Let's face it: the world of pet care is full of opinions, beliefs and ... marketing stories. One such story that has been around for years is the importance of a "correct pH level" in shampoos and grooming products for dogs and cats. But what's the real deal? Time to take a closer look at this myth.

The origins of the pH myth

Not so long ago, groomers and veterinarians simply used their own shampoo, dish soap or even green soap to clean animals. Only in the 1970s and 1980s did this change: the pet industry began to flourish, and specialty products for groomers and pets became more and more accessible.

With those new products also came a new story: human shampoos are said to have the "wrong" pH level and are therefore harmful to animals. A clever marketing move, because who wants to be unprofessional or irritate an animal? And while well-intentioned, the story doesn't quite add up.

What does science say?

Human skin has a pH of about 5.2 to 6.2 - slightly acidic, in other words. Skin care products for humans are adjusted accordingly. With dogs it is different: Their skin pH varies considerably, from 5.5 to as much as 9.1 (!), depending on breed, size and skin condition. The average pH is around 7.5, but this is based on limited research.

That means there's really no "one-size-fits-all" pH for dog shampoo. A 2011 study tested as many as 67 shampoos - both human and animal - and what did it find? There was a wide overlap in pH levels. Some dog shampoos were even more acidic or alkaline than human shampoos. The variation was even greater in animal products than in human products.

So is an acidic shampoo bad?

No, definitely not. The pH value says something about acidic or alkaline, but not directly about skin irritation. Honey, for example, has a low pH (around 3.5), but is absolutely not irritating - in fact, rather soothing. Irritation is only really seen at pH values below 3 or above 10.

Moreover, several studies show that a somewhat more acidic environment can help dogs' skin recover, precisely for skin problems. So it is not as black and white as is often thought.

But why not use human products anyway?

Good question. Here's the thing: The skin of dogs and cats is thinner than that of humans. As a result, certain substances can cause faster irritation or even damage. Also, some ingredients in human shampoos, such as zinc oxide, are downright toxic if animals ingest them. Consider, for example, what happens when your dog licks himself after shampooing

In addition, pet shampoos are often stronger in terms of cleansing (dogs do get dirtier), and are tailored to specific skin problems in animals. In the end, that does make them the better choice - but not necessarily Because of pH.

Conclusion: don't be fooled by pH

The story that an animal product must knocking in terms of pH is largely based on marketing, not hard science. The real reason to use an animal shampoo is in other things: safety, efficacy, and avoidance of harmful substances.

So: stay critical, ask questions, and choose products that are really good for the animal - not just because the label says the pH is "perfect."