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Ingredient file // Vitamin or mineral

Manganous Oxide

A needed mineral, with no joint magic

Manganous oxide is a powdered source of manganese added in small amounts to dog food. Dogs need manganese for normal enzyme activity and growth. The ingredient name alone cannot tell you how much manganese a dog absorbs.

What it is
A dry compound of manganese and oxygen used to supply a required trace mineral in dog food.
Made from
Processed manganese concentrate
Main job
Supplies dietary manganese
Typical amount
Not published
Watch for
Impurities in poorly controlled mineral batches
Not the same as
Manganese dioxide

Our read // In our catalog

In 1 of every 14 foods we track

Share of foods that list it

7%

185 of the 2,595 foods with an ingredient list on file, from 15 brands. 171 dry dog food, 14 wet dog food.

Each square is 1% of the catalog

Where it sits on the label

Median position 39. In the top five of 0 foods, so it is usually a minor ingredient.

Top five List position, heaviest first

Above the salt

0%

Usually listed after the salt, which caps it at roughly 1% of the recipe in 100% of foods.

Price per lb

Foods with it $2.90
All foods $3.23

Median of the cheapest bag price across 140 priced foods, 10% below the catalog. The price is the food's, not the ingredient's.

Who leans on it

26%

of the foods that list it are from Nulo. 15 brands use it in total.

What it is

How it is made

A documented feed grade producer dries, grinds and reduces manganese concentrate to make manganous oxide. The finished powder supplies concentrated manganese to mineral premixes used in animal feed.7,9

  1. 01 // Source Manganese concentrate The documented feed grade plant starts with manganese concentrate as its mineral raw material.
  2. 02 // Process Dried and ground The plant dries and grinds the concentrate before it reaches the reduction furnace.
  3. 03 // Process Reduced in furnace Reduction converts the prepared concentrate into manganous oxide for feed use.
  4. 04 // Output Packaged oxide powder The plant packages the finished feed grade oxide, which suppliers describe as a fine powder.

What is in it

Composition, dry matter

60-62

% manganese

A supplier's elemental manganese range for nearly dry powder. It describes the ingredient, not the amount in finished dog food.

Manganese 60-62%8
Manganous oxide 78-80%8
Iron 6%9
Silica 6%9
Alumina 3%9

Manganese is part of the oxide, so those rows overlap. Supplier figures are rounded dry matter approximations because the powders contain little moisture. The minor mineral values describe one supplier's typical product, not every batch.8,9

Why it is in the bag

What the manufacturer gets

  1. 01

    Supplies required manganese

    Formulators add a manganese source to meet the nutrient target for the food's life stage. Manganese supports normal enzyme activity and growth.3,4

  2. 02

    Concentrates a small dose

    Feed grade powder contains about 60 to 62% manganese. Its high concentration lets a premix deliver a trace nutrient without adding meaningful bulk to the recipe.6,8

  3. 03

    Produced at scale

    A documented feed grade plant produced about 9,000 tons of oxide annually from manganese concentrate. That scale makes it a practical bulk input for mineral premixes.6,7

How much No standard recipe amount is published; formulators account for manganese from the whole diet when setting the oxide addition.3,4

Our read // The claims

What the evidence supports

Strong: controlled studies in dogs agree. Some: small or mixed dog data. Thin: mechanism or lab work only. None: nothing, or the evidence points the other way.

  1. Brands say

    Manganous oxide supplies manganese dogs need

    Evidence

    1. Strong
    2. Some
    3. Thin
    4. None

    An EFSA appraisal of a manufacturer dossier judged the oxide an effective manganese source for animals. AAFCO sets 5 mg/kg dry food as the adult maintenance minimum. Neither source measures oxide absorption in dogs.3,4

  2. Brands say

    Chelated manganese always absorbs better than oxide

    Outruns the evidence

    Evidence

    1. Strong
    2. Some
    3. Thin
    4. None

    In a controlled broiler study, oxide gave 83% of sulfate's bone manganese response in older birds, while a proteinate gave 125%. Those results do not prove that a chelate always benefits dogs eating complete food.1

  3. Brands say

    Manganous oxide prevents joint disease

    Outruns the evidence

    Evidence

    1. Strong
    2. Some
    3. Thin
    4. None

    EFSA links manganese deficiency with skeletal abnormalities, and AAFCO sets an adult minimum of 5 mg/kg dry food. A nutrient requirement is not evidence that adding this oxide prevents arthritis in a dog already eating an adequate diet.3,4

  4. Owners say

    Industrial manganous oxide makes kibble toxic

    Outruns the evidence

    Evidence

    1. Strong
    2. Some
    3. Thin
    4. None

    The 2013 EFSA appraisal judged manganous oxide safe as a feed source within authorized total manganese limits. Its inhalation and irritation warnings concern people handling concentrated powder, not dogs eating a properly formulated food.3

Straight answers

What owners ask

  1. Q01

    Is it just filler?

    No

    It supplies manganese, a nutrient required in complete dog food. Minerals belong among the small additions near the end of an ingredient list. This powder is not there to bulk up kibble.4,6

  2. Q02

    Is sulfate better for dogs?

    Not proven

    Oxide gave a weaker bone manganese response than sulfate in one broiler study. That comparison cannot rank finished dog foods, and the label does not reveal how much manganese a dog absorbs from the complete recipe.1

  3. Q03

    Should I add more manganese?

    Usually no

    Check the nutritional adequacy statement first. A food labeled complete and balanced must meet a nutrient profile or pass a feeding trial. Seeing manganous oxide on the list gives no reason to add another supplement.5

Who uses it

Brands, best sellers and the company it keeps

Top brands, by foods that list it

  1. Nulo 49
  2. Nutro 41
  3. Horizon 25
  4. Bil-Jac 20
  5. Tiki Dog 14
  6. Artemis 6
  7. Taste of the Wild 6
  8. I and Love and You 6
  9. Iams 5
  10. Hungry Bark 4

Plus 5 more brands.

Amazon best sellers that list it

  1. #42 Iams Adult Large Breed Dry Dog Food
  2. #76 Nutro Natural Choice Adult Chicken & Brown Rice Recipe Dry Dog Food

Rank on Amazon's dog food best seller list, checked October 2026.

Usually listed with, share of the foods that list it

  1. Chicken Fat 51%
  2. Chicken 51%
  3. Chicken Meal 45%
  4. Flaxseed 37%
  5. Natural Flavor 34%
  6. Turkey Meal 28%
  7. Peas 26%
  8. Lentils 20%
  9. Turkey 19%
  10. Sweet Potatoes 18%
  11. Canola Oil 18%
  12. Salmon Meal 18%

Our read // On the bag

Read it as a small mineral addition

Manganous oxide belongs near the other minerals at the end of the ingredient list. Judge the main ingredients separately, then check the nutritional adequacy statement for your dog's life stage. The name identifies a manganese source; it does not reveal batch purity or the amount your dog absorbs.

Sources

What we read

Checked September 1, 2026.

  1. 1 Relative biological availability of manganese from manganese proteinate, manganese sulfate, and manganese monoxide in broilers reared at elevated temperatures Poultry Science, 1995 // Journal
  2. 2 Inorganic contaminants and composition analysis of commercial feed grade mineral compounds available in Costa Rica International Journal of Food Contamination, 2015 // Journal
  3. 3 Scientific opinion on the safety and efficacy of manganese compounds (E5) as feed additives for all species: manganous oxide and manganous sulphate monohydrate, based on a dossier submitted by Eramet & Comilog Chemicals S.A EFSA Journal, 2013 // Regulator
  4. 4 AAFCO Dog and Cat Food Nutrient Profiles AAFCO, 2014 // Regulator
  5. 5 “Complete and Balanced” Pet Food U.S. Food and Drug Administration, n.d. // Government
  6. 6 What’s in the Ingredients List? AAFCO, n.d. // Regulator
  7. 7 Resource Efficient and Cleaner Production: Competitive Business - Cleaner Environment - Green Economy UNIDO Resource Efficient and Cleaner Production Demonstration Project in Georgia, 2016 // Nonprofit
  8. 8 TECHNICAL DATA SHEET: Manganese Oxide - Feed Grade Manganese Products Corporation, 2014 // Industry
  9. 9 Manganese Oxide Rohera Minerals Pvt. Ltd., n.d. // Industry
An ingredient on its own tells you very little. What matters is how much of it there is and where it sits in the list. That is why we weigh the top five rather than reacting to any single name further down. Back to the wiki

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