Ultra-processed dog food is typically manufactured through a series of industrial processes: high-heat cooking, extrusion, etc. They also tend to contain low-quality ingredients like meat derivatives, meat by-products, additives, fillers, preservatives, etc. Research suggests that this kind of processing produces harmful compounds called Advanced Glycation End Products (AGEs), which are linked to excess oxidative stress, chronic inflammation, and diseases including chronic kidney disease. Some studies estimate that, on a metabolic body weight basis, dogs consuming an average ultra-processed diet take in approximately 120 times the AGEs that humans eating a typical ultra-processed diet do. And humans don’t eat ultra-processed food daily, but dogs tend to eat one kind of food every single day. The AGE load, and therefore the chances of chronic kidney disease, becomes even higher in dogs.
Why does this matter?
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Chronic kidney disease (CKD) is one of the most common diseases in older dogs. In geriatric populations, CKD affects up to 10% of dogs, and it can only be managed. When it's caught late, the damage is already done.
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Kidneys are the body's filtration system. Once kidney tissue is lost, it doesn't regenerate. This makes long-term daily diet a much more significant factor than most pet parents realise.
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There is evidence that dietary phosphorus excess may be a risk factor for chronic kidney disease in both humans and pets. Many ultra-processed dog foods are high in inorganic phosphorus, used as a preservative and processing additive.
What do vets generally agree on?
The most critical nutritional modification in kidney disease is phosphorus restriction. Numerous well-designed studies have shown that controlling blood phosphorus concentration through dietary management slows the progression of CKD. Elevated phosphate levels, combined with dysregulated calcium, PTH, and vitamin D, contribute to a complex called CKD-mineral and bone disease. High serum concentrations of phosphate and linked parameters like FGF-23 are associated with increased morbidity and mortality in CKD patients. Moisture is the other major factor. Ultra-processed food contains roughly 8–10% moisture, whereas a fresh, minimally processed diet naturally contains more than 50% moisture. Kidneys need water to filter waste effectively, and low-moisture food may strain them. This is why vets managing CKD almost always prioritise hydration, through wet food, broths, and frequent water intake. Adding hydrating options like BLEP bone broth to dogs’ food or switching to a fresh, minimally processed dog food like BLEP dog food are ways of enhancing moisture in a dog’s diet and lowering AGE load.
When to be careful?
Not every kidney problem in dogs is diet-driven. CKD can also result from genetic predisposition, age, infections, toxin exposure, and other underlying conditions. Several breeds are predisposed to heritable CKD, and prevalence increases significantly from 5–6 years of age onward. If your dog shows signs like increased thirst, frequent urination, reduced appetite, weight loss, or lethargy, these warrant an immediate vet visit, not a diet change alone. Bloodwork measuring creatinine, BUN, and SDMA levels is how CKD is actually diagnosed and staged. Diet matters most as a long-term preventive and a management tool once CKD is confirmed, not as a replacement for diagnosis and treatment. Always work with your vet before making significant dietary changes, especially if kidney disease is already suspected or confirmed.
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