Your dog may encounter and even ingest plants he comes across in his investigations of your house and yard. You need to make sure the plants within his reach are safe. Several innocent-looking and even lovely plants are dangerous to dogs. Keep these plants out of his reach.
Aroid Family (anthurium, arrowhead vine, ceriman, Chinese evergreen, cut-leaf philodendron, devils ivy, dieffenbachia, dumb cane, elephant ears, green dragon, jack-in-the-pulpit, Mexican breadfruit, nepthytis, philodendron, pothos, skunk cabbage, taro, tri-leaf wonder)
Toxicity Rating: Moderate. Dogs may sample these commonly available plants with a nibble or two, but rarely ingest enough to cause serious problems or death. Risk increases if hungry or bored dogs are housed with these plants.
Dangerous Parts of Plant: Roots, leaves and stems.
Symptoms: Mouth and throat irritation, salivation, possible stomach irritation and, rarely, diarrhea.
Plant Description: All 2,000 species of this family of plants should be treated as potentially toxic. A few, such as taro, are eaten after cooking eliminates the poison. Seven species of aroids occur naturally in wet areas. Jack-in-the-pulpit and skunk cabbage are the most common and best known of these. Dumb cane, pothos and philodendron are potted plants found in offices, restaurants and homes.
Aroids are perennials. Some are vines. The large net-veined leaves, which may have white or colored spots, are borne on leaf stalks that sheathe the stem. Most have simple leaves, but jack-in-the-pulpit has three-parted foliage. The aroid flower is a fleshy green, white or yellow spike borne inside a wraparound hood or bract (spathe). The fruits are brightly colored berries borne in tight clusters; they are not often produced by the house plant species.
Signs: The plant cells contain needlelike crystals of insoluble calcium oxalate that penetrate the skin and mouth, causing discomfort. In addition, these plants contain proteolytic enzymes that release histamine and kinins, causing swelling and an itching or burning sensation. An affected dog will shake his head and paw or rub his face and mouth. He may salivate or foam at the mouth, seek water and have visible swelling. Severely affected dogs may experience oral swelling to the point that swallowing and breathing are impaired.
Typically, dogs are not severely affected because a few bites of the plants are often a sufficient deterrent to further consumption. Occasional reports of these plants causing kidney failure in dogs have not been verified. Effects in dogs appear to be limited to the signs described above. Some of these plants have been used by humans to prevent individuals from talking by causing excessive tongue swelling; hence comes the name "dumb cane."
First Aid: For minor irritation, provide supportive care and prevent further exposure. For more severe signs, if the dog does not improve within a few minutes or if swallowing or breathing is impaired, consult a veterinarian immediately.
Prevention: Dogs should not be allowed to ingest these plants. Remove the plant from their environment.
Bulbs And Bulb-Bearing Plants Of House And Garden
Toxicity Rating: Moderate. Incidents of poisoning by these plants are rare, but special care must be taken, especially with lily of the valley.
Dangerous Parts: Bulbs, rootstock and whole plants.
Symptoms: Stomach upset, vomiting and diarrhea. For lily of the valley, additional signs may include irregular heartbeat, convulsions and death.
Signs: This group of plants is divided into two sections: lily of the valley and everything else.
Lily of the valley is far more dangerous than other plants in this group, producing a mixture of cardiac glycosides, especially convallatoxin. Toxic signs in pets after they chew on the plant include stomach upset, vomiting, irregular heartbeat, convulsions and, if sufficient quantities are consumed, death. The toxin in lily of the valley acts in a similar manner to the toxin in foxglove (digitalis).
The bulbs or corms of tulip, daffodil, jonquil, narcissus, amaryllis and iris produce primarily gastrointestinal difficulties (vomiting and diarrhea) after consumption and are not as toxic as lily of the valley. Dogs are most likely to consume the bulbs when bulbs are removed from the ground or stored prior to planting. This is not a common poisoning, but some dogs, once they find the stored bulbs, will eat them. The toxic components in these bulbs are not well identified, but may be a mixture of alkaloids that have an irritant action on the gastrointestinal tract.
First Aid: For lily of the valley, contact a veterinarian immediately. If your dog is vomiting, allow him to continue to do so, since this will remove the toxin from his gastrointestinal tract. If the vomiting is severe or persists, see the vet. In cases where your dog has eaten a large quantity, emergency treatment is imperative. For other bulbs and for iris, vomiting and diarrhea should resolve in a few hours. If the signs continue or if the dog is weak, sick, pregnant, nursing or old, a veterinarian can provide supportive care until the toxin is eliminated.
Prevention: Do not allow access to stored bulbs, and restrict access to bulb beds and newly planted bulbs. Never pen or place a dog where he can reach these plants, especially lily of the valley, since he may nibble them out of boredom.
Lupine, Texas Bluebonnet, Quaker-Bonnets
Toxicity Rating: Low to moderate in the midwestern United States, higher in the western rangelands, where lupine grows more plentifully. Different species of lupine have different toxicities. According to reports, velvet or wooly-leafed lupine is the most toxic and should never be grazed since all growth stages of this species are toxic.
Dangerous Parts: All parts, especially pods with seeds.
Symptoms: Respiratory problems, behavioral changes, trembling, coma and death.
Plant Description: Lupines are herbaceous perennials grown in gardens or found wild along roadsides, in fields and in open woods. Several stems often grow from one creeping root and reach 12 to 30 inches in height. The leaves are alternate and palmately compound with 7 to 11 spear-tip-shaped, softly hairy segments. Elongated spikes of blue, purple, white, magenta or bicolored pealike flowers appear in early summer and are followed by 1- to 2-inch, fuzzy, pealike pods.
Signs: Signs of lupine poisoning can develop within an hour or may take as long as a day. The signs are related to the nervous system and resemble the signs seen with excessive consumption of nicotine (tobacco) -- twitching, nervousness, depression, difficulty in moving and breathing, and loss of muscular control. Consumption of large quantities of lupine may cause convulsions, coma and death by respiratory paralysis.
First Aid: There is no antidote.
Prevention: Do not allow hungry dogs access to lupine, particularly when it is in the seed stage and if other food is not available. If lupines are prevalent in the yard or pasture, become familiar with the particular species, since toxicities vary.
Rhubarb, Pie Plant
Toxicity Rating: Low, unless dogs are fed the leaves intentionally.
Symptoms: Staggering, trembling, respiratory difficulties, weakness, diarrhea, increased drinking and urinating, and death.
Plant Description: This herbaceous garden perennial develops from a heavy rootstock. Its leaves grow from the base of the plant on stout, shiny, red stalks. Heart-shaped and 1 to 2 feet long by to 1 feet wide, the leaf blades have a smooth, shiny surface, darker above, with five main veins and wavy margins. Its hollow stems end in greenish-white flower clusters in late spring.
Signs: The leaves contain oxalic acid, soluble oxalates and citric acid; the stems are edible. Some oxalates are insoluble and cause local irritation, but the oxalates in rhubarb are soluble and cause systemic problems, especially in the kidneys. They can affect the electrolytes in the body, such as the balance of calcium and magnesium. Poisoning can be acute when large amounts of oxalates are consumed quickly or can be chronic if smaller amounts are eaten over a longer period of time. Low blood levels of calcium and kidney failure are commonly reported findings in soluble oxalate toxicity.
Affected dogs will appear depressed, and may stagger and tremble and be weak. Often, they will drink and urinate more as kidney function declines. Diarrhea may occur, and affected dogs may die if the electrolyte balance is extremely deranged or if the kidneys fail.
First Aid: There is no specific antidote for oxalate toxicity. If a dog is observed eating a large quantity of rhubarb or other oxalate-containing plant, call a veterinarian immediately. If the plants were ingested a day or more previously, only supportive care can be given. A veterinarian will be able to provide assistance, although death may result from electrolyte imbalance or from kidney failure.
Prevention: Do not allow dogs to ingest large amounts of oxalate. Always make sure that dogs have sufficient water, since oxalate toxicity becomes more severe if dogs go thirsty.
Toxicity Rating: Moderate. These plants grow wild in the eastern United States and cause significant problems there.
Dangerous Parts: All parts, especially leaves.
Symptoms: Stomach irritation, abdominal pain, abnormal heart rate and rhythm, convulsions, coma and death.
Plant Description: These perennial shrubs have tough, glossy, smooth-margined evergreen leaves. The large, showy flowers are in terminal clusters and have five white, pink, or red petals. Some horticultural varieties have yellow or orange petals. Common and local names for these plants include "lambkill" and "calfkill."
Signs: These plants, as well as mountain laurel, contain grayanotoxins (glycosides) that affect the gastrointestinal tract and cardiovascular system. The older name for this toxin was andromedotoxin.
For toxic signs to manifest, 0.2% by weight of green leaves must be ingested. Gastrointestinal signs develop first, generally within 6 hours of ingestion, including salivation, vomiting, abdominal pain and tremors. Disturbances in cardiac rate and rhythm may then be noted. If sufficient quantities are eaten, convulsions may occur, followed by coma and death. Not all affected dogs will die, and animals may recover without treatment, depending upon the amount ingested.
First Aid: Prevent further ingestion and provide supportive care. If clinical signs are present or if ingestion was recent, consult a veterinarian.
Prevention: Dogs should not be allowed around these plants. Keep hungry animals away from areas where they grow. Dogs may nibble or taste the leaves out of curiosity or boredom, which is not advised but seldom leads to clinical toxicosis. Honey made from the nectar of these flowers is also toxic and should not be consumed, so exercise caution when placing beehives.
Toxicity Rating: Low to moderate, depending on the situation.
Dangerous Parts: Leaves.
Symptoms: Gastrointestinal irritation, trembling, staggering, weakness, respiratory problems, heart problems, collapse, birth defects and death.
Plant Description: These tall annual plants grow from fibrous roots and produce large, hairy leaves and terminal clusters of tubular, 2-inch-long flowers on short stalks. The flowers may be white, red, lavender or yellow. Many-seeded capsules may appear in late summer. Tobacco species with colorful flowers are grown as garden ornamentals.
Signs: The toxin in tobacco is nicotine, an alkaloid with an irritating effect on the stomach, intestines and nervous system. Nicotine is related to the toxins in poison hemlock and lupine. An average cigarette can contain between 20 and 30 mg of nicotine and a cigar 120 mg. One report indicates that in a human unaccustomed to tobacco, 4 mg of nicotine can cause clinical signs and 60 mg at one time can cause death.
Dogs can easily be poisoned, either accidentally or maliciously, by tobacco products in the home. The primary route of poisoning is ingestion (eating tobacco products or drinking tobacco-tainted water), but smoke inhalation is also possible. Clinical signs nearly always are present, but only rarely is a lethal dose ingested. The initial signs of poisoning can develop within 10 to 15 minutes or may not manifest for several hours. At first, the irritating effect that tobacco has on the stomach and intestines will cause salivation, vomiting and diarrhea.
Shortly after digestive signs develop, neurologic signs appear. Initially, nicotine stimulates the nervous system, with depression of the nervous system occurring later. Early signs include nervousness, shaking, trembling, a stiff and uncoordinated gait, weakness and collapse. Cardiac abnormalities may be noted as well as respiratory difficulties, to the point of respiratory paralysis, the cause of death in lethal cases. Tobacco is also teratogenic, possibly causing birth defects if the mother is pregnant when the toxicosis occurs.
First Aid: Contact a veterinarian if any ingestion has occurred. The effects of nicotine can come on rapidly. Smaller dogs will show clinical signs more rapidly and more severely than larger ones.
Prevention: Do not allow dogs to be in contact with tobacco or tobacco products. Do not let animals drink from puddles or cups that have leached tobacco juice in them, such as when a water-filled cup has been used as an ashtray or spittoon. This water can have extremely high concentrations of nicotine. Forced ingestion or inhalation is inhumane and potentially lethal.
Dwarf Larkspur, Staggerweed, Poison Weed, Cultivated Larkspur
Toxicity Rating: Moderate. These plants are a more serious threat on western rangelands.
Dangerous Parts: All parts, especially seeds and young leaves.
Symptoms: Nervousness, loss of coordination, staggering, salivation, bloating, abnormal heart beat, respiratory difficulty, paralysis, convulsions and death.
Plant Description: These - to 4-foot-tall annual or perennial herbs bear alternate, deeply lobed (crowfoot) leaves and elongate clusters of white, blue, or purple spurred flowers in the spring. Roots grow in tuberous clusters. This weed commonly grows in open woods, along streams, in old fields, along roadsides, and on sand hills.
Signs: Larkspur is primarily a problem on western ranges, especially with cattle. Apparently, the plant is palatable, which increases the risk of clinical toxicosis. The toxicity of larkspur varies, with the highest periods of toxicity occurring during early growth and when the plant goes to seed. The toxin is a mixture of alkaloids, including ajacine and delphinine, and blocks communication between nerves and muscles. Signs appear within a few hours of ingestion.
First Aid: There is no antidote for larkspur poisoning, so treatment is supportive. A veterinarian needs to be called if the dog is bloated or if consumption was very recent as the veterinarian may be able to empty the stomach.
Prevention: Do not allow dogs to be confined in areas where there is larkspur, particularly during the early growth and seed stages. Keeping pastures mowed will greatly reduce the number of larkspur plants.
Toxicity Rating: Low to moderate. Milkweed is unpalatable and individual plants have variable toxicities. Death is not likely unless large quantities are consumed.
Dangerous Parts of the Plant: Stems, leaves and roots.
Symptoms: Gastrointestinal irritation (primarily vomiting and diarrhea), incoordination, tremors, heart problems, respiratory difficulty and death.
Plant Description: Milkweed gets its name from the thick, sticky, milky sap that oozes out of cut or torn leaves, stems and fresh pods. The usually solitary stems of milkweed grow 1 to 5 feet tall and bear opposite, sometimes whorled, sometimes fleshy leaves with entire margins. Flowers emerge in umbrellalike clusters and range in color from pink to rose-purple to orange or white. The milkweed fruit is a pod containing tufted seeds. A dozen species of milkweed grow in woods and swamps, and most commonly, in the dry soils of fields and roadsides. Dogbanes are easily confused with milkweeds. They are found in the same habitats and may cause similar poisoning.
Signs: There are several different types of milkweed with varying degrees of toxicity, with the whorled milkweeds being the most toxic. Milkweed plants are considered unpalatable and are eaten only when other foods are not available. The primary toxicants are cardiac glycosides that cause gastrointestinal, cardiac and respiratory problems and can cause death if enough are consumed. Resins, especially galitoxin, in the milky sap may also contribute to the toxicity of milkweed. Vomiting is the first sign to develop in dogs and is beneficial because further absorption of the toxin is less likely.
First Aid: There is no antidote if a dog consumes milkweed. It is important to limit further ingestion of the plants or contaminated feed. If the dog recently ate a large amount of the plant, a veterinarian should be called so that the gastrointestinal tract can be emptied and supportive care provided. Small tastes of milkweed may result in minor oral irritation, which may serve as a deterrent to further consumption. These little nibbles typically do not require treatment.
Prevention: Take care to remove milkweed to prevent consumption by your dog.
Spurges, Euphorbia (candelabra cactus, crown of thorns, cypress spurge, fields and gardens, garden plant, leafy spurge, milk bush, noxious weed, prostrate spurge, snow-on-the-mountain, tinsel tree)
Toxicity Rating: Moderate. Spurges are highly unpalatable, so they are rarely consumed in quantities sufficient to cause serious toxicity, but they are very irritating upon contact.
Dangerous Parts: All parts.
Symptoms: Gastrointestinal irritation, dermal and ocular irritation, general disability and weakness.
Plant Description: These herbaceous, sometimes succulent, or even cactuslike perennials have simple, alternate or opposite, entire or toothed leaves. The cells contain a milky, acrid sap. Their tiny flowers are clustered in small, cuplike structures resembling white-petaled flowers in some species. The fruit, three lobed and three seeded, is borne on a stalk extending from the cuplike flower structure. Spurges grow in old fields, open woods and waste areas, along roadsides, and around homes as cultivated or escaped plantings. Some are houseplants.
Signs: Spurges contain sap that is highly irritating upon contact, especially to the eyes and mouth. Upon prolonged exposure it will also irritate the skin, primarily on the legs and head. Irritation, redness, pain and swelling will result. Salivation and head shaking will ensue if the oral mucosa is affected. Blistering and open sores are possible. If a dog swallows spurge, stomach and intestinal irritation can occur, with vomiting, abdominal pain and diarrhea.
First Aid: Prevent further contact and ingestion of spurge. If a large quantity has been consumed, if an eye is affected, or if the dog cannot eat, contact a veterinarian immediately. For minor irritation, provide supportive care, since the signs are usually self-limiting and subside within 12 to 24 hours.
Prevention: Dogs should not be kept where spurges grow, or they should be supervised closely. Mow or spray to eliminate spurges, since skin irritation can occur just by contact with the plant.
Black Nightshade, Carolina Horse Nettle, Bull Nettle, Bitter Nightshade, Climbing Bittersweet
Toxicity Rating: Moderate. While the plant itself is very toxic, it is also unpalatable.
Rarely does an animal consume enough to cause a serious or lethal poisoning.
Dangerous Parts: All parts are potentially toxic, and the berries are often higher in toxicity.
Symptoms: Gastrointestinal problems and central nervous system distress. Signs can include abdominal pain, vomiting, diarrhea, loss of coordination, weakness, depression, apparent hallucinations, convulsions and possibly death.
Plant Description: Black nightshade is a low-branching annual, 1 to 2 feet tall with triangular stems that bear oval, thin-textured, alternate leaves with wavy margins. The tiny white flowers, borne in drooping clusters on lateral stalks between the leaves, resemble tomato flowers. The berry fruit is green when immature, purplish-black when ripe. Bitter nightshade resembles black nightshade except that the stems are climbing, the lower leaves are lobed at the base, the flowers are purple, and the ripe fruit is red. Horse nettles are similar but have coarser, prickly stems, larger white to purplish flowers in loose clusters, and yellow fruits that look much like small tomatoes. All three species commonly grow in open woods, old fields, waste areas and pastures, along roadsides, and around farm buildings.
Signs: Clinical signs of poisoning in the nightshade family tend to reflect gastrointestinal irritation or effects on the central nervous system or both. Green, red or black berries may poison dogs. The major toxin is solanine, an alkaloidal glycoside that, along with other glycosides and atropine, has numerous, powerful effects on the body.
Gastrointestinal signs can include vomiting, poor appetite, abdominal pain, and diarrhea that may become bloody. Central nervous system signs can include depression, respiratory difficulty, incoordination, weakness, collapse, convulsions and possibly death. It has been reported that one to ten pounds of plant material may be lethal for a horse.
Chronic toxicity has resulted from animals eating small amounts of the plants each day. These animals tend to suffer general loss of vigor, depression and diarrhea or constipation.
First Aid: If your dog eats a large amount of nightshade, contact a veterinarian immediately. In most cases dogs avoid eating this plant, so clinical cases are rare. Curious or bored dogs are most at risk. Treatment is largely symptomatic until the clinical signs wear off, which can take a day or two, sometimes longer. Death is rare in dogs, but has occurred in people who have abused these plants.
Prevention: Nearly all animals will avoid eating plants in the nightshade family unless they are extremely hungry and there is little else to eat. Dogs may be attracted to and eat the berries, so always keep them away from nightshade plants, especially if they are confined, bored or unattended.
Buckeye, Horse Chestnut
Toxicity Rating: Moderate to high.
Dangerous Parts of the Plant: Buds, nuts, leaves, bark and seedlings. Honey made from the flowers.
Symptoms: Digestive signs include excessive salivation, gastrointestinal irritation, vomiting, abdominal pain and diarrhea. Neurologic signs can include staggering, trembling, respiratory difficulty, dilated pupils, collapse and paralysis, which can proceed to coma and death.
Plant Description: The thick twigs of these medium-sized trees have glistening buds in spring and bear opposite leaves composed of five leaflets in a fingerlike arrangement. The yellowish flowers rise in large, dense, candlelike clusters at branch ends during June. The prickly fruit contains one to three nutlike seeds, glossy and leathery brown with a pale scar on each that gives the tree its name. These trees commonly grow in rich, moist woods or along riverbanks and are often planted as ornamentals.
Signs: The toxins in buckeye and horse chestnut affect the gastrointestinal tract and the nervous system. The saponic glycoside aesculin causes the toxic signs. Alkaloids may also be involved. Initially, gastrointestinal signs manifest, which can include salivation, vomiting, abdominal pain and diarrhea. If enough was ingested, neurologic signs may develop, including trembling, staggering and difficulty in breathing. Toxicity may then progress to collapse, paralysis, coma and death.
First Aid: If you see your dog eating Ohio buckeye or horse chestnut, contact a veterinarian immediately. Emergency measures can be used to remove plant material from the digestive tract. Once clinical signs are present and if it has been several hours since the plants were consumed, supportive care is all that can be provided because there is no antidote for this toxicosis.
Prevention: If dogs are outdoors near these trees, be certain that adequate food is available. If the animals are well-supervised they are not likely to consume toxic quantities from these trees.
Toxicity Rating: Moderately toxic, depending upon length of exposure.
Symptoms: Respiratory and gastrointestinal problems.
Plant Description: These familiar trees are recent additions to the list of poisonous plants. Little information is available as yet about their toxicity. Black walnuts are large (60- to 80-foot) forest trees often planted as ornamentals. The bark has characteristic broad, round ridges. The leaves are alternate and pinnately compound, 1 to 2 feet long, with 13 to 23 sharply toothed, tapered-pointed leaflets. Often there is no terminal leaflet. The fruit is a very rough nut enclosed within a clammy glandular husk, 2 to 4 inches in diameter.
Signs: Poisoning in dogs is reported occasionally when the seed hulls are consumed, causing stomach upset and diarrhea.
First Aid: Stomach upset in dogs will resolve when hulls are no longer eaten.
Prevention: Do not let dogs eat walnut hulls.
Foxtail Barley, Squirreltail Barley, Wild Barley
Toxicity Rating: Moderate. Irritation from the seedheads (awns) is likely, but serious illness and death are rare.
Dangerous Parts: Seedheads (awns).
Symptoms: Irritation of the skin, mouth, ear, nose and eye, stomach irritation and abscesses.
Plant Description: This perennial weedy grass of fields, waste places and roadsides gets its name from the long, bushy flower spikes. Each long, slender, wiry bristle bears small teeth or barbs that point backwards like tiny fishhooks.
Signs: The awns of foxtail and several other types of grasses can cause mechanical irritation to the skin, eyes, ears, nose, mouth and stomach of animals. Embedded seed heads can cause local irritation and infections or become more deeply embedded in tissues and migrate into the body. Irritation and infection often develop, necessitating removal of the plant matter. Signs depend on location of the seed and can include head shaking; sneezing; discharge from the nose or eyes; rubbing at the ears, eyes, or mouth; difficulty in chewing or swallowing; and digestive disturbance. Yellow or green foxtail, rye and millet can cause similar problems.
First Aid: For minor irritation, supportive care is all that is required. Minor irritations will resolve in about a day. Contact a veterinarian if signs of irritation do not resolve, if the eyes or ears are involved, or if the animal cannot eat. Infections and abscesses require veterinary care, and some awns may need surgical removal.
Prevention: These plants are common weeds in pastures and along roadsides. If problems occur with these plants, consider mowing to reduce awn formation or otherwise removing them. The foxtail that commonly grows in the western United States is especially problematic, and animals should be kept away from this grass.