Dog Shampoo Ingredients to Avoid: What Every Dog Mum Needs to Know

If you’re anything like me, you want to do the right thing for your dog - especially when it comes to what goes on their skin. Our dogs can’t choose their shampoo or conditioner, and they definitely can’t read ingredient labels… so it’s up to us to make sure the products we’re using aren’t quietly causing irritation, itchy skin, or bigger long-term health issues.

The tricky part? The pet care industry isn’t well regulated, and companies can use ingredients that would never be allowed in clean, human skincare - and often they’re not required to disclose what’s really in their formulas. So even products that claim to be “gentle,” “natural,” “vet recommended,” or “safe for sensitive skin” can still contain harsh chemicals, hormone disruptors, or known irritants.

I’m not sharing this to scare you — but to equip you. Once you know what to look for, choosing safer products becomes really simple. Let’s walk through the main ingredients to avoid, how they impact your dog’s health, and where they most commonly show up.

1. Artificial Fragrances & Perfumes

Look for: “Fragrance,” “Parfum,” synthetic musk.

Common in: Shampoos, conditioners, grooming sprays, colognes, deodorising wipes, scented flea sprays.

These are usually added to make products smell “nice” to us - not to your dog. The problem is that the word fragrance can actually hide hundreds of undisclosed chemicals (including phthalates, which mess with the hormone system).

Because dogs have incredibly sensitive noses, synthetic fragrances can cause:

• Itchy skin

• Sneezing

• Runny eyes

• Anxiety or overstimulation

• Headaches (yes, dogs get them too)

And over time, some of the chemicals used in fragrance blends have been linked to kidney and liver stress. If a product says “fragrance” without listing where the scent comes from (like lavender oil, chamomile or coconut), it’s a definite no.

What to use instead: Botanical hydrosols (e.g., lavender water, chamomile water), fragrance-free formulas.

2. Parabens

Look for: Methylparaben, Propylparaben, Butylparaben.

Common in: Shampoos, conditioners, leave-in detanglers and grooming sprays.

Parabens are preservatives used to extend shelf life, but they mimic oestrogen, which can interfere with normal hormone function over time.

In dogs, this can look like:

• Skin irritation

• Reproductive issues

• Behaviour or mood changes

• Potential cancer risk with repeated exposure

Because dogs groom themselves, anything left on the coat is easily licked and absorbed.

What to use instead: Anhydrous formulas (no water so no preservatives needed), or natural preservation systems like radish root ferment or rosemary extract. Natural preservation systems are generally very gentle and support skin balance, but dogs with inflamed or compromised skin may experience sensitivity while the skin barrier is healing. 

3. Formaldehyde-Releasing Preservatives

Look for: DMDM Hydantoin, Diazolidinyl Urea, Quaternium-15.

Common in: Shampoos, conditioners, medicated washes, some grooming sprays.

These preservatives slowly release formaldehyde (yes, the same chemical used to preserve specimens in labs). It’s a known carcinogen and a strong skin irritant.

In sensitive dogs, this can cause:

• Redness

• Hives

• Hot spots

• Eye and respiratory irritation

If your dog gets itchy right after a bath, this is a common culprit.

What to use instead: Products using non-formaldehyde releasing preservative systems (natural preservation systems) or no water (anhydrous) formulas.

4. Sulphates (SLS, SLES, ALS)

Look for: Sodium Lauryl/Laureth Sulphate, Ammonium Lauryl Sulphate.

Common in: Shampoos, “deep-cleansing” or “degreasing” washes, some pet wipes.

Sulphates are harsh detergents that create that big, bubbly lather - but they also strip the natural oils that protect the skin.

This often leads to:

• Dryness and flaking

• Dandruff

• Itchiness

• A weakened skin barrier (which makes dogs prone to yeast and bacterial issues)

If your dog gets itchier after baths, sulphates are worth eliminating.

What to use instead: Gentle plant-derived cleansers such as decyl glucoside, lauryl glucoside or saponified coconut/olive oils.

 

5. Cocamide DEA / Cocamide MEA

Look for: Cocamide DEA, Cocamide MEA.

Common in: Everyday shampoos.

These are used to boost foam, but can create nitrosamines, which are linked to irritation and long-term cellular stress. They’re also drying and can exacerbate itchy skin.

What to use instead: Saponified coconut/olive oil cleansing bases (plant-oil soap alternatives) rather than foam-boosting synthetics.

6. Cocamidopropyl Betaine

Look for: “Cocamidopropyl Betaine” or “CAPB”

Common in: “Tear-free” or “sensitive skin” shampoos, conditioners.

This one tends to feel gentle because it’s marketed that way - but it is, in fact, one of the most common causes of contact dermatitis in dogs and humans. If your dog has red patches after a bath, or persistent paw licking/mouth rubbing that follows grooming, CAPB could be the culprit.

What to use instead: Coco glucoside or lauryl glucoside - plant-derived cleansing agents that support the skin barrier without triggering irritation.

7. Ethanolamines (TEA / DEA / MEA)

Look for: “Triethanolamine (TEA)”, “Diethanolamine (DEA)”, “Monoethanolamine (MEA)”, often hidden in names like “Cocamide-MEA” or “TEA-Laureth Sulfate”.

Common in: Emulsifying and foaming shampoos, texture-rich conditioners. These are used to thicken, stabilise and make formulas lather - so they make bath time look luxurious. The problem? They can break down into nitrosamines, which are compounds linked to irritation, organ system stress and potential carcinogenic risk.

If your dog’s skin barrier is already compromised, these ingredients may amplify irritation - even when the formula claims to be “mild.”

What to use instead: Plant-based emulsifiers and surfactants like lecithin, olivate/sorbitan olivate, or simple saponified oils. Keep in mind that while plant-based emulsifiers are generally gentle and skin-compatible, dogs with already irritated or yeast-prone skin may experience dryness or sensitivity while the skin barrier is compromised.

8. Propylene Glycol & Polysorbates

Look for: “Propylene Glycol”, “PPG-”, “Polysorbate-20/80”, “PEG-/PPG-” prefixed names.

Common in: Budget shampoos, conditioning sprays, wipe products. Propylene glycol is a humectant and solvent, but studies show it may irritate skin, increase absorption of other chemicals and has been flagged in pet-product safety guides.

Polysorbates (and ethoxylated emulsifiers) often carry contamination risks (for example 1,4-dioxane) and can destabilise sensitive skin.

What to use instead: Plant-derived humectants, aloe vera, oat extract, plant-based emulsifiers/surfactants.

9. Phthalates

Look for: Usually hidden under “Fragrance”

Common in: Colognes, grooming sprays, scented shampoos, deodorising wipes.

Phthalates help fragrance “stick” and linger. The issue is they’re endocrine disruptors, affecting mood, development and hormone balance.

Because dogs lie on carpets, beds and fabrics, they are constantly exposed.

What to use instead: Products that list a true botanical scent or are fragrance-free; avoid the word “fragrance” unless further detail is given.

10. Isothiazolinones (MIT/CMIT)

Look for: Methylisothiazolinone, Methylchloroisothiazolinone.

Common in: Shampoos, conditioners, and products marketed as “hypoallergenic.”

These preservatives are known to cause intense contact allergies and hot spots - often mistaken for food or seasonal allergies.

If your dog has ongoing “mystery itching,” this may be why.

What to use instead: MIT/CMIT-free wellness/shampoo lines designed for sensitive skin; or anhydrous grooming formulas.

11. Polyethylene Glycol (PEG Compounds)

Look for: PEG-40, PEG-75, PEG-80.

Common in: Shampoos, conditioners, medicated washes.

These help products feel silky - but they are often contaminated with 1,4-dioxane (a probable carcinogen) and can dry out the skin.

What to use instead: Humectants derived from plants or safe ingredients like aloe extract, oat extract or glycerin from plant sources.

12. Mineral Oil & Petroleum Ingredients

Look for: Mineral Oil, Paraffin, Petrolatum.

Common in: Paw balms, conditioners, coat gloss products.

These coat the skin, blocking natural detox and trapping heat and bacteria - which is especially problematic for yeast-prone dogs.

What to use instead: Natural oils & butters: hemp seed oil, jojoba oil, shea butter, coconut oil, calendula infused oil.

13. Artificial Colours/ Dyes

Look for: FD&C Red 40, Yellow 5, Blue 1.

Common in: Whitening shampoos and novelty products.

Added purely for appearance - not function. Many artificial dyes are allergenic and linked to behavioural changes in some studies.

What to use instead: Natural botanicals or mineral safe colourants if needed (e.g., chamomile, purple sweet potato), or skip colourant altogether.

14. Alcohols (Drying Alcohols)

Look for: Isopropyl Alcohol, Denatured Alcohol.

Common in: Colognes, ear cleaners, quick-dry sprays.

They evaporate fast - but pull moisture out of the skin, leading to dryness, irritation and sensitivity.

What to use instead: Alcohol-free hydrosols, aloe vera juice, gentle dog-safe sprays without drying solvents.

15. Silicones & Polyquaterniums

Look for: Dimethicone, Cyclomethicone, Polyquaternium-7/10.

Common in: Whitening shampoos, detanglers, shine sprays.

These create the illusion of a shiny, conditioned coat - but actually seal the skin, trap yeast and bacteria, and create build-up.

What to use instead: Protective botanicals that nourish without sealing skin: hemp seed oil, jojoba oil, aloe vera, plant-based humectants.

16. Optical Brighteners & Whitening Dyes

Look for: Optical Brightener 71, Ultramarine Blue, FD&C Colours

Common in: Whitening shampoos.

They make coats look “brighter” by reflecting light - but can cause photosensitivity and irritation, especially in light-coated dogs.

What to use instead: Gentle botanical brighteners and colour-safe alternatives like kaolin clay, chamomile or apple cider vinegar rinse, purple sweet potato extract or blueberry.

The most empowering thing we can do as dog parents is simply know what we’re putting on our dogs’ skin. Once you start reading the labels, it becomes incredibly easy to spot which products are truly gentle and supportive - and which are just marketed to look that way.

Remember, your dog’s skin is their largest organ. What we put on them does get absorbed, and anything on the coat will almost always be licked. So choosing cleaner grooming products isn’t just about avoiding irritation - it’s about supporting their long-term health and wellbeing.