‘Tis spring for a day already, and Joey has become a grazing dog. With the discernment of a French gourmet, he finds the tallest, tenderest blades of grass and eats them. Given that he has pointed teeth instead of flat molars that can grind side to side, this is funny to watch.
I have no clue why he does this. Some people say their dogs eat grass to throw up. Joey just eats it. Some people say it’s a spring tonic. Perhaps, but we hardly have harsh winters in California. Still others say it’s a sign of a nutritional gap. He eats about the same thing all year round, but only eats grass in the spring.
Dogs digestive systems are much different than ours.
In a human, the mouth is the first stage of digestion. We chew our food to mix it with saliva. We have flat molars and move our jaw from side to side. Dogs can’t. Taste is much more important to us. Chewing takes time. We have up to 10,000 taste buds. A dog has fewer than 2,000.
Human saliva has an enzyme — amylase — that helps break starchy foods into sugars before swallowing. Meat-eating dogs have a different enzyme — lysozyme — which kills bacteria in their food. (People use washing and cooking to help kill bacteria in food.) Because dogs don’t have amylase, they are prone to plaque and tartar on their teeth, where starches tend to stick. By contrast, humans are prone to cavities because of the sugars that amylase creates.
A dog’s mouth is designed to rip chunks of meat and bone and swallow it as quickly as possible. Their jaws are hinged to help get more food down faster. Where we have 32 teeth, a dog has 42. The gaps in their teeth along the sides of their muzzles help them grab and hold big chunks of meat for swallowing. Joey’s ancestors had to get as much food down as possible before a higher-ranking pack member or a bigger hunter came by and took the food away.
The stomach is much more important to a dog’s digestion than its mouth. A dog’s stomach has more hydrochloric acid to break down meat and bone. ( A dog’s stomach has a pH of about 1, while a human’s is between 4 and 5. Water, which is neutral, has a pH of 7.) This also allows a dog to eat raw, days-old food that would make us ill.
Food stays in a dog’s stomach longer than it does in a human. This is why dogs are generally fed once or twice a day. They feel full longer.
Once the food has been liquefied by the stomach, it moves into the small intestine, where nutrients are absorbed. The remains go on to the large intestine for further processing by bacteria and where water is absorbed. The waste then leaves the body through the rectum and anus.
Dogs actually have the shortest digestive system among mammals. It’s only about 5 percent as long as a human’s. It takes eight to nine hours for food to go from a dog’s mouth through the digestive process to elimination. For humans, it takes up to three days. This rapid processing means that any bacteria a dog has taken in won’t be in his system for long. But it also means a dog can’t full process large amounts of grain and fiber. These just pass right through the dog to elimination.
Most dog owners I know keep a sharp eye on their dogs’ eating and pooping habits. When things are good, the process runs like a good train system: they eat with appetite and poop at consistent intervals. Diarrhea, gas, constitipation or a loss of interest in food usually means something’s going on.
Infrequent or rapidly disappearing symptoms usually require little more than a short fast or a couple of days of eating bland food like rice, oatmeal, broth or boiled chicken. Anything that lasts needs a vet’s attention to check for infections, parasites, food allergies, a blockage or other problems.
Eating grass doesn’t seem to cause Joey distress. I’ll trust the wisdom of his body until it does.