I’ve been a member of the doggie crowd forever and once, long ago in a faraway land I groomed dogs as a professional. I’ve washed more than my fair share of dogs in this lifetime and I know that shampoos, well, they are not all created equal and they do produce many differing results. I always used shampoo labeled for dogs on my Gordon Setters as I subscribed to the belief that dogs and humans have significantly different pH of skin and hair and that human shampoos were harmful to the dog’s skin and coat. Well, I just read an article that cast a new light on my old belief. So now, while I still don’t believe that all shampoos are created equal, I am thinking that the pH level is not going to be main the reason why I choose a shampoo for my dog.

Let’s start with a quick understanding of pH (potential Hydrogen), the measure of acidity or alkalinity in a solution using a scale that measures from 0 to 14. So with 7 being neutral as the pH of pure water, a measurement over 7 would be considered alkaline while under 7 would be considered acidic. Each unit of measure represents a 10 fold change so a solution with a pH of 4.0 is ten times more acidic than a solution with a pH of 5.0, and a solution of 3.0 would be ten times again, or one hundred times more acidic than the solution of 5.0. Everyone on the same page so far?

Moving on to the subject of the dog’s skin we learn that we don’t really know the pH measure. We do know that our Gordon Setter’s skin is more alkaline than human skin which measures 5.2 to 6.2 (acidic). What we don’t know for certain is the exact measure of alkalinity for the dog as various studies have produced ranges all the way from 5.5 to 9.1. So, while 7.5 is most often the cited reference number for the canine, this is simply not proven.

Small Animal Dermatology, 6^th Edition⁷ notes that, In a dynamic study of skin surface pH in dogs. ((158), the following observations were made: pH values varied at different sites on the skin and varied from day-to-day; males had significantly higher pH values than females on all sites; spayed females had significantly higher pH values at all sites than intact females; black Labrador retrievers had significantly higher pH values than yellow Labrador retrievers, and Labrador retrievers and miniature Schnauzer were significantly different from English springer spaniels and Yorkshire terriers. Clearly, skin surface pH appears to vary with site, day, coat color, sex, gonadal status, and breed. In addition, it has been reported that the skin surface pH of an excited dog can increase by greater than 1 unit within 1 minute.⁷

In anther study by the Royal Canin Research Center they found that 18 German Shepherds tested at an averaged 8.62 pH, 6 Golden Retrievers averaged 7.57 pH and 15 Labradors averaged 6.84 pH. It certainly does appear that no one pH point would be exactly proper for every dog or dog breed or dog shampoo.

On the subject of pet shampoo Barbara Bird, CMG wrote on her blog about a 2011 study she conducted in the article The pH of Pet & Human Shampoos. She gathered pH test results on over 60 pet shampoos and 45 human shampoos and what she learned was very telling. The pet shampoos had a pH range that varied from 4.5 through 8.5, the human shampoos ranged from 4.5 through 8.0 and nearly half of the total pet & human shampoos tested in the 6.0-6.5 range. Barbara wrote “…it shows how few of the pet shampoos are formulated in the range they would be expected to fall – above 6.5. Forty of the sixty pet shampoos, two-thirds of the sample tested at pH of 6.5 or less, in the acidic range along with 89% of the human shampoos. Pet MD states “Dog shampoos should be in the neutral range, around 7”. Only one-third of the pet shampoos tested in the expected range of 7.0 or higher.”  Again, very few pet shampoos on the market are falling into the pH level where we would expect to find them, most are more acidic like their human counterparts.

So, where does this leave us as we choose a shampoo for our favorite Gordon (and all the other canine friends that bless your home or family)? Here are a few things to understand.

• Your dog shampoo may or may not be alkaline as it appears there is only a 1 in 3 chance that it is above 7.0 pH. Additionally, both human and pet shampoo pH appear to measure similarly.

• The relative alkalinity of canine skin means that the dog doesn’t have an acid mantle to their skin that provides a barrier to cutaneous infection (like humans), so using a human product will not destroy that mantle as has been suggested – it can’t as the dog never possessed the mantel to begin with. Matousek, et al, at the University of Illinois, stated that “The relative alkalinity of canine skin may be partly responsible for a higher predisposition to cutaneous infections in the dog compared to other species, such as cats or humans.”

• The natural order of things will restore balance to the dog’s skin. There is no evidence supporting the theory that a shampoo that is rinsed off or a conditioner that is left in will have a prolonged effect on the pH of your dog’s skin. In one study it was found that when a vinegar spray (very acidic at 2.4 pH) was used the pH of the skin on tested dogs was reduced to under 6.0 for less than 12 hours after which the skin returned to normal.

• A shampoo on the acidic side of pH is not more irritating to your dog’s skin. If a shampoo is harsh or seems to be irritating your dog’s skin it would have to do with the cleansing ingredients or the detergent in the shampoo rather than the pH.

• An acidic shampoo leaves the hair with a more tightly closed cuticle resulting in smoother and shinier coat. A more alkaline shampoo will lift and loosen the hair cuticle allowing for deep cleansing but should be followed by a mildly acidic conditioner to close the cuticle after this cleansing.

In summary, concerns about pH level and dog shampoo are not based on science and pet shampoos seem to share a similar pH level as human shampoos. Does this mean you should throw out or stop buying those gallons of dog shampoo you may be lugging around? Oh, heavens no – I just thought you might want to know all this so you wouldn’t feel like you were mistreating your dog by irritating his skin if you used a human shampoo instead of dog shampoo.

All of this doesn’t mean that good reasons to use a dog shampoo aren’t applicable.

• Some pet shampoos are geared for a specific job or coat type and these often work very well for that purpose.

• Human shampoo is designed for more frequent use than dog shampoo as many people wash their hair daily. That means some human shampoo is milder and may not clean a really dirty dog as well as a dog shampoo. On the flip side, dogs on the show circuit that are bathed frequently may benefit from a milder human shampoo and this could be a solution for the coats that dry out from strong cleaning agents in pet shampoo.

• Many human shampoos soften hair and this might not be desirable depending on the breed you’re washing.

• There are also the pet shampoos that are formulated for whitening, de-shedding or dogs who need some serious odor control and these may not be matched by any human product.

So, what comes next? Well I think it would be very beneficial if all of you would chime in below (in the comment section) to tell us about your favorite Gordon Setter shampoo and conditioner. That is, after all, what many readers want know – what other owners are using, does it work, and why do you like it? What have you tried that you didn’t like and why? Do you have favorite human products that you use? Do you use a special shampoo for show days and another shampoo for kennel baths? Come on….it’s easy…I see many of you all typing away on Facebook so I know you can do it. Share with each other!

Happy Bath Day – Sally Gift, Mesa, AZ

Reference: The pH of Pet & Human Shampoos | BBird’s GroomBlog