Can anyone shed any light on why 4 males out of 7males in one litter, have either one or two undecended testicles? The sire has both and 2 his previous litters never had this problem, and likewise the dams previous 2 litters never had this problem. Anyone have any ideas please?

I think it's a recessive gene so misses a generation or two before rearing its ugly head again.

I'd had no problems for years and then had 3 in one litter.  When I researched further back, the GrandFather of the CH sire that I'd used was a monorchid.  Of course nobody talked about it until I looked the breeder in the eye and asked! :)  I was disappointed but rehomed the bitch that I'd kept from the litter and never produced anymore.

I wouldn't worry about it yet, my boy is 16 months and his second only descended this past month, there were 9 pups in the litter, 5 boys and only the boy I kept had the undescended one, vet gave him a check up and said everything was 'normal' in that region now.  He was actually booked in for neutering too!

how old are  the puppies? I know of a litter that  had 4 males that only had one testicle when they went to their new homes. the  second could be felt in the inguinal canal and did come down at around 4  months in 3  of the pups. could your pups  just be slow devlopers?
Edited to add,
the sire  had an uncle  that produced  this problem in 2 other litters to different but related bitches.

well I know the males on the sires side for 5 generations and all were OK. I dontknow on the bitches side atall as all overseas. Pups are now 16 weeks.

If this is a recessive trait then both parents would need to have the gene for it. the  sire would produce normal pups to a bitch who doesn't have the gene and the dam would produce normal pups to a sire that didn't have the gene. it is only when a pup inherits the faulty gene from both parents that you get a  pup which shows the fault.
this is what makes some health problems so hard to eradicate. Cryptorchidism is also complicated by the fact that I beleive the females can carry the gene(s) for this but of course they don't show it.
Pups born from a mating with a normal parent and an affected parent have a 50% chance of inheriting the faulty gene,  so a  monorchid dog may produce normal pups, but they would carry the faulty gene.
a dog carrying the affected gene   mated to a dog carrying the affected gene would produce 25% unaffected, 50% carriers  and 25% affected pups.
these percentages are worked out by looking at many different off spring so you might be unlucky and get several affected pups in a litter,  and then next time  get no affected pups. it is just the luck of the draw.
As far as what to do about pups from this litter, boys with both testicles may or maynot have inherrited the gene and the same applies to the girls.  You don't neccessarily need to exclude relatives  from your breeding program but you need to be aware that this problem could crop up again in future litters.
Whilst it  is an irritating fault, it doesn't affect the dogs health to a great extent unlike some health conditions. 
Of course sods law says that  it will be the best looking boy in the litter who only has one ball!!!

It can definitely be carried and passed on, even if the male himself has two testicles that dropped early you can get pups that are missing one or two. I'm also not a fan of using dogs that were late in dropping their testicles (actually that goes for any animal) as you can end up with a line where it just gets later and later, if at all. I'm also pretty certain it can be carried by the bitch so you may have your culprit there if that side is from abroad.
A quick Google found this article: http://www.dogstuff.info/cryptorchidism.html

Pups are now 16 weeks.
Definitely don't start worrying yet.  I knew a breeder with a dog booked for abroad and at 10 months he only had one and so she put him in a pet home here.  He came back to visit at 16 months and he had 2 to be proud of!

unfortunately westcoast she IS worrying NOW as they have all gone to show homes across europe and they are now demanding replacements or refunds!!!

Oh dear. Have to say that I wouldn't send pups abroad without 2 ... but it still is very early days. :(

but surly theres no garentee even when selling to show homes ?

i write this in the contract no guarentee for breeding

i did a search on this subject got one post back stating this person went a semiar in the states
if the left testicles come downfirst then the right will come down to,
but if the right one comes down first the left will not come down,
then there was a back up post stating the same.i dont know how fact this is.?????

you have to ask the owners of the puppies if it the left testicle down

Westcoat which rough collie was that When I bred them years ago I had one after many year of breeding litters and that of course had to be the pick of litter. I was always curious where it came from.

Not to do which the whys and wherefores of undescended testicles, but have discovered a herbal remedy which may help.  One of the girls at my vets told me about this stuff (she breeds a toy breed) which was recomended by a Terrier breeder.  She got one of the vets in the practice to look at it and he said it would do no harm, although no idea why it shoudl work.  She used it on a slightly older pup (I think about 6 months) and it brought the undescended one down.  I used it on my boy spaniel pup who was about 14 weeks, and it appeared within a day or two.  Against the details on the instruction sheet I discontued use before recomended time and it vanished again, so went back on to prescribed use and it has been in place ever since - he is now almost 1.  We also used it for one of my partners boy pugs who was about 5 months and his appeared and stayed down too.  Not a clue why it should work as I am usually sceptical about herbal/homeopathic stuff.  As a bit of an experiment also used it on the Pug boy with only 1 - never been any sign of the 2nd, and it became visible within about 3 days of using this stuff, unfortuatley too late to bring it down itself (he was over 1) but we could find it (yes, he is going to be neutered) for the first time.

The company are called Crossgates Farm, web address is: http://www.crossgatesfarm.co.uk.  Phone number is 0845 130 9618.  You can't order this from the web site, you have to ring them.  It is called, very factually, "Undescended Testicle Remedy".  Follow the treatment advice very closely, it seemed  over complicated at first, but it worked for us.

> "Undescended Testicle Remedy".

I'm loving the imagination that went into that name lol

I was given some tablets for my boy who only had the one, from a very strange homeopathic vet, I think the main ingredient was vitamin E.  His never came down, when he was operated on they couldnt find it, it had never been there in the first place lol !!!

claire was it his right that was down or his left

My boys right one came down first, his left just recently and he's coming up 17 months old, so they can appear.

>claire was it his right that was down or his left

Ive just had a look, it looks like its his left, cant tell really it just swings in the middle ;)

> if the left testicles come downfirst then the right will come down to,but if the right one comes down first the left will not come down,

Pipsqueak, who from birth has "done things differently" appears to be an expception to this rule, his left one was apparent at the usual age, but no sign at all of the right one.  It was not till we used the Remedy stuff that it became apparent, but by then it could not descend itself.

I was told many years ago by an 'oldtimer' in a breed reknown for problems in that area, that you can feel if the testicles in place on a wet newborn male puppy if you turn it over.  I've never been able to find them, but then I've never been very good at finding balls!
Does anyone else feel for them wet?

I'm hopeless at feeling for them even when they are 8 weeks, I can tell there is something there, but not numbers. 

A friend of mine comes and does it for em,a nd she is good at finding them quite early, she has shown me how but it's all Greek to me. 

Just as well I don't keep males.

I'm exactly the same Brainless.  Strange because I'm good at anatomy, veterinary, husbandry, scanning, but when it comes to that bit, I'm completely useless! 
I have 2 friends who just suspend the pup over one arm and feel with the other hand and within 5 seconds they're saying, "Yes 2 no problem!"

i am good at it jenny with the spanish will tell you.

If there's a ball there....I can find it.
I can generally get them at 5 weeks but I wouldn't poke about with newborns so haven't tested that theory.
I've lost track of the number of times I've had to find one for a vet who declared a pup a monorchid.

I had one pup this year with none at 10 weeks.. and I looked I can tell you.......something I've never had.

At 8 months he had them both.

Have to agree with Westcoast...I wouldn't be sending them all over Europe without their testicles.