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Ingredient file // Vitamin or mineral

Monosodium Phosphate

A useful mineral salt with a dose caveat

Monosodium phosphate is a manufactured salt that adds phosphorus and sodium to dog food. It gives formulators a measured mineral source, while short studies of high phosphate diets in dogs raise a question about excess soluble phosphorus.

Role in the food Supporting nutrient
What it is
A water-soluble mineral salt made from phosphoric acid and a sodium source to supply phosphorus and sodium.
Made from
Purified phosphoric acid and a sodium source
Main job
Adds phosphorus and sodium
Typical amount
Not published
Watch for
High phosphorus intake in dogs with kidney disease
Not the same as
Disodium phosphate

Straight answer

Is Monosodium Phosphate safe for dogs?

Read the whole food's phosphorus level

Low on the ingredient list, monosodium phosphate signals a measured mineral addition, but its position cannot tell you the dose. Check the food's phosphorus level if your dog needs a restricted diet; ask the maker when the bag does not provide it. For a healthy dog, judge the complete food before judging this salt.

Why it is in the food
Adds phosphorus and sodium

Our read // In our catalog

In 1 of every 53 foods we track

Share of foods that list it

2%

61 of the 3,204 foods with an ingredient list on file, from 17 brands. 54 dry dog food, 7 wet dog food.

Each square is 1% of the catalog

Where it sits on the label

Median position 20. In the top five of 0 foods, so it is usually a minor ingredient.

Top five List position, heaviest first

Above the salt

22%

Usually listed after the salt, which caps it at roughly 1% of the recipe in 78% of foods.

Price per lb

Foods with it $3.07
All foods $3.25

Median of the cheapest bag price across 45 priced foods, 6% 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 Fromm. 17 brands use it in total.

What it is

How it is made

The feed mineral industry makes monosodium phosphate deliberately. Producers react purified phosphoric acid with a sodium source to make a soluble mineral ingredient that feed manufacturers can measure into a recipe.8,9

  1. 01 // Source Mineral raw materials Purified feed-grade phosphoric acid and a sodium source supply the elements in the finished salt.
  2. 02 // Process Reacted in granulator A commercial producer reacts the materials under controlled conditions to form granules of monosodium phosphate.
  3. 03 // Output Feed-grade granules The finished mineral ships in bags or bulk for measured addition to animal feed.

What is in it

Composition, dry matter

20

% phosphorus

Phosphorus in the feed-table grade on a dry matter basis. A small addition can therefore change a food's mineral balance.

Phosphorus 200 g/kg4
Sodium 160 g/kg4
Ash 100%4
Crude protein 0%4

The salt is sold in different hydrated forms and grades. A commercial feed granule lists 24% phosphorus and 20% sodium, higher than the feed-table grade, so the name alone does not give a precise assay.4,9

Why it is in the bag

There to supply phosphorus and sodium, not bulk

  1. Main nutrition
  2. Supporting nutrient
  3. Does a job
  4. Mostly filler

Formulators add it to reach a phosphorus target without adding calcium. It is about 20% phosphorus and 16% sodium on a dry matter basis, so a modest addition shifts the mineral balance. Lists run by weight, so where it appears low the amount is likely small, but makers do not publish the dose. Its value is the mineral, not bulk. Short dog trials found high soluble phosphate intake disrupted phosphorus markers.2,4,6,8

  1. 01

    Sets phosphorus level

    A concentrated, soluble salt lets formulators add phosphorus without adding calcium. Its amount must fit the finished food's total phosphorus and calcium balance.4,8

  2. 02

    Adds sodium too

    The same addition contributes sodium. It supplies minerals rather than the protein, fat or energy expected from a main ingredient.4

  3. 03

    Adjusts recipe acidity

    FDA lists pH control among this salt's technical uses in food. That describes a formulation function, not a demonstrated health benefit in dog food.5

  4. 04

    Ships at production scale

    Feed-grade granules are sold in bags and bulk, giving manufacturers a measured mineral input. The commercial product sheet offers no price comparison with other phosphorus sources.9

How much An 18-day dog trial used it in a diet with 1.7% total phosphorus on a dry matter basis; usual kibble inclusion is unpublished.2

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

    It supplies phosphorus dogs can absorb

    Evidence

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

    In an eight-dog trial, the diet with soluble monosodium phosphate and soluble calcium had 26% apparent phosphorus digestibility versus 20% for the comparison diet. Both mineral sources changed, so the result does not measure this salt alone.1

  2. Vets say

    High doses disturb a dog's mineral balance

    Evidence

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

    Two short studies from the same research group used eight beagles each. High soluble phosphate diets changed after-meal phosphorus and related blood markers. These were marker studies, not tests of long-term disease.2,3

  3. Owners say

    It prevents bladder stones by acidifying urine

    Outruns the evidence

    Evidence

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

    An eight-dog feeding study recorded after-meal urine pH of 4.9 versus 5.4, but the calcium source changed too. The authors pointed to calcium chloride as an acidifying salt, and the study measured no stones.1

  4. Critics say

    Any amount of it damages kidneys

    Outruns the evidence

    Evidence

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

    The high-phosphorus dog studies lasted 18 days and measured mineral markers, not kidney disease. They support caution about dose but do not show that every food listing monosodium phosphate harms a healthy dog.2,3

Straight answers

What owners ask

  1. Q01

    Is it just filler?

    No

    It supplies phosphorus and sodium, both parts of a food's mineral balance. It contributes no protein or energy. Its usefulness depends on the finished recipe, especially its total phosphorus.4

  2. Q02

    Does it mean extra salt?

    It adds sodium

    The ingredient contains sodium, but its place on the list does not reveal how much sodium is in the finished food. Ask the manufacturer for the food's total sodium if that number matters for your dog.4,6

  3. Q03

    What if my dog has kidney disease?

    Check the diet

    Kidney care calls for controlling total phosphorus intake. Judge a renal diet by its stated phosphorus level and your dog's treatment plan, not by this ingredient's presence alone.7

Who uses it

Brands, best sellers and the company it keeps

Top brands, by foods that list it

  1. Fromm 16 / 67
  2. Verus 7 / 19
  3. Hill's 6 / 116
  4. Tiki Dog 5 / 30
  5. I and Love and You 4 / 23
  6. Blackwood 3 / 7
  7. Hungry Bark 3 / 4
  8. By Nature 3 / 4
  9. Jinx 2 / 21
  10. Annamaet 2 / 20

Foods that list it / all the brand's recipes we track.

Plus 7 more brands.

Usually listed with, share of the foods that list it

  1. Mixed Tocopherols 74%
  2. Chicken Fat 46%
  3. Chicken Meal 41%
  4. Lentils 38%
  5. Chicken 38%
  6. Brown Rice 34%
  7. Flaxseed 33%
  8. Peas 30%
  9. Natural Flavor 28%
  10. Chickpeas 26%
  11. Pearled Barley 25%
  12. Sweet Potatoes 21%

On the shelf

Foods that list Monosodium Phosphate

61 foods in our catalog list it. These 60 list it highest on the label.

Only Natural Pet PowerStew Venison & Duck Feast Grain-Free Wet Dog FoodOnly Natural PetOnly Natural Pet PowerStew Venison & Duck Feast Grain-Free Wet Dog FoodWet // No. 9 on the labelBlackwood Complete & Balanced Diet Lamb Meal & Chicken Meal Dry Dog FoodBlackwoodBlackwood Complete & Balanced Diet Lamb Meal & Chicken Meal Dry Dog FoodDry // No. 11 on the labelWholeHearted Limited Ingredient Diet Duck & Sweet Potato Recipe Dry Dog FoodWholeHeartedWholeHearted Limited Ingredient Diet Duck & Sweet Potato Recipe Dry Dog FoodDry // No. 14 on the labelBlackwood Complete and Balanced Diet Chicken Meal with Ancient Grains & Corn Recipe Dry Dog FoodBlackwoodBlackwood Complete and Balanced Diet Chicken Meal with Ancient Grains & Corn Recipe Dry Dog FoodDry // No. 14 on the labelTiki Dog Aloha Petites for Puppies Chicken, Peas & Lentils Luau Grain-Free Dry Dog FoodTiki DogTiki Dog Aloha Petites for Puppies Chicken, Peas & Lentils Luau Grain-Free Dry Dog FoodDry // No. 14 on the labelHill’s Prescription Diet i/d Puppy Turkey Digestive Care Wet Dog FoodHill'sHill’s Prescription Diet i/d Puppy Turkey Digestive Care Wet Dog FoodWet // No. 15 on the labelVerus VēRUS Canine Advanced Vitality Formula Dry Dog FoodVerusVerus VēRUS Canine Advanced Vitality Formula Dry Dog FoodDry // No. 15 on the labelVerus Canine Core Advantage Formula Dry Dog FoodVerusVerus Canine Core Advantage Formula Dry Dog FoodDry // No. 15 on the labelTiki Dog Aloha Petites Fish Luau Grain-Free Dry Dog FoodTiki DogTiki Dog Aloha Petites Fish Luau Grain-Free Dry Dog FoodDry // No. 15 on the labelI and Love and You Naked Essentials Grain-Free with Chicken + Duck Dry Dog FoodI and Love and YouI and Love and You Naked Essentials Grain-Free with Chicken + Duck Dry Dog FoodDry // No. 15 on the labelPure Balance Puppy Chicken & Rice Recipe Dry Dog FoodPure BalancePure Balance Puppy Chicken & Rice Recipe Dry Dog FoodDry // No. 16 on the labelEvanger’s Grain-Free Meat Lover’s Medley Entree with Rabbit Dry Dog FoodEvanger'sEvanger’s Grain-Free Meat Lover’s Medley Entree with Rabbit Dry Dog FoodDry // No. 16 on the label
Show 48 more
Blackwood Puppy & Performance Growing / Working Dogs Chicken Meal with Ancient Grains Recipe Dry Dog FoodBlackwoodBlackwood Puppy & Performance Growing / Working Dogs Chicken Meal with Ancient Grains Recipe Dry Dog FoodDry // No. 15 on the labelTiki Dog Aloha Petites Lamb Luau Grain-Free Dry Dog FoodTiki DogTiki Dog Aloha Petites Lamb Luau Grain-Free Dry Dog FoodDry // No. 16 on the labelEvanger’s Grain-Free Whitefish and Sweet Potato Recipe with Salmon Meal Dry Dog FoodEvanger'sEvanger’s Grain-Free Whitefish and Sweet Potato Recipe with Salmon Meal Dry Dog FoodDry // No. 16 on the labelBy Nature Turkey & Duck Meal Recipe Dry Dog FoodBy NatureBy Nature Turkey & Duck Meal Recipe Dry Dog FoodDry // No. 16 on the labelVerus VēRUS Canine Small Breed Turkey Formula Dry Dog FoodVerusVerus VēRUS Canine Small Breed Turkey Formula Dry Dog FoodDry // No. 17 on the labelFromm Classic Adult Large & Giant Breed Dry Dog FoodFrommFromm Classic Adult Large & Giant Breed Dry Dog FoodDry // No. 17 on the labelHill’s Prescription Diet w/d Multi-Benefit Vegetable & Chicken Stew Wet Dog FoodHill'sHill’s Prescription Diet w/d Multi-Benefit Vegetable & Chicken Stew Wet Dog FoodWet // No. 17 on the labelNulo MedalSeries Limited+ MedalSeries Limited Ingredient Diet Turkey Recipe Grain-Free Dry Dog FoodNuloNulo MedalSeries Limited+ MedalSeries Limited Ingredient Diet Turkey Recipe Grain-Free Dry Dog FoodDry // No. 17 on the labelHungry Bark Superfoods with Salmon Grain-Free Dry Dog FoodHungry BarkHungry Bark Superfoods with Salmon Grain-Free Dry Dog FoodDry // No. 17 on the labelBy Nature Salmon & Menhaden Fish Meal Recipe Dry Dog FoodBy NatureBy Nature Salmon & Menhaden Fish Meal Recipe Dry Dog FoodDry // No. 17 on the labelVerus VēRUS Canine Senior Advantage Formula Dry Dog FoodVerusVerus VēRUS Canine Senior Advantage Formula Dry Dog FoodDry // No. 18 on the labelTiki Dog Aloha Petites Duck Luau Grain-Free Dry Dog FoodTiki DogTiki Dog Aloha Petites Duck Luau Grain-Free Dry Dog FoodDry // No. 18 on the labelTiki Dog Aloha Petites Chicken Luau Grain-Free Dry Dog FoodTiki DogTiki Dog Aloha Petites Chicken Luau Grain-Free Dry Dog FoodDry // No. 18 on the labelI and Love and You Lovingly Simple Lamb + Sweet Potato Grain-Free Dry Dog FoodI and Love and YouI and Love and You Lovingly Simple Lamb + Sweet Potato Grain-Free Dry Dog FoodDry // No. 18 on the labelHill’s Science Diet Adult Sensitive Stomach & Skin Chicken & Vegetable Entrée Wet Dog FoodHill'sHill’s Science Diet Adult Sensitive Stomach & Skin Chicken & Vegetable Entrée Wet Dog FoodWet // No. 19 on the labelNulo MedalSeries Large Breed Puppy Salmon & Sweet Potato Recipe Grain-Free Dry Dog FoodNuloNulo MedalSeries Large Breed Puppy Salmon & Sweet Potato Recipe Grain-Free Dry Dog FoodDry // No. 19 on the labelVerus Grain-Free Life Virtue Chicken, Lentils & Yams Formula Dry Dog FoodVerusVerus Grain-Free Life Virtue Chicken, Lentils & Yams Formula Dry Dog FoodDry // No. 19 on the labelI and Love and You Baked & Saucy Chicken + Sweet Potato Grain-Free Dry Dog FoodI and Love and YouI and Love and You Baked & Saucy Chicken + Sweet Potato Grain-Free Dry Dog FoodDry // No. 19 on the labelFromm Nutritionals Mobility Chicken & Whole Oats Recipe Dry Dog FoodFrommFromm Nutritionals Mobility Chicken & Whole Oats Recipe Dry Dog FoodDry // No. 20 on the labelI and Love and You Naked Essentials Ancient Grains Recipe with Chicken + Turkey Dry Dog FoodI and Love and YouI and Love and You Naked Essentials Ancient Grains Recipe with Chicken + Turkey Dry Dog FoodDry // No. 20 on the labelFromm Four-Star Rancherosa® Grain-Free Dry Dog FoodFrommFromm Four-Star Rancherosa® Grain-Free Dry Dog FoodDry // No. 20 on the labelJinx : Grass-Fed Lamb for Everyday Nutrition Dry Dog FoodJinxJinx : Grass-Fed Lamb for Everyday Nutrition Dry Dog FoodDry // No. 21 on the labelAnnamaet Manitok Formula Grain-Free Dry Dog FoodAnnamaetAnnamaet Manitok Formula Grain-Free Dry Dog FoodDry // No. 21 on the labelLotus Oven Baked Small Bites Sardine Recipe Grain-Free Dry Dog FoodLotusLotus Oven Baked Small Bites Sardine Recipe Grain-Free Dry Dog FoodDry // No. 21 on the labelLotus Oven Baked Regular Bites Sardine Recipe Grain-Free Dry Dog FoodLotusLotus Oven Baked Regular Bites Sardine Recipe Grain-Free Dry Dog FoodDry // No. 21 on the labelHungry Bark Superfoods with Turkey & Duck Grain-Free Dry Dog FoodHungry BarkHungry Bark Superfoods with Turkey & Duck Grain-Free Dry Dog FoodDry // No. 21 on the labelVerus Grain-Free Large Breed Puppy Chicken, Lentils & Yams Formula Dry Dog FoodVerusVerus Grain-Free Large Breed Puppy Chicken, Lentils & Yams Formula Dry Dog FoodDry // No. 22 on the labelBy Nature Lamb & Turkey Meal Recipe Dry Dog FoodBy NatureBy Nature Lamb & Turkey Meal Recipe Dry Dog FoodDry // No. 22 on the labelHill’s Science Diet Adult 7+ Healthy Cuisine Braised Beef, Carrots & Peas Stew Wet Dog FoodHill'sHill’s Science Diet Adult 7+ Healthy Cuisine Braised Beef, Carrots & Peas Stew Wet Dog FoodWet // No. 23 on the labelAnnamaet The Best Adult Dry Dog FoodAnnamaetAnnamaet The Best Adult Dry Dog FoodDry // No. 23 on the labelFromm Heartland Gold Large Breed Adult Grain-Free Dry Dog FoodFrommFromm Heartland Gold Large Breed Adult Grain-Free Dry Dog FoodDry // No. 23 on the labelFromm Four-Star Pork & Applesauce Formula Dry Dog FoodFrommFromm Four-Star Pork & Applesauce Formula Dry Dog FoodDry // No. 23 on the labelVerus Grain-Free Cold Water Fish Salmon, Menhaden Fish Meal & Herring Formula Dry Dog FoodVerusVerus Grain-Free Cold Water Fish Salmon, Menhaden Fish Meal & Herring Formula Dry Dog FoodDry // No. 25 on the labelFromm Four-Star Pork & Peas Recipe Grain-Free Dry Dog FoodFrommFromm Four-Star Pork & Peas Recipe Grain-Free Dry Dog FoodDry // No. 25 on the labelHill’s Science Diet Adult 7+ Senior Vitality Small & Mini Chicken & Vegetable Stew Wet Dog FoodHill'sHill’s Science Diet Adult 7+ Senior Vitality Small & Mini Chicken & Vegetable Stew Wet Dog FoodWet // No. 26 on the labelJinx Small Breed Grain-Free Atlantic Salmon Dry Dog FoodJinxJinx Small Breed Grain-Free Atlantic Salmon Dry Dog FoodDry // No. 26 on the labelFromm Four-Star Duck À La Veg® Recipe Dry Dog FoodFrommFromm Four-Star Duck À La Veg® Recipe Dry Dog FoodDry // No. 26 on the labelHill’s Prescription Diet ONC Care Chicken & Vegetable Stew Wet Dog FoodHill'sHill’s Prescription Diet ONC Care Chicken & Vegetable Stew Wet Dog FoodWet // No. 27 on the labelHungry Bark Superfoods with Lamb & Turkey Grain-Free Dry Dog FoodHungry BarkHungry Bark Superfoods with Lamb & Turkey Grain-Free Dry Dog FoodDry // No. 27 on the labelFromm Small Breed Adult Gold Dry Dog FoodFrommFromm Small Breed Adult Gold Dry Dog FoodDry // No. 27 on the labelFromm Puppy Gold Dry Dog FoodFrommFromm Puppy Gold Dry Dog FoodDry // No. 27 on the labelFromm Large Breed Puppy Gold Dry Dog FoodFrommFromm Large Breed Puppy Gold Dry Dog FoodDry // No. 27 on the labelFromm Large Breed Adult Gold Dry Dog FoodFrommFromm Large Breed Adult Gold Dry Dog FoodDry // No. 27 on the labelFromm Four-Star Chicken À La Veg® Recipe Dry Dog FoodFrommFromm Four-Star Chicken À La Veg® Recipe Dry Dog FoodDry // No. 27 on the labelFromm Reduced Activity & Senior Gold Dry Dog FoodFrommFromm Reduced Activity & Senior Gold Dry Dog FoodDry // No. 28 on the labelFromm Four-Star Whitefish & Potato Formula Dry Dog FoodFrommFromm Four-Star Whitefish & Potato Formula Dry Dog FoodDry // No. 28 on the labelRoyal Canin Boxer Adult Dry Dog FoodRoyal CaninRoyal Canin Boxer Adult Dry Dog FoodDry // No. 31 on the labelFromm Four-Star Game Bird Recipe Grain-Free Dry Dog FoodFrommFromm Four-Star Game Bird Recipe Grain-Free Dry Dog FoodDry // No. 31 on the label

Sources

What we read

Checked September 1, 2026.

  1. 1 Apparent digestibility and calcium and phosphorus in urine after feeding different combinations of calcium and phosphorus sources to adult dogs Journal of Animal Physiology and Animal Nutrition, 2024 // Journal
  2. 2 Effects of dietary phosphates from organic and inorganic sources on parameters of phosphorus homeostasis in healthy adult dogs PLOS ONE, 2021 // Journal
  3. 3 The Source Matters-Effects of High Phosphate Intake from Eight Different Sources in Dogs Animals, 2021 // Journal
  4. 4 Monosodium phosphate hydrate FG INRA CIRAD AFZ Feed Tables, n.d. // Database
  5. 5 Substances Added to Food: Sodium Phosphate, Monobasic U.S. Food and Drug Administration, 2026 // Government
  6. 6 Reading Labels AAFCO, n.d. // Regulator
  7. 7 Treatment Recommendations for CKD in Dogs International Renal Interest Society, 2023 // Nonprofit
  8. 8 Monosodium phosphate EMFEMA, n.d. // Industry
  9. 9 Monosodium Phosphate - Feed Grade Yara Animal Nutrition, 2015 // 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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