Surfactants & the mantle piece
Building on our earlier blog post about the quality & purpose of ingredients in pet shampoo products, we’re going to dive deeper into one of the main ingredients in shampoos for dogs—Surfactants—& how they can impact a little known, invisible layer on your dog's skin.
Ever looked at the ingredient list on the back of a dog/human shampoo bottle? The first 2-4 things on the list are almost always surfactants. They do the ‘shampooing’ in shampoo. Not all surfactants work the same way & how they are combined & balanced in a shampoo is crucial to your dog’s largest organ, the skin—because their skin is not like ours.
What is that invisible layer?
It’s the ‘acid mantle’, a very fine, slightly acidic, protective film sitting on the surface of the skin, made up of sebum {oils secreted by sebaceous glands}, sweat, dead skin cells & the skin's surface microorganisms {the skin microbiome}. This has a pH level, typically around 6-7.5, with most healthy dogs at 6.8+ {cats, horses & rabbits are similar}. The outer skin surface barrier is called the ‘stratum corneum’, & simply, it keeps moisture in & irritants out 🛡️
The pH of this layer plays an important role in regulating the skin's microbiome, structural stability & inflammation, & protecting the stratum corneum from environmental irritants.
The acid mantle:
Protects the stratum corneum {skin's outermost layer} from contaminants, viruses & bacteria by inhibiting growth of pathogenic bacteria & fungi {prefer an alkaline environment}
Supports the skin's beneficial microbial community, which competes with pathogens
Maintains integrity of skin proteins that hold skin cells together
Regulates moisture, holding onto hydration by absorbing water & slowing how fast it evaporates out of the skin
Note: If your dog has a skin condition, the acid mantle can be a factor, so it's worth chatting with your vet [1, 2].
What's a surfactant?
Surfactants are active agents that work on the surface of things—such as fabric, skin & hair. They are responsible for the cleansing properties of your favourite shower products. Each surfactant molecule has a 'water-loving head' & an 'oil-loving tail'. Drop them into water & they arrange themselves into tiny spheres called ‘micelles’, tails tucked inward, heads facing out into the water.
What happens every time you bath your dog…
Those oil-loving tails are magnetically drawn to the sebum, dirt & debris {let’s collectively call that 'grime'} sitting on your dog's fur & skin. The tail buries itself in the grime, the water-loving head stays facing outward, & the whole thing gets swept up into the rinse water as one small suspended particle. Do this with billions of micelles at once, & that's why the water running off a dirty dog turns brown—you're literally watching the mechanism of the surfactant work.
Surfactants aren't just cleansers. The same head-and-tail structure makes them useful as emulsifiers, solubilisers, dispersers & wetting agents, which is why you'll see them doing several jobs at once in a single formula.
Through the above mechanism during bath time, the acid mantle is removed. Every bath strips the mantle film away, at least temporarily. That is why what you wash with matters so much. Well-formulated, pH balanced shampoos include ingredients that moisturise & protect the skin while the acid mantle rebuilds itself. The wrong product formula on your dog’s skin works against the restoration process of the acid mantle.
One ‘surfactant myth’ worth busting here: you may judge a shampoo’s effectiveness by its lather, but foam isn't a measure of how well a product cleans. Foam is trapped air—satisfying to use, but not a performance metric. We know people like foam, so you will find lather in a HERDD 3-in-1 shampoo bar 🧼
Why some surfactants are gentler than others
Surfactants fall into four families; anionic, cationic, non-ionic & amphoteric, based on the electrical charge of the water-loving head.
A strongly negatively-charged {anionic} head interacts more forcefully with the skin's own proteins & lipids, which makes it a very effective cleanser—& exactly what makes it capable of over-cleaning if it's too concentrated or too small a molecule. Non-ionic & amphoteric surfactants carry little or no charge.
HERDD’s chemists put this into practice by blending surfactant types deliberately, balancing cleaning power with skin tolerance [3,4].
Why the balance is arguably more important for your dog than you
As our prior post dedicated to pH discusses here, dog skin sits at a higher pH {more neutral to alkaline} than ours {more acidic}.
Dog skin is also thinner than humans & has differently structured hair follicles, making it more prone to injury from the wrong products .
Veterinary reviews note canine skin is often more sensitive than human skin, due to its thinner outer epidermis layer, more neutral pH & hair follicle density. [3]
This is why it’s not a good idea to use human shampoo on dogs, cats or other coated pets. Products formulated for human skin are built to support greater acidity & will harm a pet’s acid mantle. Their skin may pay the price for that over time in the form of itch, dandruff, redness & general irritation. Frequency of washing is also an important consideration; recommendation is no more than 3x per week with a quality product, like HERDD.
The American Kennel Club notes wrong-pH {like using human shampoos} or harsh products can strip protective oils from a dog's coat & skin, leaving it dry & flaky, which can lead to scratching & abrasions where bacteria get in. [5,6]
Synthetic chemical surfactants have a place
Accessible & effective → Harsher surfactants {like SLS, SLES, CAPB} are generally very cheap, effective at cleaning & generate lots of satisfying foam—this is why they're in a lot of pet shampoos, particularly cheaper ones.
Medical use → Vets need to use strong chemical degreasing cleansers {like Chlorhexidine, Benzalkonium Chloride} for anti-septic, anti-bacterial & anti-fungal washes, & though a necessity these can irritate skin.
SLS/Sodium Lauryl Sulfate is the most common surfactant in mass-market shampoos, & the most studied {mostly in human studies}. Research has found SLS binds to & irritates the outer skin layer, & can strip the coat of its natural oils. Resulting observations may include the below skin & coat issues, & be attributed to keratin damage & disruption of the skin's lipid structure {studies have shown SLS can disturb the organisation of the fatty layers between skin cells, increasing water loss through the barrier [7,8]}.
Skin → Dry, flaky, itchy, red/rashes, tight & rough.
Coat → Dull & feel dry, brittle or coarse.
Surfactants used in HERDD’s shampoo
HERDD’s 3-in-1 shampoo bars use two coconut-derived surfactants, chosen as a purposefully balanced pair — the exact blending principle vets recommend, put into practice.
🥥 Sodium Cocoyl Isethionate/SCI is the mild primary cleanser {highest concentration of surfactant}. SCI’s mildness is due to the larger size of its micelles. The size of SCI’s micelles are physically too big to slip through the skin's tiny aqueous pores, preventing them from disrupting the acid mantle barrier. They are mechanically built to stay on the surface, attracting grime & lifting it off skin & fur surfaces.
🥥 Sodium Cocosulfate/SCS is the secondary cleanser {lowest concentration of surfactant}. It provides oil-lifting power needed for a dirty, greasy dog. How SCS differs from harsher surfactants like SLS is due to its composition. SLS is made purely from lauric acid, while SCS is made from the full, balanced range of coconut fatty acid chains. That broader mix changes the surfactant's micelle behaviour & is generally regarded as mild.
Like all ingredients the pH level & the balance of concentration is critical. That's exactly why HERDD’s 3-in-1 shampoo bars are professionally formulated by experienced, senior chemists adhering to strict international regulations, & tested on a range of animals {dogs, cats, horses, cattle}.
How HERDD's unique solid bar formula comes together
Every ingredient we put into our products are purposefully chosen & are naturally derived. Each ingredient added does a distinct job at the molecular level—cleaning, replenishing what the wash lifts, setting the scene for healthy acid mantle repair, & smoothing the fur shaft for optimal comb-ability.
HERDD’s ‘three-function’ formula must haves:
Skin: Healthy & calm → the correct pH range to support restoration of the acid mantle post wash, helping reduce redness, irritation & itch. Moisture is replenished through natural hydrating, emollient & humectant compounds.
Coat: Soft & shiny aka ‘cuddlified’ → Moisturised follicles & strengthened shafts, with plant extracts, emollient & humectant compounds that nourish, condition & detangle fur, manes & tails.
The HERDD 3-in-1 shampoo bar equals:
Why HERDD?
Not all dog shampoos are created equally, & some can cause more harm than cleanliness. When choosing a product for your dog {cat or horse}, be careful to choose brands that put science behind their formulas & manufacturer them to global standards in professional labs.
At HERDD, we are delivering dog & pet owners the highest quality, scientifically formulated wash products that are affordable & made for delicate animal skin. Purrfectly balanced & made to the strictest professional & market-leading laboratory standards in New Zealand, with certified & sustainably produced & sourced raw ingredients.
HERDD 3-in-1 shampoo bars offer value for money & packaged in zero-plastic.
60+ washes with a single multi-function solid bar, for under $19!
