Grass, Weeds and Plants Pets Should Not Eat

May 18, 2010

By Linda Cole

Cats and dogs who wander outside during the warmer months will always find something to nibble on. Some may chew on a weed or piece of grass because it tastes good. It doesn’t harm them to eat certain plants, but some vegetation is harmful and as responsible pet owners, we need to be aware of what grows in our yards and gardens.

Pets don’t know which plants they should leave alone while on their daily patrol around their home. Eating poisonous plants is the number two toxin for cats, and ranks in the top five for dogs. Outside plants that are toxic can cause severe reactions, but for the most part, pets end up with irritations in their gastrointestinal tract or inside their mouth. If a pet eats a toxic plant, they usually get rid of most of the toxins from their system by vomiting.

Grass is perfectly fine if your pet eats some, provided it has not been chemically treated. Some dogs seem to actually crave some greenery now and then. Vets don’t really know if dogs eat the grass because they like the taste of it or if there’s something in it that’s good for them. Some think it’s a dog’s way of getting rid of an upset stomach. Whatever the reason may be, you want to avoid grass that’s been treated with toxic chemicals. If your cat or dog has access to your entire yard, be careful when putting anything on your lawn. Weed killers should also be used with your pet’s safety in mind. Make sure to keep cats or dogs off any lawn that’s been treated regardless of whether they eat grass or not. Pets who wander around a treated lawn can still pick up chemicals on their paws which can be ingested when they clean themselves.

There are more than 700 poisonous or toxic outside plants that pets need to stay away from. Most gardeners and flower lovers have heard of at least some of the plants or weeds, but those who don’t work in the garden may not be aware of what these plants are, let alone spot one on sight. However, it’s important to learn what grows in your yard, neighborhood and garden to help keep your pets safe.

Some wild growing plants, shrubs, grasses and weeds to watch out for are: Velvet Grass, Sorghum, Nightshade, Pokeweed, Smart Weeds, Baneberry, Holly, Bloodroot, Buttercup, Chockcherries, Corn Cockle, Cowbane, Cow Cockle, Jimsonweed, Mayapple, Day Lily, Morning Glory, Monkshood, Poison Hemlock and Skunk Cabbage.

Garden plants your pet shouldn’t chew on include potatoes, tomatoes, rhubarb and onions. Some garden flowers and outside plants that are toxic to pets are Crocus, Day Lilies, Tiger Lilies, Daffodils, Narcissus, Clematis, Foxglove, Morning Glory and Lily of the Valley.

If your pet does eat a toxic plant, it’s important to know what part of the plant they ate and how much they ate. On some plants, not all parts are poisonous whereas others include the entire plant. Some outside plants have toxic roots or seeds and others may have toxic leaves or stems. And some plants are more toxic than others with varying degrees of symptoms and reactions by a pet.

Symptoms to watch out for include sudden vomiting, diarrhea, heavy panting or breathing, acting like they are depressed and have no energy. Call your vet immediately if you suspect your pet has eaten something they shouldn’t have. If you know what they ate, take some of the plant, grass or shrub with you when you go to the vet. If you don’t know what it is, the vet may know, but either way it can help determine exactly what the toxin is so the vet can properly treat your pet.

Pets can’t avoid outside plants, and their curious nature can get them into trouble. It’s hard to monitor outside cats while they check out their territory, so one simple precaution would be to walk around your cat’s territory to get an idea of what kind of outside plants he could run across. That way you have an idea of what he might have eaten if he comes home with an upset tummy or is showing signs of ingesting something toxic. There are other poisons besides plants a wandering cat can find, so if you notice any signs of possible poisoning, take your pet to the vet to be on the safe side.

For more information on toxic outside plants, please check out this site. This is by no means a complete list of all 700 toxic plants, but it is a good place to start. If you have questions about a plant, talk with your vet.

Read more articles by Linda Cole

The personal opinions and/or use of trade, corporate or brand names, is for information and convenience only. Such use does not constitute an endorsement by CANIDAE® Pet Foods of any product or service. Opinions are those of the individual authors and not necessarily of CANIDAE® Pet Foods.

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  1. Is Grass-leafed Goldenrod poisness to dogs?

  2. Mercie says:

    Have23pound pup that came in from yard today had her for a week now all of a sudden she had very swollen eyes hives all over from head to paws and somewhat panting flushed her eyes with dog eye wash they half way opend she just chews on herself and lays there miserable any advice please someone help

  3. Gabrielle says:

    Thank you for this,it was needed a lot!

  4. Patty Kern says:

    Hi. I got a puppy chiwawa that is now three and a half months old. He goes out side on his own sense I have a gated yard. Today and on one other occasion he comes in and hides. He is looking all around, can’t sit still. Ears straight up ànd eyes wide open. Any idea what he could of ate too make him act like this.

    1. Michael says:

      Hi, my Chihuahua eats some plants at times in the backyard and he does the same thing. He runs and hides too. It last about 8-10 hours and scares me bad every time. It has happened three times. It’s happened today, and I cannot find an answer for it as well. It’s terrible watching him go through this, and all that it takes I guess is a few minutes and I must have missed him getting at whatever the weeds or plants it was? I normally take him out front, but there are times I cannot do it right away…..I’m making it priority. It’s scary watching him go through this, I think he might be hallucinating.

  5. Jeri L. Campbell says:

    Just put in sod grass. Is this bad for my dog to eat? Do not know if it is chemically treated. Going to check it out. Bought from Lowes.

  6. Janice Mac Duffee says:

    Need a chart showing weeds that dog should not eat.

    1. ella ballou says:

      wild flowers dogs should not eat

  7. Dee Dee says:

    Why is my neighbour’s cat obsessed , almost addicted with eating my mare’s tail weed , also known as horsetail weed , from my garden? I am trying to clear this invasive weed which is only one down from Japanese Knotweed but don’t want to poison the cat. The weed is deadly to horses and the cat has been vomiting a lot lately.I chase him off but he is almost like a heroin addict trying to sneak back to it ! I’m in desperation as is my neighbour. Many thanks.

  8. Shar says:

    Is hairy crab grass toxic to cats?I can’t find anything on it, my cat threw it up

  9. Yvonne says:

    Just got my poodle better after eating a toxic weed that grows freely in grass.

    1. my dog ate a weed this morning, he acted high, coughing, finally vomit, but was acting weird, he was trying to chew on everything. gave him water, and then a benadryl, he is better but still acting a bit strong…

  10. Mick 7 says:

    I have been pulling my poodle away from the grass recently. Now I know it's okay. A friend told me it was okay but I wanted to research and be safe.

    Thanks for the knowledge.

    Dog lover

  11. Anonymous says:

    May we next time have pictures of these poisonus plants so we can get an Idea of what they look like? We have a certain plant near my barn where the horses are and people keep saying its nightshade so may I please have pictures?