Why is wet food advised for a renal cat?

Why is wet food advised: Because the water it carries helps a diseased kidney that no longer concentrates urine well. A CKD cat loses water through dilute urine and dehydrates. Wet food supplies a large share of daily water needs, supports renal perfusion and limits dehydration. It is a top-up, complementing drinking water (WSAVA, 2020). Expert deep dive ### What water problem does CKD create? The diseased kidney loses its concentrating ability: the cat passes large volumes of dilute urine and compensates poorly by drinking. This polyuria sets up chronic dehydration that lowers renal perfusion and worsens the disease. Supporting water intake is therefore a recognised therapeutic goal (WSAVA, 2020). Wet food steps in where the cat's ancestrally low voluntary drinking falls short. ### What does wet food actually contribute? Wet food holds about 75 to 80% water. For a 4 kg cat needing roughly 200 to 250 ml a day, it covers a notable fraction with no drinking effort. Notable fact: metabolic water and food water count as much as bowl water, which is why a wet-fed cat may drink little without being dehydrated. Wet food does not replace constant access to fresh water, which must be kept available. Comparison table | Mechanism in CKD | Effect | Contribution of wet food | |---|---|---| | Loss of urine concentration | dilute urine, polyuria | offsets water loss | | Chronic dehydration | reduced renal perfusion | supports hydration | | Low voluntary drinking | insufficient water intake | water built into the food | Petipedia's take Petipedia explains the role of food water in CKD as a physiological top-up, complementing drinking water and veterinary follow-up.