or worse..frightening, which is how it appears it has become for your SIL.
I would say she and will are not 'speaking' the same language and really you'll go round and round in circles listening to differing view on forums..I'd say spend your time finding a reputable trainer.
Your SIL and Will need a mediator someone to bring them together and get them speaking the same language! getting them to understand each other and start working together happily. :)
Im a suscriber to the methods of Turid Rugaas she is extremely well respected in the dog world and gives workshops internationally, Ive seen her in Canada and once in my Native Norway.
Have a look at her articles..see what you think
http://www.canis.no/rugaas/onearticle.php?artid=2 (scroll to the part about 'slamming doors stage in young dogs')
I really do think though that you should take a look here http://www.apdt.co.uk/ for a good trainer to help out.
Best of Luck, keep us posted...Will and his family can get through this with the right help.
Hope this helps :)