Potassium

Mechanism

Potassium is quantitatively the most significant cation inside the cell and, together with sodium, governs the membrane potential, neuromuscular excitability and the osmotic water balance. Roughage (grass, hay) is generally rich in potassium, so basic supply is usually covered with normal feeding. What becomes relevant are losses via sweat during intense work, heat and long transports — here the horse loses potassium together with sodium and chloride, which is why compensation is made via the electrolyte balance and not via potassium alone.

Cautions

• · Roughage-rich rations usually cover requirement; isolated potassium dosing rarely needed
• · Sweat losses affect sodium/chloride/potassium together — compensate as an electrolyte mixture
• · In the rare hereditary disease HYPP (QH lines) a low-potassium ration is veterinary-indicated — no blanket potassium top-up

Sources