Most Common Toxic Plants to Cats and Dogs

Overall there are 405 toxic plants to cats and dogs combined. It would be insane for me to list all of them so I am going to list the most common plants to cause toxicity - the ones they get into most frequently. I will include a picture of the plant and a list of symptoms when ingested.

Scientific Name: Aloe Vera

Family: Liliaceae

Toxicity: Cats and Dogs

Clinical Signs: Vomiting, depression, diarrhea, anorexia, tremors, change in urine color.

Scientific Name: Amaryllis sp.

Family: Amaryllidaceae

Common Names: Belladonna lily, Saint Joseph lily, Cape Belladonna, Naked Lady

Toxicity: Cats and Dogs

Clinical Signs: Vomiting, depression, diarrhea, abdominal pain, hypersalivation, anorexia, tremors

Scientific Name: Rhododendron sp.

Family: Ericaceae

Common Names: Azalea, Rhododendron, Rosebay

Toxicity: Cats, Dogs, Horses

Clinical Signs: Ingestion of a few leaves can cause serious problems. The toxic principle interferes with normal skeletal muscle, cardiac muscle and nerve function. Typically within a few hours of ingestion clinical signs begin such as digestive upset, excessive drooling, anorexia, diarrhea, depression, loss of coordination, weakness, stupor, leg paralysis, weak heart rate and recumbency for 2 or more days at which point may result in a coma and then death.

Scientific Name: Colchicum autumnale

Family: Liliaceae

Common Names: Autumn Crocus, Meadow Saffron

Toxicity: Cats, Dogs, Horses

Clinical Signs: Oral irritation, bloody vomiting, diarrhea, shock, multi-organ damage, bone-marrow suppression. 

Scientific Name: Begonia spp.

Family: Begoniaceae

Common Names: There are over 1,000 species and 10,000 hybrids

Toxicity: Cats and Dogs

Clinical Signs: Oral irritation, intense burning and irritation of mouth, tongue and lips, excessive drooling, vomiting, difficulty swallowing. The tubers are the most toxic part of the plant.

Scientific Name: Ricinus communis

Family: Euphorbiaceae

Common Names: Castor Bean Plant, Castor Oil Plant, Mole Bean Plant, African Wonder Tree

Toxicity: Cats, Dogs, Horses

Clinical Signs: Castor Beans are very toxic and cause oral irritation, burning of mouth and throat, increase in thirst, vomiting, diarrhea, kidney failure, convulsions. As little as one ounce of seeds can be lethal. Signs typically develop between 12 to 48 hours after ingestion and include loss of appetite, thirst, weakness, sweating, difficulty breathing, trembling, loss of coordination, progressive central nervous system depression, and fever. As the syndrome progresses bloody diarrhea may occur as well as convulsions and a coma can precede death.

Scientific Name: Anthemis noblilis

Family: Compositae

Common Names: Chamomile, Manzanilla, Garden Chamomile, Roman Chamomile, True Chamomile, Corn Feverfew, Barnyard Daisy, Ground-apple, Turkey-weed

Toxicity: Cats, Dogs, Horses

Clinical Signs: Contact dermatitis, anorexia, diarrhea, vomiting, allergic reactions. Long term exposure can lead to bleeding tendencies. *NOTE* Just because Chamomile calms and relaxes you...that does NOT mean that you can give it to your pets. I have heard of a few people who thought it was a great thing to give to their dogs. They thought it calmed their dogs...well yeah because you were slowly poisoning them. 

Scientific Name: Cyclamen spp

Family: Primulaceae

Common Names: Cyclamen, Sowbread

Toxicity: Cats and Dogs

Clinical Signs: Vomiting, diarrhea, salivation. The highest concentration of the toxic component is in the root of this plant. Heart rhythm murmurs can occur and fatally. 

Scientific Name: Allium sativum

Family: Liliaceae

Common Names: Garlic, Stinking Rose, Rustic Treacle, Comphor of the Poor, Nectar of the Gods, Serpet Garlic, Rocambole

Toxicity: Cats, Dogs, Horses

Clinical Signs: Breakdown of red blood cells (hemolytic anemia, Heinz body anemia), vomiting, weakness, blood in urine, panting, tachycardia (high heart rate).

Scientific Name: Cannabis sativa

Family: Cannabaceae

Common Names: Marijuana, Hashish, Indian Hemp

Toxicity: Cats, Dogs, Horses

Clinical Signs: Prolonged depression, incoordination, vomiting, sleepiness or excitation, dilated pupils, hypersalivation, low blood pressure, low body temperature, seizure, coma, death in rare cases.

Scientific Name: Nerium oleander

Family: Apocynaceae

Common Names: Oleander, Rose-Bay

Toxicity: Cats, Dogs, Horses

Clinical Signs: Poisonings of Oleander can occur from access to fallen branches and prunings. All parts of the plant contain a highly toxic cardiac glycoside and can cause diarrhea, colic, sweating, incoordination, shallow/difficult breathing, muscle tremors, recumbency, and possibly death from cardiac arrest.

Scientific Name: Epipremnum aureum

Family: Araceae

Common Names: Pothos, Golden Pothos, Devil's Ivy, Taro Vine, Ivy Arum

Toxicity: Cats and Dogs

Clinical Signs: Oral irritation, intense burning and irritation of mouth, tongue and lips, vomiting, excessive drooling, difficulty swallowing.

Scientific Name: Cycas revoluta, zamia species

Family: Cycadaceae

Common Names: Sago Palm, Coontie Palm, Cardboard Palm

Toxicity: Cats, Dogs, Horses

Clinical Signs: Vomiting, melena (black "tarry" feces associated with a gastrointestinal hemorrhage), icterus (jaundice; yellow color of skin, eyes, mucous membranes), hemorrhagic gastroenteritis, bruising, excessive thirst, coagulopathy (condition in which the blood's ability to clot is impaired), liver damage, liver failure, death.

Scientific Name: Tulipa species

Family: Liliaceae

Common Names: Tulip

Toxicity: Cats, Dogs, Horses

Clinical Signs: Highest concentration of toxin is in the bulb. If ingested vomiting, depression, diarrhea, cardiac abnormalities and hypersalivation will occur. *NOTE* If you have a dog who likes to dig and you have Tulips in your backyard be very careful and watch your dog. 

Scientific Name: Taxus sp.

Family: Taxaceae

Common Names: Yew, Japanese Yew

Toxicity: Cats, Dogs, Horses

Clinical Signs: Sudden death from cardiac failure. The early signs are: muscular tremors, dyspnea, and seizures in dogs.

These are some of the most common plants that cause high risk toxicity to cats and dogs. I didn't include many Lilies because there are so many varieties but the more dangerous, potentially fatal lilies are true lilies of the Lilium or Hermerorcallis species. Some examples of these dangerous lilies include: Asiatic hybrid, Day, Easter, Red, Japanese Show, Tiger and Stargazer. All of these are highly toxic to cats. Even a small ingestion of 2-3 petals or leaves can result in severe, acute kidney failure. Even the pollen or water from the vase! Lily of the Valley is another dangerous lily but it does not cause kidney failure, it can instead cause life threatening heart arrythmias and even death when ingested by cats and dogs. If you see your cat or dog ingesting any plant and you are not sure whether it is toxic please take your pet to the Veterinarian immediately. The sooner you take them to the Vet after they ate the plant the sooner they can be treated and have a better chance of a full recovery.