My 16 wk old puppies have recently started scratching and knawing for long periods.
They have been seen by vet,have been wormed and frontlined as recommended.They are fed on Royal Canine breed specific puppy food and are growing well.My vet says they are too heavy but they are fed as advised.They are constantly hungry and search and scavenge for food - jumping up to table and now trying to empty bins !!
My problem is which food should l change to ? To try and alleviate this itching ? They are not damaging skin yet but l am worried they may have an allergy to the food.I have another older dog who is not scratching.Any advice gratefully received.

It might be useful to have bit more information:  are you the breeder or the new owner?  More than one puppy?  Same litter?  Both or all with the same symptoms?

If you are the new owner have they always been on this food, from weaning, or have you changed it since you bought them home?  My first thought is that it's more likely to be an external irritant like Frontline, rather than the food - particularly if you've kept them on the same food as the breeder suggested.  When did you apply the Frontline?  Other things to look for are the cleaning products you use and that they are in regular contact with.  Scotchguard on your sofa, biological washing powders, some floor cleaners or air fresheners?

The other thing to consider is where you've been recently - we are in the middle of a season for hay fever in people and dogs or it might be caused by something applied to the fields where you've been walking...

Finally, where specifically are they itchy, scratching, gnawing - this might give us an indicator of the source.  Also what breed are they and did you get them from a reputable breeder?  Some breeds are prone to skin problems and sadly this can be more of an issue with less than reputable sources.

Allergy of this kind are unlikely in a 16 week old pup it is usually an acquired problem.

As has been said are you the breeder and if so is the dam also scratching?

Thanks for reply.l bought boy/girl puppy from a family who were breeding for second time from their much loved golden retriever.They came to me at 7wks and were gradually over a week weaned from paed royal canine to golden puppy food from RC.
Symptoms started 2-3 wks ago,insatiable scratching and knawing.l have an older 9 yr old dog with no symptoms.
They play in our large garden and are only going on 10-15 min road walks at moment.
Their appetite is like nothing l have seen before in dogs - it is like they are starving all the time!
When l took them to the vet last week l was told they were overweight (19kg) at 15wks.l am obviously concerned that l don't let them get fat so give then measured food x3 daily.I am not a breeder but have had dogs all my life and l am now retired.

You may well get some advice about keeping two siblings - not generally a sensible idea and most good breeders don't allow it.  However it's not really relevant to your current issues with itching so I won't go there! :)

I'd be very surprised if it was the food causing the problem - they are so young.  I don't have any experience with RC food although I've always been a bit dubious about their practice of marketing breed specific food.  In most cases (Dalmations being one exception perhaps) the nutritional needs of dogs is the same.  From your comments though overeating might be causing some overheating so a reduction in portion sizes is a good idea.  Forget what you read on the back of the manufacturers bags though as this can be way off for a lot of dogs.  Over time you may well expect the male to eat more than his sister but you'd probably not see much difference in amounts at this stage.  As you are currently doing weigh every portion and keep a record of what you feed - it's far easier to adjust if you know you are consistent with every meal.

When did you apply the Frontline?  Was it the spot on version?  I'm not a fan of this stuff and I don't like it on very young puppies.  There are a number of people on CD that have reported it causing extreme itching and irritation...

One thing you could try - just in case it's an external irritant (inc frontline) is to bath both pups in a very dilute solution of Hibiscrub.  I have a dog with allergies and this a very efficient cleanser to remove pollen and dust from his coat.

Regarding their appetite some pups urge for food isn't entirely related to the amount they eat - they just love food and will try and tell you they are starving all the time.  This breed is known for being 'eaters'!

Would think this is either fleas or mites it is hard to think that they are old enough to have developed an allergy to food. May be washing powder of if you use it carpet cleaning powder or one of the fabric sprays.

Wow - what a minefield,please tell me more about siblings !! Thought l was doing ok with my research ! Obviously not.l am a responsible dog owner and would never do anything knowingly that was not in the best interests of my much loved dogs.
The vet sold the spot on frontline - what is best ?
The vet recommended Royal Canine breed specific.
As a ' responsible' owner l attend puppy clinic fortnightly .
I am totally confused and disheartened with what seems to be misinformation and really don't know where to turn.

Sorry by misinformation l meant from the vet rather than any advice given by members on this forum.

there is an article here about two puppies together: http://www.mastamariners.com/advice_sheets_2_puppies.html and also if you search on this site you will find many posts regarding this issue and why in the majority of cases it is a very bad idea.

Also have you considered what you are going to do when the bitch comes in season?  Despite what many vets will encourage it is not wise to neuter either sex until full skeletal and mental maturity, and on balance best not to neuter males at all. 

This study gives the pros and cons http://www.naiaonline.org/pdfs/LongTermHealthEffectsOfSpayNeuterInDogs.pdf 

Unfortunately your Vets food recommendation is based on the mark up they have on the food and that they sell ti.  It is one of the better foods (doesn't agree with my lot though on it's own).

Did yo puppies have fleas or ticks, if not why did the Vet prescribe Frontline spot on?  Along with others I would only use the spray version on puppies, as it is more dilute (you use more of it all over, rather than a concentrated amount in one place).  My dogs have also reacted to the spot on versions, but been fine with the spray.  Puppies skins are more sensitive.