First Aid for Pets That Have Eaten Plant Parts That You Think May Be Poisonous:
Luckily, most pets aren't attracted to eating plants, and when they do, they don't eat enough to cause much harm ... just a little GI upset.
On the other hand, there are exceptions, and some plants are quite deadly. I've listed them by category below, mostly with a few comments about their toxic effects.
From a treatment stand point, we treat all the different types of plant poisonings in basically the same way:
1. If you know your pet has eaten a poisonous plant within the last hour or so, the most important step is to induce vomiting to hopefully expell much of the poisonous load. You can stimulate vomiting in dogs and cats by forcing down by mouth ipecac syrup, concentrated salt water, or hydrogen peroxide. For salt water or hydrogen peroxide, use about 1/4th cup for cats and small dogs and about 1 cup for larger dogs. If not successful in 15 minutes, then repeat.
2. Give kaopectate, pepto bismol, Milk of Magnesia, or activated charcoal. The idea here is to absorb any poison left in the GI tract in hopes of preventing absorption through the intestinal wall. This will also help soothe and coat the intestinal wall from irritation.
All the above treatment recommendations are appropriate and adequate for most cases where only a small amount of poisonous substance has been eaten, but, of course, it's hard to tell how much poison was absorbed, some plants are much more toxic than others, and some patients are more susceptible than others ... especially if small in size, or older, or unhealthy to start with.
3. Get to a vet if there are neurologic signs such as twitching, inability to focus, incoordination, respiratory distress, severe weakness, etc. Your vet will continue treatment as needed with gastric lavage, medications to control seizures, ease breathing, reduce severe GI irritation. IV Fluids and other supportive care, monitoring, and observation as warranted.
Chrismas Season Plants That Can Harm Pets if Eaten:
Hyacinth, Narcissus, Daffodil Bulbs
Nausea, vomiting, diarrhea. May be fatal.
Oleander Leaves, branches Extremely poisonous. Affects the heart, produces severe digestive upset and has caused death.
Dieffenbachia (Dumb Cane), Elephant Ear
All parts of the plant can cause Intense burning and irritation of the mouth and tongue. Death can occur if base of the tongue swells enough to block the air passage of the throat.
Rosary Pea, Castor Bean Seeds
Fatal. A single Rosary Pea seed has caused death. One or two Castor Bean seeds are near the lethal dose for adults.
Spider Plants: details not known
FLOWER GARDEN PLANTS
Larkspur Young plant, seeds can cause digestive upset, nervous excitement, depression. May be fatal.
Monkshood Fleshy roots can cause digestive upset and nervous excitement.
Autumn Crocus, Star of Bethlehem Bulbs Vomiting and nervous excitement.
Lily-of-the-Valley Leaves, flowers cause irregular heart beat and pulse, usually accompanied by digestive upset and mental confusion. (especially toxic to cats)
Iris The underground stems cause severe digestive upset.
Foxglove Leaves Large amounts cause dangerously irregular heartbeat and pulse, usually digestive upset and mental confusion. May be fatal.
Bleeding Heart Foliage and roots may be poisonous in large amounts. Has proved fatal to cattle.
Philodendron, eucalyptus, azalea, ivy, amaryllis, pyracantha, boxwood, Jerusalem cherry can be poisonous
VEGETABLE GARDEN PLANTS
Rhubarb The leaf and blade are fatal. Large amounts of raw or cooked leaves can cause convulsions, coma, followed rapidly by death.
Daphne Berries Fatal. A few berries can kill a child.
Wisteria Seeds and Pods Mild to severe digestive upset. Many children are poisoned by this plant.
Golden Chain Bean-like capsules in which the seeds are suspended cause severe poisoning. Excitement, staggering, convulsions and coma. May be fatal.
Laurels, Rhododendrons, & Azaleas All parts Fatal. Produces nausea and vomiting, depression, difficult breathing, prostration and coma.
Jasmine Berries Digestive disturbance and nervous symptoms. Sometimes fatal.
Lantana Camara (Red Sage) Green berries Fatal. Affects lungs, kidneys, heart and nervous system. Grows in the southern U.S. and in moderate climates.
Yew Berries and Foliage Foliage more toxic than berries. Death is usually sudden without warning symptoms.
TREES AND SHRUBS
Wild and cultivated cherries twigs and foliage: Contains a compound that releases cyanide when eaten. Gasping, excitement and prostration are common symptoms. Often fatal
Castor oil bush (dogs love the seeds)
Cherry laurel (common hedging plant)
Laburnum (and related species)
Philodendron (popular ornamental house plant)
Oaks Foliage and acorns affects kidneys gradually. Symptoms appear only after several days or weeks. Takes a large amount for poisoning.
Elderberry All parts, especially roots are toxic. Children have been poisoned by using pieces of the pithy stems for blowguns. Nausea and digestive upset.
Black Locust Bark, sprouts, and foliage are toxic. Children have suffered nausea, weakness and depression after chewing the bark and seeds.
Walnuts....especially Black Walnuts and Black Walnut Wood
If you're a wood worker you should know that walnut wood can be quite toxic to pets.
Horses are also at risk if the shavings are used in the stall. And walnuts left on the ground are potentially toxic...especially if starting to mold or rot
Moldy walnut poisoning occurs after a rain and walnuts become infected with mold that produces toxins.
If ingested by your pup, the animal can become very ill and possibly die. Symptoms include vomiting, drooling, and neural signs such as trembles, seizure, and in coordination. Keep walnuts picked up and do what ever is necessary to keep your dog(s) from chewing on them.
PLANTS IN WOODED AREAS
Jack-in-the-Pulpit All parts, especially roots Like Dumb Cane, contains small needle-like crystals of calcium oxalate that cause intense irritation and burning of the mouth and tongue.
Moonseed Berries The berries are a purple color resembling wild grapes. May be fatal.
Mayapple Apple The foliage and roots contains at least 16 active toxic principles, primarily in the roots. Children often eat the apple with no ill effects, but several apples may cause diarrhea.
Mistletoe Berries Fatal. Both children and adults have died from eating the berries.
PLANTS IN SWAMP OR MOIST AREAS
Water Hemlock All parts Fatal. Violent and painful convulsions. A number of people have died from hemlock.
PLANTS IN FIELDS
Buttercups All parts are an irritant. Juices may severely injure the digestive system.
Nightshade All parts, especially the unripened berry Intense digestive disturbance and nervous symptoms. Often fatal.
Poison Hemlock All parts can be fatal. Resembles a large wild carrot.
Jimson Weed (Thorn Apple) All parts are toxic. Abnormal thirst, distorted sight, delirium, incoherence and coma. Common cause of poisoning. Has proved fatal.