[Philo Vance]

I realize that many will disagree with this suggestion but you could do worse than to consider a mainstream chicken based food from Hills, Purina (Pro Plan, Purina One, or Beyond), or Royal Canin (I don't really know anything about Iams/Eukanuba). The reason being, say what you will about the relative superiority of the ingredients of "holistic" brands and the supposed inferiority of the ingredients in mainstream brands, their research and quality controls ensure that the mineral balance is kept to reasonable levels. Pro Plan in particular is strict about this.

This is notably not the case with some Blue Buffalo, Evo and Orijen foods, although most dogs can probably handle the higher mineral content that comes along with a higher proportion of meat protein (particularly phosphorus). There's no need to feed a mainstream food forever but especially now that your dog has an issue with excessive phosphorus letting all those board certified nutritionists help you out is a good thing. Now is the time to consider nutrients more important than ingredients, at least until you get the crystals under control.

The same can be said if your vet recommends a prescription food. The ingredients almost always "look bad" but keep in mind that in order to curb/cure certain diet related issues no AAFCO food deemed "Complete and Balanced" can get certain values low enough to provide therapeutic levels. I have found the biggest problem with prescription foods is that my pets have always hated the Hills' products. I've had better luck with Purina Vet diets and Royal Canin.

 

[Philo Vance]

@Philo Vance - <snip> I actually spoke with one of the reps at Orijen and they informed me that I would be hard pressed to find a commercial food with lower than around .8% in phosphorous due to AAFCO guidelines.

I started him on Blue from the breeder because I have been using it for years ever since my yorkie was diagnoses with pancreatitis several years ago and it was the only food that seemed to help keep it under control. He and my miniature schnauzer have been on it for the majority of their lives and have always been healthy (although I know each breed is different). I have actually been focusing more on the nutrients, as you suggested and will likely add extra ingredients (canned meat for protein) once we get the crystals under control.

Both Blue Buffalo Life Protection Large Breed Puppy and Pro Plan Focus Large Breed Puppy have PHO at .8% which is well within the guidelines suggested by the link below. Orijen puppy on the other hand is between 1 and 1.3% which seems a little high. Evo is not normally recommended for large breed puppies due to the relatively high amounts of calcium and phosphorus (1.36% pho). The Zignature lamb is .9% which is also well within the guidelines but keep in mind that this is a minimum amount and Zignature is almost certainly co-packed by someone else so you are trusting that their quality control is strict.

This link may prove helpful: Phosphorus Content in Dog Food - Health Topics - Phosphorus Content in Dog Food - Health Topics

The data goes back to 2013 so the values for specific foods may have changed. I note that for the Pro Plan formulas listed the values are lower now. Also note that the formulas that are consistently lowest in pho, in fact below .8%, are from Science Diet. Now I am not recommending SD and I realize that the reason the pho values are low is because SD is notoriously lower in meat protein, but that's the point: a lot of meat comes with a lot of phosphorus, particularly if the meat used is "human grade" muscle meat. That's why Orijen and Evo have relatively high values. They *do* have a lot of meat protein relatively speaking.

Anyway, I'm sure that you'll overcome this problem and learn a lot in the process. It's good that you have an open mind and aren't trying to impose a rigid ideology on your pup.