Dog licking his paw
If you lacked opposable thumbs and didn’t have access to cleansers and disinfectants, you’d probably lick yourself clean after an injury, too.

That’s what canine tongues and saliva are designed to do — in part, anyway.

Although a cat’s tongue, which is gently barbed, is especially well suited to removing debris, canine tongues run a close second for their sheer surface area.

I’ve read that canine and feline saliva (ours, too!) also contains compounds that aid in healing:

  • The enzymes lysozyme and peroxidase help destroy the cell walls of gram-positive bacteria.
  • Lactoferrin, defensins and cystatins have antibacterial qualities.
  • Thrombospondin is considered antiviral.
  • A protease inhibitor in saliva has been shown to promote wound healing.
  • Nitrate compounds break down into nitric oxide upon contact with the skin, thus inhibiting bacterial growth.
  • Growth factors, such as epidermal growth factor, can promote healing.
  • Opiorphin is a pain reliever.
All of those wonderful things in spit! Who knew?

Of course, licking isn’t always a good thing. In many cases, pets have a way of letting their tongues get the better of them. In fact, beyond brushing off big particles of dirt and imparting the occasional dose of saliva on a wound, dogs’ tongues are better off where they belong — in their mouths.

That’s because pets can get obsessed with licking to the detriment of healthy skin. There’s also a lot of bad bacteria in a pet’s mouth, so as with so many good things in life, licking is an activity best done in moderation.

Sometimes it’s hard to tell whether licking is getting out of control or just a normal canine drive, so here’s a simple rule of thumb: If there’s any evidence of a wound, hair loss or even thinning of the fur, continual licking of the area is considered excessive. It goes without saying that any of these signs also require that you seek help from a veterinarian.