Eating Grass and other plants in Dogs

Eating Grass

Question: Why does my dog eat grass? Why does he try to eat grass only in a few spots... my well fertilized, well watered lawn? Does it have something to do with the same needs that humans have for vegetabke material?


Answer: Frank-

Eating grass seems to be a normal behavior for dogs even though we tend to think that their diet should consist of other things. There have been a number of studies done trying to link grass eating with illness, vitamin or mineral deficiencies, lack of roughage in the diet and other things --- all without producing a strong correlation to any particular problem.

It is interesting that your dogs are choosing particular spots. If the grass is different in this spot it may just taste better. I know of several dogs in my practice who eat grass that other dogs have urinated on. If it is possible that this is happening it might explain the preference for these spots, since many dogs urinate in the same spot frequently.

I wish that I did have an answer for this question, as it is a frequent one in my practice.

Mike Richards, DVM 12/7/2001

What value is eating grass to dogs

Question: Dr. Richards,

Is there nutritive or palliative value in certain grasses? If so, would you know which grasses? And what is in those grasses that will make dogs or cats eat them?

Tony A.

Answer: Tony-

I am sure that there are nutrients in grasses but I don't think that there are ones that are essential to dog or cat health that are not found in their usual diet. I do not know of any therapeutic value to grass ingestion. That doesn't necessarily mean that there isn't some value I'm not aware of, though.

I think that some dogs and cats like the taste or texture of grass. Wild dogs and cats probably ingest grass as part of their diet when they eat herbivores who have ingested grass so it may be a flavor they have a genetic predisposition to like, although that is just conjecture on my part.

If there ever is a proven strong link to any diagnostic, therapeutic or essential nutrient value for grass that shows up in the veterinary literature I know that it would resolve a lot of questions that I get and will show up on line quickly.

Mike Richards, DVM 9/18/2001

Eating grass

Question: we have 5 goldens, all of them eat grass. is this a bad thing ? we hear various opninions.

Alick & Moira

Answer: Alick and Moira

I do not consider dogs eating grass to be a bad thing. I do not know what nutritional benefits there might be in eating grass but I have only seen two serious problems from eating grass and they both were cases in which a pet (one dog and one cat) ate grass and subsequently vomited it up, at least we think that was what happened. In each case a blade of grass ended up in the nasal passages and led to a strong foreign body reaction and infection. The positioning of the grass in the nasal passages is what I am basing the theory of it being vomited into the nasal passages rather than inhaled into them on. This is obviously not a common problem.

Whether or not eating grass indicates that there is some underlying problem is a much harder question to answer. If it does, no one that I am aware of has been able to make a consistently reliable connection between the grass eating and a particular medical condition. There do seem to be some dogs and cats that eat grass when they feel nauseous or have gastro-intestinal problems but there are so many dogs and cats that eat grass with no problems at all that it is hard to make a strong connection between grass eating and gastrointestinal discomfort in pets. It is even harder to make a case for nutritional deficiencies or other things that people have worried about based on this behavior.

My personal opinion is that most dogs and cats that eat grass do so because they get some satisfaction from it and that it isn't an indication of a problem of any kind most of the time.

Mike Richards, DVM 5/12/2001

Grass eating in Westie

Question: Dr. Richards:

I am a new subscriber to your site and very much appreciate all the information you had on dogs with diabetes. I have a 6 year old Westie who was diagnosed this past May and gets one insulin shot every morning. He is doing so good.

My question is about my other Westie who is 10 years old. Lately, and quite frequent has had stomach problems which makes him eat grass. He doesn't have an apetite for his food until he has eaten grass and thrown it up. His stomach noises keeps him up (and us) all night. Is there something that I can give him to calm his stomach. Is there something missing from his diet? Otherwise, he is a very healthy dog. Please help. Sleepless in Birmingham.


Answer: Ada-

Grass eating is a pretty non-specific sign. Dogs that have digestive tract disturbances eat grass sometimes, some dogs eat grass for no reason at all and there are probably other reasons for this behavior. Gastro-intestinal problems may include ulcers, inflammatory bowel disorders, insufficient digestive enzymes, mast cell tumors, intestinal blockages and other problems. There are no known vitamin or mineral deficiencies that consistently lead to grass eating, so there is not much reason to worry about this possibility. Some dogs do seem to eat less grass if they are given other green foods, such as green beans, though.

If you are pretty sure that gas is the major problem, it doesn't hurt to try a product containing simethecone, such as DiGel (tm) or Curtail (tm), to see if they will help. However, if there are any signs of a more serious problem, such as weight loss, vomiting or diarrhea then it would be best to discuss this with your vet. There is a good chance that at least some lab work will be necessary to discover the cause of this problem, so it may take some patience to work through the necessary diagnostic process. It could make your nights easier to find out what is going on, as well as possibly making your Westie feel better.

Mike Richards, DVM 10/17/2000

Grass eating in Springer

Q: Dear Dr. Mike: My 5 month old English Springer spaniel has been recently eating grass. Is this some sort of deficiency in her diet? Also, I don't know if these two things are related, but I have also noticed that her nose is dry and warm, not cool and wet like it should be. I live in Texas, so it is very hot here, but she is kept indoors. If you can tell me if there is a major problem, I would appreciate it. Thank You, Amanda

A: Amanda- A lot of conditions have been linked with eating grass but there doesn't seem to be a strong correlation with any of them. It is not a bad idea when this behavior occurs suddenly to check for intestinal parasites (do a fecal exam) and have a general physical exam done to be sure that there isn't a contributing disease. Most of the time there won't be an identifiable cause for grass eating, though. I honestly think that many dogs just like grass for some reason.

It is not unusual for dogs to have a warm, dry nose, even if they usually have a moist cold nose. To the best of my knowledge there is no significance to this finding alone, unless the nose is so dry that the skin is cracked or sore looking.

While it sounds to me like your springer is normal, it wouldn't hurt to check with your vet, too.

Mike Richards, DVM

Eating grass

Q: Dear Doc, My eight-year old dog has been eating a lot of grass for the past day and a half. I'm ready to take him to the vet, but I thought I'd ask you first. Three days ago a friend gave him a couple steak ribs to chew on. I think this may be the root of the problem; or maybe he ate something he shouldn't have (which is rare for him). I have noticed his stomach making weird noises, and some intermittent grass chomping over the past two months (maybe fours days out of a each month). I leave my dog with another friend when I go to work. Perhaps this person is feeding him things he shouldn't have. I saw the article in your site about food with too much sodium in it. Could this be the reason for the grass chewing? You have a terrific service. Thank you for your help.

A: R-

Unfortunately, grass chewing is just too non-specific a sign to say much at all about it. I think that some dogs do eat grass in an effort to calm an upset stomach, which could have occurred with ingestion of the steak bones. If odd signs are still present, I think it would be best to consult with your vet about them.

Hope all is well now.

Mike Richards, DVM

MSG and or Vitamin C for dog that eats grass

Q: Dear Dr. Mike, I have a 4 yr old female rottweiler I adopted from a shelter about a year ago. I've owned dogs all my life and have never known one to eat as much grass as this one. I posted to a rottweiler discussion group about it and got lots of feedback--seems others have had the same experience (though I doubt it's exclusive to rotts). Anyway, people have recommended feeding fruits and vegetables ( I tried apples for awhile but she lost interest; her picky eating is another of my concerns) and MSM--a dietary sulfur? Some recommended MSM with vitamin C, and others recommended just vitamin C. One person who swears by MSM says it also keeps her cat (who frequently vomits right after he eats--and guess what, so does mine!) from vomiting. My dog does not vomit, however, before or after eating food or grass, and she seems to be digesting fine; sometimes her bowel movements are softer than they probably should be, I think, but I always thought some of that was normal. My question is: What do you think about MSM or vitamin C for the dog or the cat? If you think it's worthwile, how would I determine the dosage for a 90 lb. dog and a 10 lb. cat? In what form? TIA for any advice on this matter. T

A: T

I can't see much harm in administering MSM but there are no proven benefits that I am aware of, either. That was still the FDA's position on MSM in a recent statement, too. I don't see any harm in trying it, though.

Vitamin C use in dogs and cats is extremely hard to figure out. It is generally agreed that dogs and cats can manufacture Vitamin C and do not have a demonstratable need for it as a dietary requirement. Beyond that everything is controversial. There are many vets who do recommend Vitamin C supplementation on the theory that it is beneficial and that dogs and cats may have less problems with arthritis, more disease resistance, less cancer -- pretty much the benefits seen in people. In addition, some vets feel that making the Vitamin C enough for maintenance may not mean a dog or cat can produce enough for these other benefits.

Dose is also controversial. There are references that begin to cite harmful effects at doses over 500mg/day and there are references in which people tout the benefits of doses much higher than that. Vitamin C is a water soluble vitamin and unlikely to be much of a problem except in massive doses but it seems reasonable to stick to the 500mg/day region to me. In young, fast growing breeds it seems more important to stick to the lower dosage as there is some evidence that excessive Vitamin C may contribute to hypertrophic osteodystrophy, although even that is controversial. The dose is not weight dependent, so as far as I know it is the same for dogs as for cats.

Hope this doesn't just make you more confused. The summary is that both MSM and Vitamin C are probably pretty safe and that there isn't much evidence I am aware of that proves either one works for this condition.

Mike Richards, DVM 4/27/99


Michael Richards, D.V.M. co-owns a small animal general veterinary practice in rural tidewater Virginia. Dr. Richards graduated from Iowa State University's College of Veterinary Medicine in 1979, and has been in private practice ever since. Dr. Richards has been the director of the PetCare Forum...