Hello Im new to the forum but have been reading your comments and find them very constructive and helpful.
My problem is I have a 5 month Yorkie, he is basically well behaved and is attending puppy training classes.  However, randomly he will attack my mum for no reason we can work out.  He normally mouths when we groom him but this is different he makes a growling noise and really bites, he has drawn blood on several occasions.  I was wondering if it is because he is teething? One of his molars fell out this morning.  I have soaked a piece of cloth and put it in the freezer for him to chew on, as he seems to be chewing like crazy at the mo. Ive just given him an ice cube and hes loving it ha ha

Do you think its teething or is he just crazy?  Any advice openly welcome xx

Opps sorry just noticed visitors questions I think I should have posted on there.....

What does your mum do when he bites and mouthes her? What do you do?

Welcome to the forum :)

My mum has had a stroke so she only has one hand to fend him off, she normally give the firm command NO. This just makes him growl louder and attack again he normally goes for her arms and leaves bruises and nicks in her skin. Then I will put him in the conservatory for a few minutes to calm down, when he comes out he seems to have forgot his agression.

This sounds like over excitement and not aggression.  He is treating your mother as he would a littermate or a raggy toy.  You are doing the right thing by ending the game, if he gets little response and fun out of it it will evetually cease.  It would be a good idea if your Mum could keep some tuggy touys or a suitably sized ball to distract him into more appropriate play.

cheers for putting my mind at rest that this is normal behaviour.  But happens when hes resting or if she goes to stroke him when hes sat near her, not while playing a game or when hes a bit giddy. Is that still exceitment?

We will keep putting him in the conservatory and I will make sure my mum has got a toy by her.  We need another diversion as I will not always be there to put him in the conservatory so the toy sounds like a good plan. Thanks.

About 1 in 1000 puppies will be genuinely nasty. Chances are that your Mum's is one of the 999 rather than that 1000th. It's most likely to be excitement.
:)

If he is being a little swine because she wants to stroke him then I imagine he is getting a bit above himself, especially as I suspect he is up on the sofa. 

In this situation I would unceremoniously tip him off the chair and banish him from the room for his rude behaviour. 

A squirt bottle might well make him clear off when he is being bolshy and trying it on, without your Mum needing to touch him.

Brainless you seem to have hit the nail on the head..... He is on the sofa and I think he believes hes above my mum and seems quite disrespectful to her.  We have considered a waterpistol to stop him when Im not here to put him in the conservatory for "time out".  Cheers to you all it seems hes not a savage after all, he just thinks hes mums boss.  We will have to derank him a bit.

Something that will be quite usueful would be the NILIF program.  This is a non confrontaional way to teadh a dog that your in charge.

Put the letters into Google and you should get several sites with variations on this theme.  The letters stand for Nothing In Life Is Free.  It means that the dog has to do something to earn attention, and the god things in life and can't jsut demand them.

Just read about NILIF this sounds perfect.  He can still be allowed on the sofa or to sleep on the bed but he has to learn that it is on our terms only.  In fact its common sense isnt it, he knows he has to sit for treats or for his ball to be thrown so this is just an extension of what he already knows.  Im going to get my mum more involved in this which will give her higher ranking in his eyes. cheers!

Yep that is exactly the idea, and there is no need for battles of strength, as by doing as he is told he gets what he wants, everyone wins.

I had to tell you, we are sat here laughing our heads off.  He had another go at my mum and we have worked out what it is.  When he takes a ball or toy to her and drops it if she doesnt immediately throw it for him he bites her.  He has just done this and instead of me going and physically putting him in the conservatory I just opened the door and he put himself in there.  Bit of self improvement on his part!

Hi Leanne and welcome to the CD forum :) You were right to post where you did, Visitors Questions is for people to make a one off post when they havent registered ;)