Dry food is convenient, affordable, and easy to measure. It is also, for many cats fed exclusively on it, a slow-motion kidney problem waiting to develop.
Chronic kidney disease (CKD) is the leading cause of death in older cats in the UK.1 It is not caused solely by dry food: genetics, age, and other factors play a role. But the relationship between low dietary moisture and feline kidney health is well established in veterinary literature, and it is one of the clearest cases where diet makes a measurable long-term difference.
~10% moisture in dry kibble, versus 70–80% in quality wet food2
CKD affects a significant proportion of cats over 7, frequently linked to chronic mild dehydration1
Why Struvite Crystals Form — and What Causes Them
Struvite crystals are mineral deposits that form in concentrated urine — the kind produced by cats who are not absorbing enough water.3 They can cause painful urination, blockages, and in male cats especially, life-threatening urinary tract obstructions. Feline Lower Urinary Tract Disease (FLUTD) encompasses several of these conditions and is disproportionately common in cats fed dry-only diets.
A high-protein, low-carbohydrate diet naturally produces less concentrated urine. Wet food, for the same reason, is one of the most consistently recommended dietary changes by vets managing urinary conditions.
"We do not say this to alarm anyone who feeds their cat dry food. We say it because the research is consistent and the intervention — adding wet food — is simple." — Nine Lives Club
What you can do now, practically:
Switch the primary meal to wet food, even if you retain dry as a supplement or treat.
If your cat prefers dry, try adding warm water or low-sodium broth to increase moisture intake.
Use a pet water fountain — running water demonstrably increases feline drinking behaviour.4
Place water bowls in multiple locations, away from the food bowl.
If your cat is over seven, ask your vet about annual kidney function blood tests. Early detection changes outcomes significantly.
Our Position: Every tier of the Nine Lives Club box includes wet food with 70%+ moisture content. We include dry food in Box 2 and Box 3 as a complement, not the primary meal. Kidney health is part of why we built the box the way we did.
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