Why does my old dog's breath smell so bad?
A urine odor to your dog's breath is a warning sign of kidney disease, and warrants a visit to your veterinarian.
Kidney disease is serious and could be a symptom of a larger medical problem.
Many believe it's instinctual behavior, harkening back to the days when your dog's wild ancestors would mask their scent to help them sneak up on their prey.
Wolves, for example, have been observed rolling in animal carcasses or the droppings of plant-eating animals, to cover up their own smell during the hunt.
Dogs also lick because they like the taste of an owner's salty skin and out of habit.
Mostly, with domestic Dogs, it's a sign of affection.
Licking releases pleasurable endorphins which gives Dogs a feeling of comfort and pleasure — like the feeling people get when they are biting their nails — it relieves stress.
And grass-eating doesn't usually lead to throwing up - less than 25% of dogs that eat grass vomit regularly after grazing.
Other suggested reasons why your dog might be eating grass include improving digestion, treating intestinal worms, or fulfilling some unmet nutritional need, including the need for fiber.