Ever notice the mini lawnmowers munching away at the grass in our yards? I am not referring to those of us that own goats or the occasional cow, but to our lovable dogs. As vets, one of the questions we are constantly asked is, "My dog is eating grass, is he sick?"
A lively debate usually ensues regarding dogs and their tendency to graze. Do dogs eat grass and THEN get sick? Or, do dogs get sick and THEN eat grass? Which comes first, the chicken or the egg? Maybe they eat grass for its nutritional benefits? How about this one ó do they just enjoy it?
Whatever the reason, most people agree that it seems like an odd behaviour for cousins of wolves. Some owners are particularly upset as they feel that by eating grass, Empress (or Gaza) is betraying his or her proud carnivore heritage of stalking great woolly mammoths with our primeval ancestors over moonlit antediluvian planes. Even if you're not particularly nostalgic for the good old days of hunting and gathering, it still seems odd to see a dog eat grass. Dog chow, sure. Barbequed lamb, probably. Three-day old, flattened crapaud skin, unfortunately, yes. But grass?
Before jumping into the possible reasons for grass eating, we will briefly take a look at two general types of grass eating behaviour, the nibblers and the guzzlers. The nibblers take a few bites and nibbles, eating carefully and chewing. The guzzlers eat quickly, barely chewing.
Dogs eating greenery is not as surprising as you may think. Although our pet dogs are scientifically classified using the word 'Carnivora', dogs are not full-time carnivores (meat eaters). They can survive on a wide mix of foods that can include vegetables and grains. Dogs are omnivores, and feeding an all-meat diet for extended periods is actually risky to your pet's health. These opportunist eaters will eat whatever they fancy.
But it's still surprising that they fancy grass.
Creatures that eat grass full-time are physiologically equipped to do something useful with it. Cows (goats, sheep etc.) are called ruminants. Among many other adaptations, they have a four-compartment stomach to help deal with all the fibery material that grass is full of. This allows them to get significant nutritional benefit from eating grass.
Dog's internal plumbing (their digestive system) is hooked up much like our own. No extra help for our one simple stomach. It is not set up to digest the fibrous material in grass. Unlike cows, dogs and humans do not have the luxury of regurgitating our semi-digested food back up into our mouths to chew contemplatively on it again before swallowing it a second time. Grass goes straight into our dogs' digestive systems and, often, comes out the other end looking pretty much the same. All the exciting digestive enzymes in our pets' stomachs draw almost no nutritional value out of it.
So if dogs can't live on grass, why eat it? There are all kinds of theories, some more scientific than others. The dog spends too much time with goats. The dog has worms and is in need of a 'clean out'. The dog is predicting rain (along with Aunty Pam's arthritic knees and sometimes even the weatherman).
1. Dogs eat grass because they are lacking nutrients in their diet.
One possible explanation for this behaviour is that the dog is lacking some nutrients in its diet. This may be true in some cases where dogs are not given proper nutrients and the animal resorts to eating dirt and grass to supplement its dietary needs. Most dogs that are fed on a balanced diet do not need to supplement their diet.
2. Dogs eat grass because they feel sick.
The guzzlers who eat quickly and barely savour their grass sometimes end up throwing up their meal. Possible explanations may be that the animal is actually using the grass technique to purposely throw up, perhaps to alleviate irritation in its stomach or to remove an item stuck in its throat.
3. They just like it!
This is certainly the case with a friend's beautifully kept bull mastiffs, which are well fed on premium dog food, yet love to slowly graze, heads down in a strangely odd dog herd. The apparent love of grazing on grass rings true for many dogs as their tastes include green, leafy vegetables. My pit-bull is a lover of water-cress and caralli, strange, but true. Not surprisingly, she is a nibbler.
And the answer is...
The truth is there is no one scientifically accepted reason for dogs eating grass. Like many of life's great mysteries, there are probably many reasons. Most veterinarians agree that many dogs eat grass because they enjoy it and eating grass is not necessarily a sign of illness. In the case of the nibblers this seems highly likely.
Veterinary Advice for your Canine Lawn Mower
a. Watch the frequency of grazing and look out for other signs of illness.
Although eating grass is not necessarily a sign of illness, it is important to pay attention to how often your dog does it. Nibblers may exhibit increased grass eating particularly after rains, when grass has just begun to grow. This is fairly common and occasional vomiting occurs. There is usually no need for concern, as it can be attributed to normal canine behaviour. If your dog is a regular grass eater, you can consider supplementing her diet with dark, green leafy vegetables that are cooked, as the cooked vegetables reduce the tendency to vomit. Don't be afraid to check your Vet to come up with the best feeding plan for your furry pal, contrary to popular belief, we don't bite.
However, if your dog has recently increased his/her frequency of grass eating, with other signs of ill health such as excessive vomiting, loss of appetite, weight loss, diarrhoea and vomiting not associated with grass eating, it is important to check your friendly neighbourhood Vet. It is possible your pet is trying to compensate for gastrointestinal problems and may require veterinary intervention.
b. Watch WHERE they are grazing.
We should be mindful of where our dogs graze as manicured grasses and lawns that are treated with fertilisers, pesticides and other chemicals can be extremely toxic to our animals. A chemical free lawn/grass area should be considered for dogs. If your dog has recently eaten grass that has been treated with pesticides/fertilisers and signs of illness are seen, veterinary treatment is strongly advised.
Thanks to the
Dr Michael Diptee,
Dr John Fernandes,
Dr Akua Pottinger
and Dr Kevern Sawh