I can quite understand why you all advise prospective puppy purchasers to only buy puppies that have had all the relevant health tests carried out.  But perhaps someone could tell me what happens to the puppies that do not pass these tests?  There are bound to be some from responsible breeders that do not.  Many thanks.

Nope, people here advise folks to buy puppies from people who have had the relevant health checks carried out on the parents of the pups :)

As the previous poster has said, we do advise puppy buyers to buy from responsible breeders who have taken the time and trouble to health test the mother of the litter and have used a stud dog to sire the litter which is also tested. Some breeds do have puppies which should be tested before sale for example it might be a collie puppy which should be tested for CEA before the age of 14 weeks.

Even the best and most responsible breeders do get the odd puppy which fails a health test. This is because there are some problems which the inheritance pattern of the problem is unknown so several generations of dogs which have passed clear can suddenly produce a puppy which is affected. What these breeders do is consult the vets and take their advice, if for example it is a problem which will severely affect the pups quality of life it might be put to sleep. If the problem is not so bad, then the breeder will either keep the pup themselves, or home it very carefully perhaps with a friend or with a family to whom they will have explained very carefully what the condition is, how it is likely to affect the pup during it's lifetime and they will keep in touch to make sure the owner is coping and the pup is well cared for.

Some problems appear much later long after the puppy has already been sold and is settled in it's new home. A responsible breeder will in that case prefer to have the owner contact them about this and will try to help in any way they can. I would also advise people thinking of buying a puppy to ask the breeder what they would do if something did affect the puppy after purchase. 

Im a little confused.....

A responsible breeder tests the ADULT dogs, there arent that many things you can test for in a pup, liver shunt is one thing, and there are a few others obviuosly, but the majority of the 'problems' are tested for in the parents to avoid them being passed on to the pups.

Somethings, such as Hip Dysplasia can be tested for in the parents, and the hips scored, but is not soley hereditary, and cannot be tested for until the pup has finished growing.

Responsible breeders test for all the things they can test for, if they do not, then they are not a responsible breeder and id recommend you do not buy a pup from them.
Same goes for pups that have not had necessary tests done.

I believe that most of the things a pup can be tested for, at a very young age, ie before it leaves the breeder, are pretty serious and/or fatal.

Em