Toxic Plants - Series 4 Article 4 - Plants Toxic to Cats and Dogs

-
By Merry Bogert


Caveat and general statements regarding toxicity:

1)     Not every toxic plant is discussed in these articles and, just because a plant is not discussed in the article does not mean it is not toxic.
2)     Some plants are species-specific with regards to toxicity – in other words, not all plants are toxic in the same way with all animals or people
3)     The “poisonous plant triangle” applies to any potentially toxic plant. This term means that three things are required for a particular plant to be toxic:   
 (a) the presence of some particular chemical in the plant, AND
 (b) a susceptibility or sensitivity to that chemical by the animal or person  
       ingesting or contacting the plant, AND
 (c) consumption/contact with sufficient quantity to cause a reaction.
All three must be present in order for a plant to be toxic to an individual animal or person at one particular point in time.
4)     Toxicity can range from dermatitis (a skin reaction, such as is seen with poison ivy) to gastro-intestinal issues and even death.
5)     Most accidental ingestions are unintentional and often involve children attracted to brightly colored berries, flowers, etc.

Plants Toxic to Cats and Dogs

This topic begs the question: “Why do cats and dogs eat/chew on plants?” The answer is not simple. Kittens and puppies explore their world with their mouths. Their very first exploration yields a warm mother and associated warm and soothing milk. As they grow and explore their world farther afield, some continue to taste their way through life while others seem outgrow that behavior.

We see that both cats and dogs will eat grass. Perhaps it’s to calm an upset stomach; perhaps it’s to induce vomiting; perhaps it just tastes good or is providing some needed nutrient or fiber. Nobody knows for sure. Sometimes, however, a dog or cat will be a habitual “plant eater” – either of houseplants or of plants in the garden – at which point the owner needs to pay very careful attention to what s/he is growing in the garden, and also pay attention to the plants that seem to be particularly attractive to their pet(s) so judicious removal of any potentially toxic plants may be done to prevent illness or worse.

In researching this topic, I discovered that there are a large number of plants that are potentially toxic to cats and dogs. Signs of poisoning can include increased thirst, salivation/drooling, vomiting, diarrhea, central nervous system problems, cardiac prolems, confusion, lack of coordination, and/or difficulty breathing. There may also be a delay of onset of symptoms, which can make pinpointing the cause somewhat difficult.

Lilies (Lilium spp.) are highly toxic plants to cats. Ingestion cause kidney problems that can be fatal. Dogs are less affected, but lilies should be avoided if your dog is a plant eater. All parts of lilies are toxic to some degree, but especially the bulbs.



Autumn crocus (Colchicum autumnale), daylilies (Hemerocallis), trout lilies (Erythronium spp.), and Glory-of-the snow (Chionodoxa) all contains colchicine. This potent chemical causes a burning sensation in the mouth, vomiting, diarrhea, seizures, liver and kidney damage, and even heart arrythmias.
Photo by Amanda Sletto, North Dakota State University Extension


Sweet peas (Lathyrus spp.) contain aminoproprionitrile, which can cause central nervous system and musculoskeletal problems.

Christmas/holiday plants of concern include holly (Ilex spp.), mistletoe 
(Phoradendron serotinum), Christmas rose (Helleborus niger), lilies (Lilium spp.), amaryllis (Amaryllis spp.), and poinsettia (Euphorbia pulcherrima). Of these, poinsettia is the least concerning. Ingestion does not cause life-threatening issues but can include digestive upset, drooling, vomiting, and/or oral irritation from the white sap.

Some common house plants that are toxic to dogs and cats include aloe (Aloe vera), asparagus fern (Asparagus densiflorus cv sprengeri), begonia (Begonia spp.), cycad or sago palms (Cycas spp.), jade plant (Crassula argentea), kaffir lily (Clivia), Philodendron spp., corn plant (Dracaena), dumb cane (Dieffenbachia ), English ivy (Hedera helix), fig (Ficus spp.), Gardenia, Kalanchoe spp., snake plant/mother-in-law’s tongue (Sansevieria), peace lily (Spathiphyllum), umbrella tree (Schlefflera), flamingo flower (Anthurium), and wandering Jew (Tradescantia flumininsis).

The list of problematic plants that are frequently found in the garden is a long one. It includes American bittersweet (Celastrus scandens), autumn crocus (Colchicum autumnale), andromeda (Pieris japonica), Asiatic lilies (Lilium asiatica), azalea (Rhododendron spp.), baby’s breath (Gypsophila elegans), begonia (Begonia spp.), borage (Borage officinalis), boxwood (Buxus spp.), buttercup (Ranunculus acris), English ivy (Hedera helix), caladium (Caladium hortulanum), calla lily (Zantedeschia aethiopica), cardinal flower (Lobelia cardinalis), carnation (Dianthus caryophyllus), castor bean plant (Ricinus communis), garden chamomile (Anthemis nobilis), Chinese evergreen (Aglaonema modestum), chrysanthemum (Chrysanthemum spp.), clematis/virgin’s bower (Clematis spp.), Cyclamen spp., daffodil (Narcissus spp.), dahlia (Dahlia spp.), daylily (Hemerocallis spp.), dogbane hemp (Apocynum spp.), elephant’s ears (Colocasia esculenta), fleabane/showy daisy (Erigeron speciosus), foxglove (Digitalis purpurea), “geranium” (Pelargonium spp.), gladiola (Gladiolus spp.), gloriosa lily (Gloriosa superba), hellebores (Helleborus spp.), hollies – both deciduous and evergreen (Ilex spp.), hyacinth (Hyacinthus orientalis), heavenly bamboo (Nandina domestica), hosta (Hosta plataginea and cultivars), hydrangea (Hydrangea arborescens), iris (Iris spp.), jack-in-the-pulpit (Arisaema triphyllum), Kalanchoe spp., lantana (Lantana camara), larkspur (Delphinium spp.), lavender (Lavendula angustifolia), lily of the valley (Convallaria majalis), mayapple (Podophyllum peltatum), mountain laurel (Kalmia latifolia), milkweed (Asclepias spp.), moss rose (Portulaca oleracea), oleander (Nerium oleander), peony (Paeonis officinalis), periwinkle (Vinca rosea), primrose (Primula vulgaris), privet (Ligustrum japonicum), ragwort (Senecio spp.), rhododendron (Rhododendron spp.), sorrel/shamrock plant (Oxalis spp.), St. John’s wort (Hypericum perforatum), sweet pea (Lathyrus latifolius), flowering tobacco (Nicotiana spp.), tulip (Tulipa spp.), wisteria (Wisteria spp.), yarrow (Achillea millefolium), yew (Taxus spp.), and yucca (Yucca spp.).

All parts, but especially the seeds, of stone fruits (peaches, plums, nectarines, cherries, apricots) and apples contain cyanogenic glycocides that, when digested, form cyanide poison that can cause rapid shallow breathing, bright red gums, convulsions and paralysis. Citrus fruits (oranges, lemons, limes, grapefruit) skins and leaves contain essential oils that can cause allergic skin reactions (dermatitis) and vomiting/diarrhea.

Vegetable or herb garden plantings can cause problems for dogs and cats as well. Leeks (Allium ampeloprasum), garlic (Allium sativum), onions (Allium cepa), and chives (Allium schoenoprasum) all can cause hemolytic anemia. Lemon grass (Cymbopogon citratus) contains both irritating essential oils as well as cyanogenic glycocides. Lemon verbena (Aloysia triphylla) contains essential oils, but causes only minor GI upset. Marjoram (Origanum majorana ), oregano (Origanum vulgare), and tarragon (Artemisia dracunculus) can cause gastrointestinal upset.  Tomato plants (Lycopersicon spp.) cause excessive salivation, severe GI upset, dilated pupils, general weakness, and a slowed heart rate. Ripe tomatoes cause no problems. Watercress (Nasturtium officinale – not to be confused with the flower named Nasturtium that is really Tropaeolum) can cause mild GI upset. Italian parsley (Petroselinum crispum) can cause sun-sensitive dermatitis. Rhubarb leaves (Rheum rhabarbarium) contain calcium oxalates that cause excessive salivation, weakness, tremors, and kidney failure.

In summary, from the first three sections of this series we learned that “toxicity” of one sort or another is a common defense mechanism of plants that they employ to ensure that they will live long enough to reproduce. It is incumbent on the pet owner to be aware of potentially troublesome plants and to know his/her pet and its proclivities for eating plant materials in the home and garden in order to avoid unfortunate incidents.

The American Society for the Prevention of Cruelty to Animals (ASPCA) website has an extensive listing of plants that are toxic to dogs and cats. All possible names for a toxic plant are listed, along with a photo of the plant, the causes of toxicity, and clinical signs of toxicity. The link follows: https://www.aspca.org/pet-care/animal-poison-control/toxic-and-non-toxic-plants


The Cornell Department of Animal Science maintains a useful page on poisonous plants affecting dogs. The page categorizes where plants of concern may be found such as vegetable gardens, wooded areas, flower gardens, fields, and other areas. The link for the page is  https://poisonousplants.ansci.cornell.edu/dogs/index.html

Popular posts from this blog

DON'T EAT THE BERRIES!

-
By Merry Bogert  Among the many joys of some flowering plantings in our yards are the colorful fruits that follow and provide food for wildlife. But many are toxic if consumed by humans or pets, so it pays to be aware of them in order avoid accidental poisoning. Decorative ivies such as Boston Ivy, English Ivy, and Poison Ivy all produce colorful berries that are lovely to look at but may cause stomach upset, and even be fatal if consumed. In particular, Boston Ivy berries contain calcium oxalates, needle-like crystals that cause pain and swelling in the lips, face, tongue, and skin. Ripe Virginia Creeper berries look like grapes but are extremely poisonous; they have been implicated in fatalities. American Bittersweet berries can cause stomach upset and diarrhea; invasive Asian Bittersweet’s toxicity level is not well-documented in the literature. It’s best to avoid both. Shrubs and trees with poisonous berries include: Yew (the black seed inside the fleshy red aril cau
Read more

Toxic Plants - Series 4 Article 5 - Plants Toxic to People

-
Image
By Merry Bogert Caveat and general statements regarding toxicity: 1)      Not every toxic plant is discussed in these articles. Just because a plant is not discussed in the article does not mean it is not toxic. 2)      Some plants are species-specific with regards to toxicity – in other words, not all plants are toxic in the same way with all animals or people 3)      The “poisonous plant triangle” applies to any potentially toxic plant. This term means that three things are required for a particular plant to be toxic:      (a) the presence of some particular chemical in the plant, AND   (b) a susceptibility or sensitivity to that chemical by the animal or person          ingesting or contacting the plant, AND   (c) consumption/contact with sufficient quantity to cause a reaction. All three must be present in order for a plant to be toxic to an individual animal or person at one particular point in time. 4)      Toxicity can range from dermatitis (a skin reaction, such
Read more

Ergonomics For Gardeners - Series 7 Article 3 - Applying ergonomic principles to common garden tasks

-
By Marilyn Fishman  When working close to the ground Bend from hips, not the waist . Keep the chin off the neck or chest . Keep the back straight . Work close to the body, the further away from the body the arms are, the rounder the back will be . Avoid twisting sideways: face you work area directly, for most people the muscles for lateral movements are weaker than those for forward movement . If kneeling hurts, use a cushion or knee pads. Consider trying a padded kneeler that doubles as a stool. Knee with one knee on the cushion and other bent at 90 degrees with the foot on the ground. Change position often . Avoi d working close to the ground with raised planters or beds. The height of a bed should be 24 inches for wheelchair gardeners or 30 inches for someone who wants to stand and has difficulty bending and reaching. Telescoping tools can be helpful. When carrying Avoid wheel-barrows; a two-wheeled garden cart causes less strain . Try to push rather than
Read more