Dr. Ian Billinghurst
Father of Raw Feeding
“I start every gut recovery program with fermented foods”
Formulated with Dr. Ian Billinghurst, B.V.Sc.Veterinary surgeon · Creator of the B.A.R.F. diet · Author of four books on natural pet nutrition
What it helps with
- Firmer, more regular stools
- A shinier coat
- Steady energy
- Keeps the gains after the 90-Day Reset
- Less gas and gurgling
- Half the dose of Boost, less per day
- A happier dog at the bowl
- Calmer skin, shinier coat
5.0 14,500+ happy customers
Everyday gut maintenance supplement
Sustain™
For after you use Boost™ for 90 days. Maintain your pet's health with Sustain. These 9 ingredients are the right blend of fermented prebiotics and nutrients for great gut support year round.
Click here for ingredients
Broccoli*, Carrot*, Parsley*, Dandelion Leaf*, Cilantro*, Apple*, Moringa*, Holy Basil*, Plantain*. * = Organic and fermented.
- 9 fermented ingredients
- Made in the USA
- 30-Day Taste Guarantee
What owners notice
What you can look forward to
A healthy gut shows up all over the dog. These are the changes owners tell us about most.
- Firmer, more regular stoolsUsually the first change owners notice.
- Less gas and gurglingA calmer tummy after meals.
- A shinier coat, less itchingSkin and coat follow the gut.
- Steady energyMore spring on walks, and a dog who wants to go.
- Fewer grass-eating walksThe lawn stops looking like a salad bar.
- A happier dog at the bowlMany picky eaters come around once the gut settles.
Every dog is different. Give it 90 days before you judge it.
PREBIOTIC POWERHOUSE
These feed good microbes to stay in your dog’s gut and thrive. Different microbes like different prebiotics. We give the good guys a reason to stick around.
WHY PROBIOTICS ALONE DON’T WORK
Many probiotics don't survive the trip through a dog's gut, and the strains that do rarely settle in. Sustain™ is food-based: fermented whole foods that bring the fiber good bacteria feed on, plus the probiotics and postbiotics fermentation creates, so the gut has something to build on every day.
Why 90 days
Cell turnover takes time. So does a microbiome. Three things happen, in order, when you feed it every day.
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Days 1–30 · Detox
Supports the body's natural detox pathways as the gut adjusts to fermented whole foods. Start low and go slow in week one, then feed the full dose every day.
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Days 30–60 · Inflammation
Supports a healthy inflammatory response as the good microbes settle in. This is when many owners first notice the lawn, the coat or the energy.
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Days 60–90 · Integrity
Supports the integrity of the gut lining as its tight junctions tighten. Judge the results here, not before. If you're not willing to give it 90 days, this product may not be right for you.
What's inside
Every ingredient in Sustain™
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Broccoli
Our backbone green: fiber and vitamins to nourish the gut.
Broccoli
The backbone green in three of our blends. It brings fiber, vitamins and glucosinolates that help nourish a healthy gut.
Found inBoost™Sustain™Fiber & Fortifier™
Fermented in Boost™ & Sustain™. Not fermented in Fiber & Fortifier™.
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Cauliflower
Cruciferous fiber, softened by fermentation so more is ready to absorb.
Cauliflower
A cruciferous vegetable with plant fiber and glucosinolates. Fermentation softens its tough cell walls so your dog’s gut can get at more of it.
Found inBoost™
Fermented in Boost™.
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Collard Greens
The one new green in the 18: a hardy leaf, fermented so more of it is ready to absorb.
Collard Greens
A hardy, dark leafy green from the cabbage family. It brings fiber, vitamins and minerals, and fermentation softens its tough cell walls so your dog can absorb more of what it holds. It replaced mustard greens in the current Boost™.
Found inBoost™
Fermented in Boost™.
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Kale
A dark leafy green, gentler and easier to absorb once fermented.
Kale
A dark leafy green full of vitamins, minerals and fiber. Fermented, it’s gentler and easier for your dog to absorb.
Found inBoost™Fiber & Fortifier™
Fermented in Boost™. Not fermented in Fiber & Fortifier™.
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Beet (root)
Earthy, sweet fiber and plant pigments to nourish the gut.
Beet
Earthy, sweet and deeply colored. Beets add fiber and natural plant pigments that help nourish the gut.
Found inBoost™Fiber & Fortifier™
Fermented in Boost™. Not fermented in Fiber & Fortifier™.
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Carrot
A sweet root dogs love, with fiber for steady digestion.
Carrot
A sweet, crunchy root dogs already love. It brings fiber and beta-carotene to support steady, everyday digestion.
Found inSustain™
Fermented in Sustain™.
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Dandelion (root & leaf)
Prebiotic root fiber and bitter greens that support digestion.
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Ginger
A warming root long used to support digestion.
Ginger
A warming root long used to settle and support digestion. A small amount goes a long way.
Found inBoost™
Fermented in Boost™.
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Turmeric
A golden kitchen root for a comfortable, well-supported gut.
Turmeric
A golden root used in kitchens for thousands of years. It brings warming plant compounds that support a comfortable gut.
Found inBoost™
Fermented in Boost™.
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Decaffeinated Green Tea Leaf Extract (decaffeinated leaf extract)
Caffeine-free polyphenols the gut garden can put to use.
Decaffeinated Green Tea Leaf Extract
Caffeine-free green tea brings polyphenols. Fermentation helps turn them into forms the gut garden can use.
Found inBoost™
Fermented in Boost™.
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Holy Basil
An aromatic herb that adds diversity to a steady gut garden.
Holy Basil
An aromatic herb (tulsi) traditionally used for daily balance. It adds plant diversity to a steady, maintained gut garden.
Found inSustain™
Fermented in Sustain™.
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Milk Thistle Seed
A traditional herb seed that supports wellness from the gut out.
Milk Thistle Seed
A traditional herb seed with natural plant compounds. It supports your dog’s overall wellness from the gut out.
Found inBoost™
Fermented in Boost™.
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Moringa
A leafy nutrient powerhouse for long-term gut support.
Moringa
A leafy green known as a nutrient powerhouse, full of vitamins, minerals and amino acids for long-term gut support.
Found inSustain™
Fermented in Sustain™.
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Oregano
A hardy herb that adds aromatic diversity to the gut garden.
Oregano
A hardy Mediterranean herb with aromatic plant compounds (terpenes). It adds diversity to the gut garden.
Found inBoost™
Fermented in Boost™.
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Parsley
A tiny herb packed with vitamins and minerals.
Parsley
A nutrient-dense leafy herb with vitamins, minerals and chlorophyll. It’s a small green with a lot packed in, supporting everyday digestion.
Found inBoost™Sustain™Fiber & Fortifier™
Fermented in Boost™ & Sustain™. Not fermented in Fiber & Fortifier™.
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Apple (fruit & fiber)
Gentle pectin fiber that helps keep things steady. No added sugar.
Apple
Apples bring pectin, a gentle soluble fiber that helps keep stools steady and feeds good bacteria. No added sugar, just the fruit.
Found inSustain™Fiber & Fortifier™
Fermented in Sustain™. Not fermented in Fiber & Fortifier™.
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Blueberry (wild)
Wild blueberries carry more polyphenols than cultivated ones, and good bacteria love them.
Blueberry
Wild blueberries, not the cultivated kind: smaller, more intense, and richer in the polyphenols good gut bacteria love to feed on.
Found inBoost™Fiber & Fortifier™
Fermented in Boost™. Not fermented in Fiber & Fortifier™.
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Papaya
A tropical fruit with natural enzymes that help break down food.
Papaya
A tropical fruit known for its natural enzyme papain. It supports the breakdown of food in the bowl and beyond.
Found inBoost™
Fermented in Boost™.
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Alfalfa Grass
A young, mineral-rich grass, the fresh green dogs go looking for.
Alfalfa Grass
A young, mineral-rich grass. It’s the kind of fresh green many dogs go looking for, and it brings chlorophyll, vitamins and fiber to nourish the gut.
Found inBoost™Youthful Grasses & Sprouts™ dogs & catsFiber & Fortifier™
Fermented in Boost™ & Youthful Grasses & Sprouts™. Not fermented in Fiber & Fortifier™.
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Alfalfa Sprouts
Delicate sprouts picked at peak nutrient density.
Alfalfa Sprouts
Delicate sprouts picked at peak nutrient density, bringing vitamins, minerals and enzymes to nourish the gut.
Found inYouthful Grasses & Sprouts™ dogs & cats
Fermented in Youthful Grasses & Sprouts™.
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Barley Grass
A tender young grass that feeds the gut garden like fertilizer.
Barley Grass
A tender young cereal grass full of vitamins, minerals and enzymes. It nourishes the gut garden like fresh fertilizer.
Found inYouthful Grasses & Sprouts™ dogs & cats
Fermented in Youthful Grasses & Sprouts™.
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Broccoli Sprouts
Baby broccoli, harvested young when it is most concentrated.
Broccoli Sprouts
Baby broccoli, harvested days after sprouting, when the plant is most concentrated. It’s a rich source of sulforaphane.
Found inYouthful Grasses & Sprouts™ dogs & cats
Fermented in Youthful Grasses & Sprouts™.
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Cabbage Sprouts
Young cabbage, sprouted and fermented at its most concentrated.
Cabbage Sprouts
Young cabbage, sprouted and fermented. All the gut-loving goodness of cabbage, concentrated at its youngest.
Found inYouthful Grasses & Sprouts™ dogs & cats
Fermented in Youthful Grasses & Sprouts™.
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Oat Grass
Soft young oat grass, the green many pets love to nibble.
Oat Grass
Soft, sweet young oat grass, the ’cat grass’ many pets nibble on, harvested young when its nutrients peak.
Found inYouthful Grasses & Sprouts™ dogs & cats
Fermented in Youthful Grasses & Sprouts™.
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Wheatgrass
Young wheat grass, cut before the grain, full of chlorophyll.
Wheatgrass
Young wheat grass, cut before the grain forms. It brings chlorophyll, vitamins and minerals in a fresh green your dog can’t get from a bag of kibble.
Found inYouthful Grasses & Sprouts™ dogs & cats
Fermented in Youthful Grasses & Sprouts™.
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Grass-fed Beef
Pasture-raised beef, a familiar protein most dogs already love.
Grass-fed Beef
Grass-fed, pasture-raised beef: a familiar, broadly tolerated protein that brings iron, zinc and B12, and one most dogs already love.
Found inGutAbles®
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Heritage Pork
Real, regeneratively raised protein your dog will work for.
Heritage Pork
Regeneratively raised heritage pork: real, single-source protein your dog will work for.
Found inGutAbles®
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Mānuka Honey (Wedderspoon, organic)
A touch of natural sweetness that holds the treat together.
Mānuka Honey
A touch of New Zealand mānuka honey for natural sweetness and to bind the treat.
Found inGutAbles®
More playful
"We started Gussy's Gut in August. She is more interactive and playful. It is amazing! I was skeptical, as always with a new product. To anyone who is hesitant to try GG: just know that this wonderful concoction is natural and just what our dogs need! We love it."
Trusted by the vets who know
Hear it from the veterinarians
Integrative and raw-feeding vets on why they recommend fermented whole foods for the dogs in their care.
Dr. Steve Marsden
Holistic Vet
“Fermentation is super important if you want to heal a leaky gut”
Dr. PJ Broadfoot
Holistic Vet
“Gussy's Gut Provides the nutrients that dogs need”
Dr. Coward
Holistic Vet
“Gussy's Gut mimics what animals have been eating for 20,000 years”
Dr. Nick Thompson
Holistic Vet
“Fermented vegetables supercharge the gut”
Dr. Eva
Holistic Vet
“I recommend this to all of my clients and they love Gussy's Gut”
Dr. Cathy
Holistic Vet
“Give it 60-90 days to feed the bacteria to fix the gut”
Dr. Matt
Holistic Vet
“The only way pets can get these nutrients is through the fermentation process”
A fair comparison.
Gussy's Gut® vs. a typical probiotic.
A probiotic adds a few strains. Fermented whole foods bring the fiber good bacteria need, plus the probiotics and postbiotics fermentation creates.
| Feature | Gussy's Gut® | Typical probiotic |
|---|---|---|
| What it is | Whole superfoods, fermented | Lab-grown strains in a powder or chew |
| Probiotics | Created by two weeks of fermentation | A few isolated strains |
| Variety of cultures | A diverse mix from 9 fermented whole foods | A few lab-selected strains |
| Food for those cultures (prebiotic fiber) | Built in, from 9 whole foods | Usually not |
| Postbiotics (what good bacteria make) | Made during fermentation | Not included |
| How it's made | Whole foods, fermented together for two weeks | Cultured, then dried |
| Greens, herbs and vegetables | 9 whole foods | Not included |
| Formulated by a vet | With Dr. Ian Billinghurst | Varies |
| How you give it | Stir a spoonful into their bowl | Chew or capsule |
Why variety matters
A healthy gut is a crowd, not a few soloists. Thousands of kinds of bacteria live there, and they work best as a team. Most probiotics add the same few lab-picked strains, scoop after scoop, a bit like planting one crop in the same field every year.
Gussy's works the way nature does. Fermenting 9 whole foods brings a wide mix of cultures, the fiber that feeds them and the postbiotics they make, so your dog's gut gets a whole garden instead of a single crop.
Probiotics help with one problem. Gussy's helps with many.
How much
Half a teaspoon per 20 lb, once a day.
Mix it into food with a splash of water, never dry. Start with a quarter dose and build up over one to two weeks.
| Dog | Per day | 7.5 oz lasts | 90 days needs |
|---|---|---|---|
| Up to 20 lb | 0.5 tsp | 194 days | 1 bag |
| 21–40 lb | 1.0 tsp | 97 days | 1 bag |
| 41–60 lb | 1.5 tsp | 64 days | 2 bags |
| 61–80 lb | 2.0 tsp | 48 days | 2 bags |
| 81–100 lb | 2.5 tsp | 38 days | 3 bags |
| 101–120 lb | 3.0 tsp | 32 days | 3 bags |
| 121–140 lb | 3.5 tsp | 27 days | 4 bags |
. Over 140 lb? Keep the same ratio: one teaspoon for every 20 lb. Email us and we'll size the plan.
How it works
Add, stir, and serve.
1
Measure
½ teaspoon per 20 lb of body weight, once a day.
2
Stir
Add a splash of water and stir it into the food. Never dry.
3
Serve
Kibble, raw or home-cooked. New to it? Start with a quarter of the dose and build up over one to two weeks.
FERMENTATION IS THE WAY
For the same reason dogs bury bones, bury prey, and eat the gut contents of their prey, we ferment. It also makes everything easier to digest and to absorb.
Less per day, on purpose.
When you're in maintenance, Sustain™ is fed at half Boost's dose and costs less per bag, so a day of Sustain costs about a third of a day of Boost. It keeps the work Boost started going, which is what makes it practical for big dogs and multi-dog homes after the Reset.
Doing great at almost 16
"My dog started on this a few months ago. She's almost 16, and would have some soft stool issues more often than I would like. She is doing great!"
HOW GUSSY's COMPARES
*By our master fermentation team and Dr. Ian Billinghurst.
 | Other Brands | |
|---|---|---|
| Nine fermented whole foods | ||
| Organic. 100% Whole Foods. Clean. | ||
| Designed for year round gut support | ||
| Vegetables, fruits, and herbs. |
"This is the single most important upgrade to dog food in over 25 years"
- Dr. Ian Billinghurst, Chief Veterinary Advisor & Formulator
Real dogs, real results
Every review comes from a verified buyer, in the owner's own words. Some reviewers received a reward for reviewing, and those reviews are marked. Boost used to be called Daily, so you'll see that name in older reviews.
Browse by topic
No reviews on this one yet.
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Coat
Lindsay "It's been life changing"
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Itching
Diana "Healthy gut microbiome equals healthy skin microbiome"
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Poop Eating
Veronica "Her poop eating has definitely decreased"
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Energy Levels
Becky "Her energy levels are crazy!"
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energy levels
Tracey "He was happier, his entire demenour changed"
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Stool Quality
David "I immediately noticed stronger consistency with stool quality"
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Stool Quality
Dana "His poop is consistently good"
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Grass Eating
Emma "She hasn't eaten grass in months now"
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Grass Eating
Lauren "I gave it a week and they stopped eating grass"
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Itching
Theresa "She's not scratching anymore!"
Questions
Common questions
Short answers, written by the people who make it. Still stuck? Ask us on the contact page.
How much do I feed?
Half a teaspoon per 20 lb, once a day, mixed into food with a splash of water, never dry. Start with a quarter dose and build up over one to two weeks.
When do I move from Boost™ to Sustain™?
After the 90-Day Reset. Sustain™ keeps the same fermented foundation in the bowl every day, at a lower cost per bag.
Is there a guarantee?
Yes. The 30-Day Taste Guarantee covers one pack if your dog won't eat it, and the 90-Day Reset subscription has a 100-Day Return Policy.
Can I skip, swap or cancel?
Yes, anytime, from your account. Change the delivery date, swap products, or cancel.
The GROW System
Build your dog’s gut garden
Your dog’s gut is like a garden. For it to thrive, the good microbes living there need a healthy place to put down roots. Otherwise they just pass through and never do their job. That’s the problem with most gut supplements.
Gussy’s Gut® is different. Our fermented superfoods are pre-digested, so the nutrients are broken down and ready for your dog to actually absorb. Fed consistently, they help build the kind of healthy garden where good microbes settle in and stay.
Each of our powders does a different job in that garden. Use one, layer a few, or grow the whole thing over time.
GusGut notes from Rob, Gus & Dr. B.
Feeding tips, new batches, and the occasional Gus update. No spam.
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“This is the single most important upgrade to dog food in over 25 years.”
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