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Manganese - Mn in dog and cat diets

A short guide to the role of Manganese - Mn in dog and cat nutrition.

Manganese - Mn

Manganese is essential for the synthesis of glycosaminoglycans — the basic components of joint cartilage, ligaments, and the bone matrix. Without an adequate amount of manganese, the quality of these tissues gradually deteriorates, even when calcium and phosphorus are within range [1]. It is also a cofactor of mitochondrial superoxide dismutase (MnSOD) — the only antioxidant enzyme acting directly within mitochondria — and participates in the metabolism of fats, carbohydrates, and in reproductive function [1] [2]. It is one of the most common silent deficiencies in BARF: a typical meat + bones + liver diet often covers only 30–60% of the standard [1].

Where it's found: Green (uncleaned) tripe, New Zealand mussels, clams, and oysters. Meat, bones, and liver contain practically no manganese — adding offal won't fix it. Note: the composition of mussels is highly variable (species, season, batch), so without the manufacturer's data don't assume that "I added mussels, so the matter is settled" [3].

Deficiency: Growth retardation and skeletal deformities in young animals, loose ligaments, poorer cartilage quality in adults, reproductive disorders, and dulling and reddening of dark coat. Symptoms build up slowly and quietly — a dog or cat may function seemingly normally for years while cartilage and ligaments lose quality. Particularly dangerous in growing large-breed puppies [1].

Excess: Toxicity from food is practically unrealistic due to the low degree of absorption — the surplus is excreted [4]. The only risk is very high supplementation (especially of inorganic forms), which can limit zinc absorption.

Species difference

In cats too, typical BARF (meat + liver + bone) rarely covers the standard, and there is significantly less data on manganese in cats than in dogs [2]. A characteristic trap appears here: a large amount of beef liver (rich in copper) worsens the situation, because excess copper antagonizes manganese absorption — a cat getting 5–7% beef liver is paradoxically sometimes more exposed to a relative manganese deficiency [1]. Don't assume the cat "will manage on its own": in nature it eats the whole prey along with the contents of its digestive tract, and home BARF from "clean" tissues lacks this.

What to watch for

High calcium (bones) and iron (red meat) worsen manganese absorption, which is why manganese sources — tripe, mussels, supplement — are best given in a different meal than bones [1]. In cats there is the added antagonism with copper from liver, see Copper. If you supplement, chelated forms (bisglycinate) are absorbed far better than sulfate or oxide. Be especially careful with the balance in large-breed puppies and pregnant bitches and queens.

Sources

  1. National Research Council (2006). Nutrient Requirements of Dogs and Cats, Chapter 7 — Minerals. National Academies Press. https://nap.nationalacademies.org/catalog/10668/nutrient-requirements-of-dogs-and-cats
  2. Hand MS, Thatcher CD, Remillard RL, Roudebush P, Novotny BJ (2010). Small Animal Clinical Nutrition, 5th Edition. https://www.markmorrisinstitute.org/sacn5.html
  3. Moravszki L, Krizsán J, Freiler-Nagy Á, et al. (2025). Assessment of mineral adequacy in preprepared raw dog foods labeled as complete. Scientific Reports. https://doi.org/10.1038/s41598-025-27388-w
  4. WikiVet contributors. Manganese — Nutrition (WikiVet). https://en.wikivet.net/Manganese_-_Nutrition