7.3 Urinary Concentration

Urinary concentration is an observable output. In Feline FBM it should be backtraced to renal solute load, Solute Load per Unit Energy, protein energy pressure, and upstream food structure—not directly to drinking water.

Drinking water is a modulation variable, not an upstream cause. Urinary concentration reflects renal handling under solute load.

Do not use “cat drinks little” as the final explanation. Emergency urinary obstruction belongs to the clinical boundary layer.

Solute Load per Unit Energy central renal variable.

From protein energy pressure.

Water intake adjusts output but does not replace structure analysis.

Energy source and mineral structure set load basis.

upstream food structure

↓

solute load per unit energy and protein energy pressure

↓

renal solute load

↓

urinary concentration (observable output / backtrace entry)

↓

hydration modulation (downstream, not upstream cause)

Urinary concentration index is the primary backtrace entry for this output layer. It is not a root cause and not a standalone clinical diagnosis in the Feline FBM layer.