Ingredient file // Flavor
Thyme
A seasoning herb with unproven health perks
Thyme is a culinary herb added to dog food in small amounts for its aroma and flavor. It contributes too little fiber or protein to shape the diet, and studies of its extracts do not show that thyme in food protects dogs from disease.
- What it is
- The leaves and flowering tops of a culinary thyme plant, usually dried before they enter dog food.
- Made from
- Thyme leaves and flowering tops
- Main job
- Herbal flavor and aroma
- Typical amount
- Two published recipes list 0.05% and 0.1%
- Watch for
- Do not confuse the herb with concentrated oil
- Not the same as
- Spanish thyme
Our read // In our catalog
In 1 of every 52 foods we track
Share of foods that list it
2%
50 of the 2,595 foods with an ingredient list on file, from 11 brands. 37 wet dog food, 11 dry dog food, 2 dog food topper.
Each square is 1% of the catalog
Where it sits on the label
Median position 21. In the top five of 0 foods, so it is usually a minor ingredient.
Above the salt
Usually listed after the salt, which caps it at roughly 1% of the recipe in 94% of foods.
Price per lb
Median of the cheapest bag price across 6 priced foods, 24% above 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 Merrick. 11 brands use it in total.
What it is
How it is made
Herb growers harvest thyme for seasoning. Drying makes the leaves and flowering tops easier to store, while cleaning and milling prepare the crop for use in a food recipe.5
- 01 // Source Thyme crop Leaves and flowering tops are harvested from thyme plants grown for culinary use.
- 02 // Process Cleaned and dried Processors remove foreign material and dry the harvested herb to make it suitable for storage.
- 03 // Process Rubbed or milled Dried plant material is broken into smaller, more uniform pieces for mixing into food.
- 04 // Output Dried thyme The prepared herb reaches the food plant as leaves or a milled seasoning.
What is in it
Composition, dry matter
21
% crude fiber
One dried thyme sample contained about 21% crude fiber. At the amounts declared in dog recipes, it adds little to the food's fiber.
Why it is in the bag
What the manufacturer gets
-
01
Adds herbal flavor
Thyme's aromatic compounds give the recipe a recognizable herbal note. The dried herb standard describes flavor and aroma as defining qualities.5
-
02
Seasons a large batch
Published dry and wet dog recipes declare only 0.1% and 0.05% thyme. Those small additions provide seasoning without using the herb as a bulk nutrient source.8,9
How much Two published dog food recipes declare dried thyme at 0.05% and 0.1%; these are examples, not an industry average.8,9
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.
-
Owners say
Thyme in food keeps fleas off dogs
Outruns the evidence
Evidence
- Strong
- Some
- Thin
- None
A placebo-controlled trial tested a supplement containing thyme and other herbs in 22 dogs. Flea counts fell, but the maker supported the study, and its mixed formula cannot show that thyme in ordinary food works.1,8,9
-
Brands say
Thyme gives dogs antioxidant protection
Outruns the evidence
Evidence
- Strong
- Some
- Thin
- None
A feeding study in 120 pigs measured changes in oxidation markers with diets containing 1% or 3% thyme. Published dog recipes declare 0.05% to 0.1%, and no dog study isolates a benefit from thyme at those amounts.2,8,9
-
Brands say
Thyme kills harmful bacteria in a dog's gut
Outruns the evidence
Evidence
- Strong
- Some
- Thin
- None
In laboratory plate tests, thyme essential oil inhibited bacteria while the tested plant extracts did not. That result does not show that dried thyme in food treats infection or improves a dog's gut health.3
-
Owners say
Thyme is toxic to dogs
Outruns the evidence
Evidence
- Strong
- Some
- Thin
- None
ASPCA has separate plant listings: common culinary thyme is non-toxic to dogs, while Spanish thyme is toxic. A warning about Spanish thyme does not apply to the culinary herb on a dog food label.6,7
Straight answers
What owners ask
-
Q01
Is it just filler?
No, seasoningThyme has a clear job: flavor. A published dry dog food contains 0.1% dried thyme, far too little for the herb's fiber or protein to do meaningful work in the recipe.2,5,8
-
Q02
Does thyme preserve the food?
No proofThyme oil showed antimicrobial activity in laboratory tests. That does not show that a pinch of dried thyme preserves kibble. One food listing dried thyme also lists separate antioxidant additives.3,8
-
Q03
Is it safe for dogs?
Yes, as herbASPCA lists common thyme as non-toxic to dogs. The culinary herb in food is different from concentrated thyme oil and from the toxic plant called Spanish thyme.4,6,7
Who uses it
Brands, best sellers and the company it keeps
Top brands, by foods that list it
Plus 1 more brand.
Usually listed with, share of the foods that list it
- Chicken 54%
- Carrots 52%
- Brown Rice 30%
- Sunflower Oil 28%
- Dried Egg Product 26%
- Sweet Potatoes 26%
- Chicken Broth 26%
- Potatoes 24%
- Natural Flavor 24%
- Beef 22%
- Salt 20%
- Peas 20%
Our read // On the bag
Read thyme as seasoning, then keep reading
When thyme sits near other herbs toward the end of a list, give it the weight of a seasoning. Judge the food by its main ingredients and nutritional adequacy. The herb's name is no evidence of antioxidant protection, infection control or flea prevention for your dog.
Sources
What we read
Checked October 1, 2026.
- 1 Evaluation of a plant-based food supplement to control flea populations in dogs: A prospective double-blind randomized study
- 2 Effect of Thyme (Thymus vulgaris L.) Used in Diets with Extruded Flaxseed on the Antioxidant and Lipid Profile of the Blood and Tissues of Fattening Pigs
- 3 Evaluation of Thymus vulgaris and Thymbra spicata essential oils and plant extracts for chemical composition, antioxidant, and antimicrobial properties
- 4 Safety and efficacy of a feed additive consisting of an essential oil obtained from the flowering aerial parts of Thymus vulgaris L. and/or Thymus zygis L. (thyme oil) for use in all animal species
- 5 Standard for Dried Thyme
- 6 Toxic and Non-toxic Plants: Thyme
- 7 Toxic and Non-toxic Plants: Spanish Thyme
- 8 Salmon Complete Dry Dog Food with Insect | Novel Protein & Grain Free | Pooch & Mutt
- 9 Verve Grain Free Dog Food | Adult | Salmon & Turkey | Calibra