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Potassium - K in dog and cat diets

A short guide to the role of Potassium - K in dog and cat nutrition.

Potassium - K

Potassium is the most important intracellular electrolyte — about 98% of the potassium in the body is located inside the cells, while its partner sodium dominates on the outside [1]. Their joint cooperation (the sodium-potassium pump) generates electrical impulses in the body, thanks to which potassium conditions the proper contractions of all muscles (including the heart), nerve conduction as well as water and acid-base balance. The NRC standard for an adult dog is MR 500 mg, RA 1000 mg / 1000 kcal ME; in the cat the RA is higher — 1300 mg / 1000 kcal ME [1].

Where it's found: Muscle meat (beef, poultry, fish) and heart — one of the richest sources of potassium, which in the cat additionally provides taurine [1]. With a balanced home diet, potassium supplementation is not used.

Deficiency: In a properly constructed BARF diet, where meat is naturally very rich in potassium, dietary deficiencies in healthy animals practically do not exist. If the calculator shows low potassium, it almost always means too little muscle meat or too much bone — correct the construction of the recipe and the potassium will fix itself. Clinical shortages are almost always a secondary problem: chronic diarrhoea, vomiting, diuretic drugs, and especially chronic kidney disease (CKD) and hyperthyroidism in cats [2] [3]. Cats have a lower tolerance for potassium fluctuations than dogs — dropping below ~3.3 mmol/l can cause weakness, reluctance to jump, and in more severe cases neck ventroflexion (walking with the head lowered) [2].

Excess: In healthy animals with properly functioning kidneys, the excess of potassium from a meat diet is excreted in the urine on an ongoing basis, so dietary poisoning does not occur. What is dangerous, however, is self-administered supplementation — hyperkalaemia is more dangerous than deficiency and should never be done without blood tests and a veterinarian's recommendation [3].

What to watch for

Do not pour out the juice from thawing meat — potassium is water-soluble and you really lose it in it. If potassium comes out low, check in turn: the share of muscle meat, the share of heart and whether you do not have too much bone. Always consider potassium together with sodium — more about their proportion in the article Sodium : potassium ratio. Diuretic drugs (furosemide) increase potassium losses, and ACE inhibitors (benazepril) can raise it — in an animal on permanent medication the potassium level requires veterinary control regardless of the diet. A cat with CKD may paradoxically lose potassium despite diseased kidneys and need supplementation, but the safe range is narrow and requires strict supervision [4].

Sources

  1. National Research Council (2006). Nutrient Requirements of Dogs and Cats. National Academies Press. https://nap.nationalacademies.org/catalog/10668/nutrient-requirements-of-dogs-and-cats
  2. Dow SW, LeCouteur RA, Fettman MJ, Spurgeon TL (1987). Potassium depletion in cats: hypokalemic polymyopathy. JAVMA 191(12). https://pubmed.ncbi.nlm.nih.gov/3693009/
  3. MSD (Merck) Veterinary Manual. Overview of Disorders of Potassium Metabolism in Animals. https://www.msdvetmanual.com/metabolic-disorders/disorders-of-potassium-metabolism/overview-of-disorders-of-potassium-metabolism-in-animals
  4. Sieberg LG, Quimby JM (2020). Retrospective study of the efficacy of oral potassium supplementation in cats with kidney disease. https://pubmed.ncbi.nlm.nih.gov/31304869/