Lottie, my just-about-15-month-old Cocker Spaniel/Cavalier King Charles pup is very adorable, and also extremely fond of getting filthy. She is certainly not a prissy dog! She’s got very fluffy paws, and on warmer winter days when melting snow transforms our local dog park into a mud bath, those paws quickly go from blonde to black. It’s rather cute (everything she does is cute…), but it’s not a good look for my floors. Or, perhaps we’re out in the mountains and she’s found a bit of novel elk poop. What better way to become acquainted with it than to roll in it?! She has an uncanny ability to find foul things and wear them; there’s nothing quite like getting back into the car after a dog walk, shutting all the doors, and almost immediately going “what’s that?!” as some foul stench snakes up my nostrils. Delightful. Anywho—this dog shampoo. It removes stench, is wonderfully easy to steer around a wet and uncooperative dog, and works like a charm.
After I did a bunch of research into the pH of human skin and the importance of the pH of our cleansers, that got me wondering about the pH of canine skin. A bit of research quickly turned up that dog skin has a higher pH than human skin. This range seems to be pretty big; the lowest number I found was 5.5 and the highest was 9.1—it turns out there’s just as much variety in dog skin pH as there is in dogs! Most ranges I found were decidedly more basic than human skin, though, and the tended to average around 7. This means shampoos for dogs should have a pH around 7—quite a bit more basic than human shampoos, but much more acidic than soap.
Dog skin is also quite a lot thinner than human skin—our skin is roughly 2–3x thicker than dog skin! For this reason they are even more prone to irritation, making properly formulated skin care products extra important.The surfactant blend is also quite gentle, comprised mostly of Sodium Cocoyl Isethionate (SCI) and Cocamidopropyl Betaine, with some Sodium Coco Sulfate (SCS) for added canine-cleansing. I’ve also included some panthenol (vitamin B5) to help with skin soothing, some BTMS-50 for conditioning, and some emollient cetyl alcohol and tucuma butter.
Something I made a conscious decision not to include was any sort of essential oil or fragrance. A dog’s sense of smell is “tens of thousands of times” more sensitive than yours, and it just seems a bit mean to make them smell like something they usually wouldn’t. In addition, fragrance oils are often a prime culprit for skin irritation, and many popular essential oils (like tea tree) are poisonous to dogs. I know there are certainly many highly fragranced dog products on the market (I knew somebody who liberally applied a dog-specific strawberry kiwi scented dry shampoo to her dog, who smelled like lip gloss most of the time 😝), so it’s likely not the worst thing in the world, but I prefer to leave my dog stuff unscented.
The first time I made this shampoo bar I used a water bath, but found that it took absolutely ages, and the shampoo remained so thick and sticky that it was really hard to work with. I tried some other surfactant projects over direct heat and that worked really well, so this time I oped for using the stovetop over low heat. I found that really sped up the SCI/Cocamidopropyl Betaine melting time and ensured everything melted together quite a lot faster (BTMS and I have a bit of an ongoing why-won’t-you-melt-until-transparent-in-a-waterbath spat). You are certainly welcome to do everything in a water bath instead (especially if they’ve worked well for you in the past), but if you do decide to join me in the world of direct heat please watch it carefully! It’s easy to get a bit slack on the supervision when you’re used to water baths, which are very forgiving. Direct heat is not forgiving, and we are working with small amounts of things, which heat up very quickly. Make sure you have everything measured out before you turn the stove on as things will move much faster than usual, and you don’t want to walk away from your concoction lest you accidentally fry your dog shampoo.
As written in grams, this recipe will make a 50g shampoo bar, which is plenty for Lottie, who is 10.9kg (24lbs). If you have a big fluffy Bernese Mountain Dog or a Great Dane I’d recommend scaling the recipe up to at least 200g, if not more! I’ve included a link to a batch calculator in the substitutions list at the end of the recipe. Ok—lets get our pooches all sudsy and clean!
Lottie’s Dog Shampoo Bar
1:1 citric acid solution, as needed
Combine the Sodium Cocoyl Isethionate and Cocamidopropyl Betaine in a small saucepan and place over low heat until smooth and uniform, stirring frequently. Ensure the heat is very low! If you have a pre-prepared 3:2 SCI:Cocamidopropyl Betaine paste, you can skip this step and use 25g of that paste instead.
Add the SCS to the SCI/Cocamidopropyl Betaine mixture over the heat and stir to combine, keeping an eye on the mixture as the SCS begins to break down. Weigh the BTMS-50, cetyl alcohol, tucuma butter, and panthenol into a small dish.
Once the surfactant paste is very soft, add the tucuma butter mixture into the surfactant baste and briskly stir to thoroughly combine, continuing to stir as the solid ingredients melt. Once the solid ingredients have melted completely and have been thoroughly incorporated, it’s time to test and adjust the pH—we want the pH of the finished bar to be between 6.5 and 7.5. My bar tested around 8 at first, and adding two drops of a 1:1 citric acid solution brought it down to between 6 and 7.
To test the pH: (Be sure to check out this great article on the importance of diluting solutions when pH testing them—we’re doing that here!) Prepare at least two small bowls by weighing 4.5g of distilled water into them (you’re going to want a scale that’s accurate to 0.01g for this). To make your citric acid solution, weigh 5g of citric acid into a small beaker and add 5g of distilled water. Stir to combine (I also incorporated a couple quick microwave bursts to speed things along).
To test the pH, add 0.5g of the shampoo paste to one of the bowls containing 4.5g of water to create a 10% dilution, and pH check that. It should be around 7/8. I then added 2 drops of the citric acid solution to the main batch of shampoo, stirred that in, and re-tested it—it was around 6/7.
Keep stirring the mixture as it cools—this bit is a titch tricky. We need the mixture to be cool enough to add the preservative (we need 50°C and below for liquid germall plus), but we also need it to be soft enough to incorporate a liquid surfactant. I used a thermometer to ensure my mash was the correct temperature, but if you don’t, when the outside of your saucepan feels about hot-tub-hot (hot tubs are typically ~40°C), mash in the preservative.
Scrape/squish the shampoo paste into your mould, and then pop your mould in the freezer for about ten minutes. After ten minutes have passed, pull it out, and lay a sheet of cling film over the shampoo. It will now be chilled (and not sticky) enough that you can use the bottom of a glass to press the bar down and get a more uniform surface.
At this point the bar should be hard enough to remove from the mould, but if it’s not, freeze it until it is. Remove it, and wait a day or two before using (if you live somewhere humid, err on the side of longer). Et voila! You just made dog shampoo.
To use: I usually pop Lottie in a bathtub or shower with a moveable shower head, put on clothes I don’t mind getting soaked, and suds her up, using the moveable shower head to rinse her clean. Our dog trainer recommends not washing a dog more than once every month or two.
As always, be aware that making substitutions will change the final product. While these swaps won’t break the recipe, you will get a different final product than I did.
- As I’ve provided this recipe in percentages as well as grams you can easily calculate it to any size using a simple spreadsheet as I’ve explained in this post. As written in grams this recipe will make 50g.
- You can use a different brittle butter (like cocoa—the amount of theobromine in white cocoa butter is extremely low so it isn’t a poisoning risk with dogs, though it should go without saying that you should not let your dog eat this shampoo bar!) instead of tucuma. I don’t recommend using anything softer, like shea or mango.
- You can use BTMS-25 instead of BTMS-50
- You can use stearic acid instead of cetyl alcohol
- If you want to mess with the surfactant blend I’d recommend reading this and this to learn more about how to do that effectively