my 8month old westie seems to have a little gap between top and bottom teeth and always has her tongue poking out , is this normal, when i bought her I did check her teeth and they seemed fine , its only since her big teeth have arrived, i am hoping to breed from her in  about 3yrs time, but not if there is something wrong with her mouth.

Westies should have a scissor bite, where the top teeth closely overlap the lower ones. Which teeth are further forward - is she slightly over- or under-shot?

the top teeth are further forward, but not much, does that mean i should not breed from her

I'm not a westie expert, but in most breeds faulty mouths are considered serious, because it is so easy to breed them into a line, and very difficult to get rid of them again. If she's overshot enough for her tongue to stick out my own view would be that she shouldn't be bred from.

As your pup is still growing there is still time for her mouth to change, why not re-assess her in a few months, or you could try asking her breeders advice, they should know how their own line develops and would be best placed to advise.  If her mouth is overshot tho it would be unwise to breed from her as it would be passed on.

when do they get their big teeth ? at what age ?

Dogs start to lose their milk teeth when they are 4-5 months old.  They should have all their adult teeth by the time they are 6-8 months old.  Jaws can keep growing for another couple of months, however.

Stacey

its just my westie has lost her 2 middle bottom teeth , she looks comical...but all she is doing is chewing her toys, i wondered if this had caused it ? she is 4 months old

Four months is the age when they start losing teeth, chewing on something does help to remove them - but they will not fall out until they are ready. 

Stacey

thank goodness for that ...lol... i thought i was doing something wrong , thanks stacey

i would check all of her mouth/teeth to make sure she hasn't got any retained baby teeth that are getting in the way, so mouth not closing correctly.  my retriever has the front 2 incisors almost fused together and very small in relation to others which means that there is a slight gap at front (not big enough to get his yardage of tongue thro' though!