I'm confused by differing instructions on when to switch to adult food.  My pup is six months old, and some manufacturers say to feed adult food from 6 months (eg. Burns), while others (eg. Arden Grange) tell you to feed the puppy version until 12 months.  Does anyone have an explanation for why this is?  (pup is currently fed on Arden Grange puppy, by the way).

Think it depends on the individual foods. Mine are on Arden Grange and my 9 month old is still on large breed puppy, not sure how much it differs to normal puppy eg. protein etc., May be worth calling them as I have found them very helpful.

Depends a lot on the breed aswell. I have a large breed and always switch to adult food at 6 months otherwise the extra protein affects their coats.

Some puppy foods(especially large breed ones) actually have less protein than the adult version and is often fed until the dog stops growing...
It really depends of the breed and food fed hense different advise given on different brands.

I only fed puppy food untill 5 months, pups breeder nearly had a fit when he found out I had been feeding large breed puppy food (protein levels in large breed puppy food way too high ) He went onto adult food at 5 months.

I was thinking of moving Barney to Arden Grange Prestige once the puppy food runs out (he'll probably be around 7-8 months then, as there's quite a bit left).  Prestige is 30% protein / 20% oil, as opposed to 29% / 18% in the puppy food, but it looks as though you should feed rather smaller quantities, so I guess this means it might not be suitable until he's a bit older?  I posted a few weeks ago as I was worried that he was really skinny - he's improved a lot since I moved him off CSJ to Arden Grange but is still quite "ribbey" looking, so I thought the higher oil content might put a bit more weight on him.  However he's pretty hyperactive, even for a working cocker, and I don't want to make him more so.

It does depend on both the breed and the food but for medium breeds on quality food then I would say 6 to 9 months, to over feed a pup is worse in some ways than to under do it. So if it is well up to weight and doing well start the change at around 6 months taking about a months to accomplish it.

I think it must be breed dependent, I recently changed all of my dogs food over to Arden Grange including my two pups, when I spoke to them they advised that because I had small breeds and at the age they were (both over 6 months) it would be OK to put them on to adult

AG have some good guidelines about moving to adult food when your pup has finished upward skeletal growth - if I remember correctly.  I had conversations with Nessa at AG when I moved my two from Nutro (supply issues), she's very helpful and will be able to send you some literature if you can't get it via their site.

I have a WH Vizsla and, with guidance from our breeder too, we kept him on puppy til he was 12 months then changed to AG Lamb and Rice adult.  One or two of the less mature pups from the litter stayed on puppy for an extra month or two.  I stuck with Nutro for a bit longer as AG didn't offer a lamb version for puppies and I didn't feel I wanted to change protein source unnecessarily but I've always been very impressed with AG food and customer service; the extra info they sent me was very informative when I was trying to find the best food to suit my two.

i kept my ridgeback boy on puppy food until 12months, on advice from a veterinary nutritionist (who also happens to be a good friend, so i know he doesnt mess me around!) he said that he needed the extra calcium until the growth plates closed over ideally. my boy is still quite lean, so the additional calories/fat didnt bother him.

I'm having a similar dilemma - my 8 mo. old toy breed is on both Royal Canin (dry) and JWB (wet).  The JWB says to switch over to adult at 6 months, the RC at 10 mos.  She's only just at the bottom of her adult weight range, so I've decided to keep her on both puppy formulas until 10 mos.  Looking at the ingredient analysis for the JWB, the only difference between the puppy and adult forumulas is .5% of protein, so I don't see this as a problem.

When it was my puppy and dog wanting to share either /or type, I was a bit puzzled about what to do. My vet advised it was better to allow my grown dog to share the puppy food as it was most important for the puppy to have optimum nutrtion and the puppy food would be fine for big dog, but adult food not necessarily so good for puppy.
THis was advised until at least 10 months for my small breed.
Karen ;)

I am currently feeding my pup beta large puppy and am sure I read in all the beta information that they suggest keeping pups on it untl they are two.  I know large breeds take longer to mature but 2 seemed at bit extreme.

I switched my current medium breed over to adult food at approx 8 months.