Have you ever wondered why humans and dogs need different shampoos, or if our hair and their hair (fur) are the same?
We both have eyelashes and hair on our heads, and it is meant to protect us from outside elements like debris and sun damage. However our follicles and the makeup of the strands are very different than a dog's which is one of the reasons why our products and grooming routines cannot be mixed and matched.
Although a dogs hair and a humans hair are both made from keratin, a dog’s fur has a modified gene pigment, called Melacortin 1 Receptor that gives them varied colored patterns, while humans only have the two types of hair pigments, eumelanin and pheomelanin providing us with consistent coloring along the strand. Both our hair and a dog’s fur are meant to protect us from external factors and regulate body temperature, but they do it in different ways, starting with the growth and shedding cycles.
Both our hair and a dog’s fur have growth periods determined by the follicles and genetics. The hair on our heads can grow for a few years until our genetics tell it to stop, dogs have a shorter growing period than humans because the hair doesn’t need to be as long.
Fun fact: Humans generally have one hair per follicle that continues to grow, and dog fur grows in bundles within each follicle.
Both humans and dogs shed hair continuously, but dogs do a full shedding seasonally called molting so they can grow a new coat. This helps them regulate body temperature for seasonal factors like heat and cold weather.
Hair on both dogs and humans is a protective layer from outside factors like debris and UV rays. Eyelashes help protect all of our eyes from debris like sand, and the hair on our head can help regulate heat like a dog's coat traps heat in the winter. The temperature control is called thermoregulation in both humans and dogs.
There are also differences with the hair’s construction like the thickness of the medulla, the outermost layer that gives hair its body, volume, and elasticity. Animals like dogs have thicker medulla than humans, and it grows in different patterns for both the medulla and the cortex, the middle of the hair strand. Dogs' patterns are spherical, polygonal, and have round corners while humans have elliptic and rod-shaped ones.
There are some interesting variations in the actual scale-like pattern along the outer cuticle of human hair. Ours tends to be flat and overlapping like the shingles on a house giving us a softer, smoother texture, while dog hairs have more variable scale patterns that are wavy or mosaic-shaped and this determines whether they have coarse, wiry, curly, or silky hair.
Fun fact: In the study about cuticle scale patterns mentioned above, dachshunds were the only dog breed of 42 that gets split ends just like human split ends.
An interesting difference between a dogs coat and our hair is that most dogs have three types of hair, the undercoat, a guard hair that keeps growing, and a fine undercoat called wool, while humans only have two types, the fine vellus “peach fuzz” hair found on the body and the thicker terminal hairs that you can see on your head.
Fun fact: There is no such thing as a truly hypoallergenic dog. There are breeds that shed less hair but, it is the dander from the skin that people are allergic to, not the fur.
A dog’s coat and a human’s hair may serve the same purpose and be made of keratin, but they’re different enough to need dedicated grooming products like shampoos. So don’t mix and match. If you found this guide to hair health helpful, subscribe below for more just like it.
