We have often seen cats licking themselves, which we often associate with grooming. The same cannot be said for dogs though who seem to lick themselves at frequent intervals for several reasons apart from grooming. Here are some of the more basic reasons as to why dogs usually lick themselves.
The mother would usually groom her pup several times a day. In addition to cleaning their bodies, this particular action would be extremely soothing for the pup. Many dogs tend to carry this habit forward when they grow up, and lick themselves if they feel stressed out or need comfort. This would enable them to calm down and feel relaxed.
De-sanitize and disinfect
Not many know this but the saliva is considered to be a very effective disinfectant that can reduce the risk of infections in a body. A dog would most probably lick the site of a wound or allergy to disinfect and sanitize it in order to prevent secondary infections from setting in.
Licking would also enable a dog to remove dirt, dust, debris and even unhealthy tissue from wounds. And in some cases, a dog would lick itself to get relief from the persistent itching sensation that accompanies a wound.
Dogs which are allergic to dust, dirt, mold, pollen and other irritants usually lick themselves to get relief from the itching sensation caused by these allergens. In certain cases, they would also scratch or bite themselves excessively to get rid of the sensation.
A female dog would usually start licking her vaginal area right before the breeding season. This is an indication that she is ready to mate. She would actually lick the area to keep it clean and hygienic during this period. In certain cases, a foul smelling, bloody discharge can be seen around the vaginal area during this period.
A female dog (unsprayed) could also be suffering from a vaginal infection called pyometra wherein she would repeatedly lick the vaginal area to clean it. One suffering from a vaginal infection would also urinate frequently, drink lots of water and would experience a foul smelling white vaginal discharge.