What It Does
The most abundant intracellular mineral, potassium is critical for heart function, muscle contraction, nerve impulse transmission, and fluid balance. Every heartbeat depends on potassium. It works in opposition to sodium — together they create the electrical potential that drives nerve and muscle activity.
What You’ll Notice
Low potassium (hypokalemia) causes muscle weakness — in cats, a classic sign is a head that droops toward the chest because neck muscles can't hold it up. Dogs show general weakness, lethargy, and loss of appetite. Cats with chronic kidney disease lose potassium through increased urination and often need supplementation.
Sources & Notes
Cats with kidney disease frequently develop low potassium. Kidney support diets include extra potassium. Sources: meat, bananas, potatoes, pumpkin. Vomiting and diarrhea also deplete potassium quickly.