my bichon is 8 weeks old and i am feeding her on the same dry food that the breeder had put her on; supadog chicken dry food. However, her poo is runny and yellow and i am not sure what is causing it. She has a tendency to try and eat our other dogs grown up biscuits but i manage to stop her but she may have eaten a few. Is this what is causing it, or is it something else?

If your puppy has only been with you a few days this soft stools often happens and is due to a change in environment (your home has different bugs to the breeders) and the change in water, IMO the change in water is probably the most important factor and for my last two pups I have brought back enough of the breeders water to last 5 days and I have not had this problem.

Still too late for avoiding action, keep to the same food, make sure the pup is not overfed, make sure the pup has a chance to rest and if it has not improved by day 5 from now or the pup seems ill take to the vet. Take immediately if the pup starts to vomit as well as pups can dehydrate very quickly.  It may get worse before it improves.

the yelllow poo only started this morning and i have had her since 27th. She vomits regularly since i picked her up but she is always drinking water. she seems fine in herself...running around and nipping at the older dog!!

So she was about 6 or 7 weeks when you had her? Think I would take her to the vet as this has only just started, it is around this time that the immunity to infection that comes to the pup from the bitch starts to go, so better safe than sorry, take her to see a vet as no pup should be vomiting unless they are eating too much or there is an infection or something else amiss. It is possible that your idea of vomiting and mine are different but I would get her checked out today. One other thing is the poo very smelly?

no sorry she was 8 weeks old when i got her (dont want her to grow up :-)) its not abnormally smelly

I would be more worried about her vomiting a lot and drinking a lot!  She needs to go to a vet quickly in my eyes.

Agree, think a trip to the vet sooner rather than latter is called for, don't wait till Monday.

she has just done another but it has returned to the normal colour. do u think the yellow one was just a one-off? should i still be worried?

A puppy should not be vomiting and the fact that you think that she is drinking a lot still worries me, best to see a vet and be sure, than not and be sorry.

when we got our dog he was vomiting and had runny u know what
he was still running around the place as normal

got so bad went to the vet had loads of antibiotics, turned out he had a something lodged in his intestine.... had a operation!!!!!!!!  it was not nice...

not trying to scare you just want to say when a puppy vomits quite often please take to the vet to avoid further problems.......