Why human shampoo is wrong for dogs
We are often asked whether baby shampoo is not mild enough for a dog. It is not, and the reason is not mildness but the chemistry of the skin.
Different pH
Human skin is acidic, around pH 5.5. Dog skin is close to neutral, usually between 7 and 7.5, with variation by breed and age. Human shampoos are made for acidic skin. On dog skin they disrupt the acid mantle, the thin layer that protects against bacteria and fungi.
Thinner skin
A dog's epidermis is much thinner than ours. Anything that dries or irritates works faster and deeper. The coat protects, but once you have wet it and lathered it, there is no protection.
What happens in practice
After one bath with human shampoo you will see nothing. With regular use the skin gets dry, dandruff appears, the dog starts scratching, and the broken barrier opens the door to bacterial and fungal infections, which show up as smell and a greasy coat. Then the owner bathes more often and the circle closes.
What to look for in a dog shampoo
- A pH matched to dog skin (the manufacturer states it on the label)
- Mild surfactants, no SLS/SLES
- No silicones: they give a day of shine, then build up and hold dirt
- No synthetic fragrance: a dog's nose is far more sensitive than yours
- A short ingredient list you can actually read
What if I have already done it
Stop, give the skin a few weeks off from baths, and next time use a mild shampoo for sensitive skin. In most cases the skin recovers on its own.
General care information, not veterinary advice. For wounds, severe itching or hair loss, see a vet.
