Poisoning

Poisoning
A poison is any substance harmful to the body. Dogs, being curious by nature,
tend to explore out-of-the-way places such as wood piles, weed thickets, and
storage areas. These environs put them into contact with insects, dead animals, toxic plants, and poison baits. It also means the exact cause of poisoning
will not be known in many cases.
Intentional, malicious poisoning is a factor to consider whenever a dog is
found dead without apparent cause. However, several studies have shown that
most cases of sudden death are caused by accidents and natural events. Malicious
poisoning does occur, but it is far less common than accidental poisoning.
General recommendations for the treatment of poisoning are discussed in
the next section. In the sections that follow, specific poisons are discussed in
the order in which they are most frequently seen by veterinarians.
EMERGENCIES • 23
GENERAL TREATMENT OF POISONING
If your dog ingests an unknown substance, it is important to determine
whether that substance is a poison. Most products have labels that list their
ingredients, but if the label doesn’t tell you the composition and toxicity of the
product, call the ASPCA Animal Poison Control Center at (888) 426-4435
for specific information. The Poison Control Center has a staff of licensed veterinarians and board-certified toxicologists on call 24 hours a day, every day of
the year. You will be charged a consultation fee of $50 per case, which can be
charged to most major credit cards. There is no charge for follow-up calls in
critical cases. At your request, they will also contact your veterinarian. You can
also log onto www.aspca.org and click on “Animal Poison Control Center” for
more information, including a list of toxic and nontoxic plants.
Other poison control hotlines include the Angell Animal Poison Control
Hotline, operated by Angell Animal Medical Centers and the Massachusetts
SPCA (877-226-4355, www.smspca.org) and the Animal Poison Hotline,
operated by the North Shore Animal League and PROSAR International
Animal Poison Center at (888) 232-8870.
In some cases, you can call the emergency room at your local hospital, which
may be able to give you information about how to treat the poison. Specific antidotes are available for some poisons, but they cannot be administered unless the
poison is known, or at least suspected by the circumstances. Some product labels
have phone numbers you can call for safety information about their products.
When signs of poisoning develop, the most important consideration is to
get your dog to the nearest emergency veterinary facility at once. If possible,
find the poison and bring the container with you. This provides the emergency personnel with an immediate diagnosis and expedites treatment.
If the dog has ingested the substance recently, residual poison is often present in his stomach. An initial and most important step is to rid the dog’s
stomach of any remaining poison. The most effective way to empty the stomach is to pass a stomach tube, remove as much of the stomach contents as possible, and then wash the stomach out with large volumes of water. This must
be done by your veterinarian.
In many cases it is preferable to induce vomiting at the scene rather than
proceed directly to the veterinary hospital. For example, if you see the dog
swallow the poisonous substance, it is obviously best to make the dog vomit it
right back up. Similarly, if the poison was ingested within two hours but it will
take 30 minutes or longer to get to a veterinary facility, it is frequently advisable to induce vomiting at home. However:
DO NOT induce vomiting
• If the dog has already vomited
• If the dog is in a stupor, breathing with difficulty, or shows any sign of
neurologic involvement
24 • DOG OWNER’S HOME VETERINARY HANDBOOK
• If the dog is unconscious or convulsing
• If the dog has swallowed an acid, alkali, cleaning solution, household
chemical, or petroleum product
• If the dog has swallowed a sharp object that could lodge in the esophagus or perforate the stomach
• If the label on the product says, “Do not induce vomiting.”
How to Induce Vomiting and Prevent Poison Absorption
Induce vomiting by giving the dog hydrogen peroxide. A 3 percent solution is
most effective. Give 1 teaspoon (5 ml) per 10 pounds (4.5 kg) body weight of
the dog. Repeat every 15 to 20 minutes, up to three times, until the dog vomits. Walking the dog after giving each dose may help to stimulate vomiting.
Syrup of ipecac has been recommended in the past, but hydrogen peroxide
is a better choice for dogs. Syrup of ipecac (not ipecac fluid extract, which is
14 times stronger) is only 50 percent effective and can be dangerous to dogs.
It should not be used to induce vomiting unless specifically advised by your veterinarian. The dose is .5 to 1 ml per pound (.45 kg) of body weight, with a maximum
dose of 15 ml (1 tablespoon). Repeat in 20 minutes (once only) if the dog
does not vomit.
Once the poison has been cleared from the dog’s stomach, give him activated charcoal to bind any remaining poison and prevent further absorption.
The most effective and easily administered home oral charcoal product is
compressed activated charcoal, which comes in 5-gram tablets (recommended for the Home Emergency Medical Kit). The dose is one tablet per 10
pounds (4.5 kg) of body weight. Products that come in a liquid or as a powder
made into a slurry are extremely difficult to administer at home with a syringe
or medicine bottle. The slurry is dense and gooey, and few dogs will swallow it
voluntarily. These products are best administered by stomach tube. This is
routinely done by your veterinarian after flushing out the stomach.
If activated charcoal is not available, coat the intestines with milk and egg
whites using 1⁄4 cup (60 ml) egg whites and 1⁄4 cup milk per 10 pounds (4.5 kg)
of body weight. Administer into the dog’s cheek pouch using a plastic syringe
(see How to Give Medications, page 567).
Intensive care in a veterinary hospital improves the survival rate for dogs
who have been poisoned. Intravenous fluids support circulation, treat shock,
and protect the kidneys. A large urine output assists in eliminating the poison. Corticosteroids may be given for their anti-inflammatory effects. A dog
in a coma may benefit from tracheal intubation and artificial ventilation during the acute phase of respiratory depression.
EMERGENCIES • 25
Seizures
Seizures caused by poisons are associated with prolonged periods of hypoxia
and the potential for brain damage. Continuous or recurrent seizures are controlled with intravenous diazepam (Valium) or barbiturates, which must be
administered by a veterinarian.
Note that seizures caused by strychnine and other central nervous system
poisons may be mistaken for epilepsy. This could be a problem, because immediate veterinary attention is needed in cases of poisoning, but not for most
epileptic seizures. Seizures caused by poisoning usually are continuous or recur
within minutes. Between seizures the dog may exhibit tremors, lack of coordination, weakness, abdominal pain, and diarrhea. In contrast, most epileptic
seizures are brief, seldom lasting more than two minutes, and are followed by
a quiet period in which the dog appears dazed but otherwise normal. If your
dog is having a seizure, see the treatment section under Epilepsy, page 369.
CONTACT POISONS
If your dog’s coat or skin comes in contact with a poisonous substance or toxic
chemical, flush the site with large amounts of water for 30 minutes. Wear rubber or plastic gloves and give the dog a complete bath in lukewarm water.
Even if the substance is not irritating to the skin, it must be removed.
Otherwise the dog may lick it off and swallow it.
DRUG POISONS
Unintentional overdose with veterinary medications and accidental ingestion
of both human and veterinary pills are the most common causes of poisoning
in pets. Veterinary products, in particular, are often flavored to encourage a
dog to take them, and will be eagerly consumed if they are discovered.
Many people give over-the-counter medications to their dogs without veterinary approval, to treat a variety of symptoms; they believe that what works
for people works for dogs. Unfortunately, this is not correct. Drugs given to
dogs in human dosages are often toxic—and some human drugs cannot be
given to dogs in any amount.
Common pain relievers such as ibuprofen (Advil) and acetaminophen
(Tylenol) are a particular problem. Dogs and cats do not have the necessary
enzymes to detoxify and eliminate these drugs. This can lead to the accumulation of dangerous substances in the animal that are left behind when the
drugs are metabolized. As few as two Tylenol tablets can produce severe organ
damage in a medium-size dog. Symptoms develop quickly and include abdominal pain, salivation, vomiting, and weakness.
26 • DOG OWNER’S HOME VETERINARY HANDBOOK
Other human drugs that produce a variety of toxic effects and are commonly involved in accidental poisonings include antihistamines, sleeping
pills, diet pills, heart pill, blood pressure pills, and vitamins.
Treatment: If you suspect your pet has swallowed any drug, immediately
induce vomiting. Call your veterinarian for further instructions. A specific
antidote may be available for the drug in question.
Prevention: Accidental poisoning can be prevented by always consulting
your veterinarian before administering any medication. Follow instructions
exactly for frequency and dosage. Store all drugs in a secure place to prevent
inadvertent consumption by pets and children. Never assume that a human
drug is safe for pets!
RODENT POISONS
Common rat and mouse poisons include anticoagulants and hypercalcemic
agents. Both can be deadly if your dog ingests them.
Anticoagulants
Anticoagulant rat and mouse poisons are the most commonly used household
poisons. These products account for a large number of accidental poisonings in
dogs and cats. Anticoagulants block the synthesis of vitamin K, essential for
normal blood clotting. Vitamin K deficiency results in spontaneous bleeding.
Observable signs of poisoning do not occur until several days after exposure. The dog may become weak and pale from blood loss, have nose bleeds,
vomit blood, have rectal bleeding, develop hematomas and bruises beneath
the skin, or have hemorrhages beneath the gums. The dog may be found dead
from bleeding into the chest or abdomen.
There are two generations of anticoagulants, both in current use. The first
generation are cumulative poisons that require multiple feedings over several
days to kill the rodent. These poisons contain the anticoagulants warfarin and
hydroxycoumadin.
Second-generation anticoagulants contain bromadiolone and brodifacoum, poisons that are 50 to 200 times more toxic than warfarin and hydroxycoumadin. These products are more dangerous to pets and are capable of
killing rodents after a single feeding. It is even possible for a small dog to be
poisoned by eating a dead rodent with residual poison in its stomach.
Closely related to the second-generation anticoagulants are the longacting anticoagulants of the indanedione class (pindone, diphacinone,
diphenadione, and chlorphacinone). These products are extremely toxic.
Treatment: Seek immediate veterinary help. If at all possible, bring in the
product container so the veterinarian can identify the poison. This is important because treatment depends on whether the poison was a first- or secondEMERGENCIES • 27
generation anticoagulant. With observed or suspected recent ingestion,
induce vomiting (see page 25).
Treatment of spontaneous bleeding caused by all anticoagulants involves
administering fresh whole blood or frozen plasma in amounts determined by the
rate and volume of blood loss. Vitamin K
l is a specific antidote. It is given by
subcutaneous injection and repeated subcutaneously or orally as necessary until
clotting time returns to normal. With first-generation anticoagulants, this often
occurs within a week. With long-acting anticoagulants, treatment takes up to a
month because of the length of time the poison remains in the dog’s system.
Hypercalcemic Agents
Hypercalcemic agents are poisons that contain vitamin D (cholecalciferol) as
their effective agent. Cholecalciferol poisons work by raising the calcium content in blood serum to toxic levels, eventually producing cardiac arrhythmias
and death. They are becoming increasingly popular because rodents do not
develop resistance to them and, with the rare exception of a puppy or small
dog, dogs who eat poisoned rodents will not develop toxicity. In virtually all
cases, the dog must eat the poison itself to become ill.
In dogs, signs of hypercalcemia appear 18 to 36 hours after ingesting the
poison. They include thirst and frequent urination, vomiting, generalized
weakness, muscle twitching, seizures, and, finally, death. Among survivors,
the effects of an elevated serum calcium may persist for weeks.
Treatment: If you suspect your dog has ingested one of these poisons
within the past four hours, induce vomiting (see page 25) and notify your veterinarian. Veterinary treatment involves correcting the fluid and electrolyte
imbalances and lowering calcium levels using diuretics, prednisone, oral phosphorus binders, and a low-calcium prescription diet. Calcitonin is a specific
antidote, but it is difficult to obtain and has only short-term effects.
ANTIFREEZE
Poisoning by antifreeze that contains ethylene glycol is one of the most common small animal toxicities. Antifreeze has a sweet taste that appeals to dogs.
Exposure typically occurs when antifreeze drips from the car radiator and is
lapped up by the pet. Dogs may also drink from the toilet bowl in vacation
homes that have been winterized by pouring antifreeze into the bowl.
Less than 3 ounces (88 ml) is enough to poison a medium-size dog. The
poison primarily affects the brain and the kidneys. Signs of toxicity are doserelated, and occur within 30 minutes to 12 hours after ingestion. They
include depression, vomiting, an uncoordinated “drunken” gait, and seizures.
Coma and death can occur in a matter of hours. Dogs who recover from acute
intoxication frequently develop kidney failure one to three days later. Death
is common.
28 • DOG OWNER’S HOME VETERINARY HANDBOOK
Treatment: If you see or suspect that your pet has ingested even a small
amount of antifreeze, immediately induce vomiting (see page 25) and take
your dog to the veterinarian. If treatment will be delayed, administer activated charcoal (see page 25) to prevent further absorption of ethylene glycol.
A specific antidote (4-methylpyrazole) is available to treat poisoning. It is
most effective when given shortly after ingestion and early in the course of
treatment. Intensive care in an animal hospital may prevent kidney failure.
Prevention: This common cause of pet and child poisoning can be prevented by keeping all antifreeze containers tightly closed and properly stored,
preventing spills, and properly disposing of used antifreeze. A new generation
of antifreeze products contain propylene glycol rather than ethylene glycol.
The U.S. Food and Drug Administration has labeled propylene glycol as
“generally recognized as safe,” which means it can be added to foods.
However, that is in small amounts. Ingesting propylene glycol antifreeze can
cause lack of coordination and, possibly, seizures, but is unlikely to be fatal.
POISON BAITS
Animal baits containing strychnine, sodium fluoroacetate, phosphorus, zinc
phosphide, and metaldehyde are used in rural areas to control gophers, coyotes, and other predators. They are also used in stables and barns to eliminate
rodents. These baits are highly palatable and therefore may be accidentally
ingested by a dog. Many are extremely toxic and kill in a matter of minutes.
Fortunately, they are being used less frequently because of livestock losses,
concerns about persistence in the environment, and the potential to poison
pets and children.
Strychnine
Strychnine is used as a rat, gopher, mole, and coyote poison. In concentrations greater than 0.5 percent its use is restricted to certified exterminators. It
is available to the public in concentrations of 0.3 percent or less. With better
regulation and the use of lower concentrations, strychnine is becoming a less
common cause of accidental poisoning.
Signs of strychnine poisoning appear within two hours of ingestion. They
include agitation, excitability, and apprehension, followed rather quickly by
intensely painful convulsions with rigid extension of all four limbs. Seizures
last about 60 seconds, during which time the dog throws his head back, stops
breathing, and turns blue. The slightest stimulation, even touching the dog or
clapping the hands, can trigger a seizure. This type of seizure response is typical only of strychnine.
Other signs of poisoning include tremors, champing, drooling, uncoordinated muscle spasms, collapse, and paddling of the legs.
EMERGENCIES • 29
Treatment: Induce vomiting (see page 25) immediately after ingestion. But
do not induce vomiting if the dog is unresponsive, convulsing, or having difficulty breathing. Cover the dog with a coat or blanket and proceed as quickly as
possible to the nearest veterinary clinic. Further treatment involves administering intravenous diazepam (Valium) or barbiturates to control seizures. The dog
is placed in a dark, quiet room and disturbed as little as possible.
Sodium Fluoroacetate
Sodium fluoroacetate (compound 1080/1081), a very potent rat and gopher
poison, is restricted to licensed pest control operators and is used infrequently
in the United States. Dogs and cats have been poisoned by eating a dead
rodent that has ingested the poison. The onset is sudden and begins with
vomiting, followed by agitation, staggering, convulsions, and collapse.
Treatment: Treatment is similar to that described for strychnine poisoning
(on this page).
Metaldehyde
This poison, often combined with arsenic, is found in rat, snail, and slug baits.
It is also used as a solid fuel for camp stoves. The dry form looks and tastes like
dog food. Signs of toxicity include excitation, drooling and slobbering, uncoordinated gait, muscle tremors, inability to stand, and continuous seizures that
eventually lead to death from respiratory paralysis. Signs many appear immediately or up to three hours after ingestion. Dogs who survive the acute poisoning may die from secondary liver failure.
Treatment: Treatment is similar to that described for strychnine poisoning
(on this page).
Phosphorus
This extremely toxic chemical is used in rat and roach poisons and is also
found in fireworks, matches, and matchboxes. A poisoned dog may have a
garlic odor to his breath. The first signs of intoxication are vomiting and diarrhea. This is followed by an interval of normal behavior, then by further vomiting, cramps, pain in the abdomen, convulsions, and coma.
Treatment: Induce vomiting (see page 25) when you suspect the dog has
ingested a product or poison that contains phosphorus. Do not coat the bowel
with milk or egg whites, as this can actually promote absorption. Take your
dog to the nearest veterinary facility. There is no specific antidote.
Zinc Phosphide
This substance is found in rat poisons and is used by pest control professionals
as a grain fumigant. Zinc phosphide in the stomach releases gas that has the
odor of garlic or rotten fish. Intoxication causes depression, rapid labored
breathing, vomiting (often of blood), weakness, convulsions, and death.
30 • DOG OWNER’S HOME VETERINARY HANDBOOK
Treatment: Treatment is similar to that described for strychnine poisoning
(page 33). The lavage must be done at a veterinary clinic. There is no specific
antidote. The stomach should be lavaged with 5 percent sodium bicarbonate,
which raises the gastric pH and delays the formation of gas.
INSECTICIDES
There are dozens of products sold at hardware, home repair, and agricultural
stores to kill ants, termites, wasps, garden pests, and other insects. Most of
them contain organophosphates and carbamates as their active ingredients.
With the development of pyrethrin insecticides that are equally effective
but much less toxic, organophosphates and carbamates are being used less
frequently.
Organophosphates and Carbamates
The organophosphates include chlorpyrifos, diazinon, phosmet, fenthion,
cythioate, and tetrachlorvinphos. The common carbamates are carbyl and
propexur. Most cases of organophosphate or carbamate poisoning occur
because the dog ingested a poison bait. Exposure to high concentrations of
chemicals in sprays and dusts also occurs.
Signs of toxicity are hyperexcitability, excessive salivation and drooling,
frequent urination, diarrhea, muscle twitching, weakness, staggering, collapse,
and coma. Death is by respiratory failure.
Treatment: If you suspect that your dog has ingested an insecticide poison,
immediately induce vomiting (see page 25) and notify your veterinarian.
With any sign of toxicity, the first priority is to get your dog to the veterinarian as quickly as possible.
The specific antidote for organophosphate poisoning (not carbamate poisoning) is 2-PAM (protopam chloride). Atropine is given for both organophosphate and carbamate poisoning to control excessive salivation, vomiting,
frequent urination and defecation, and to reverse a slow heart rate. Seizures are
controlled with diazepam (Valium) or barbiturates.
In the event of skin exposure, give the dog a bath with soapy water and
rinse thoroughly to remove residual insecticide.
Chlorinated Hydrocarbons
These compounds, of which the prototype is DDT, are added to sprays and
dusts to control plant pests. Their use has been curtailed because of persistent
toxicity in the environment. Only lindane and methoxychlor are approved
for use around livestock. Chlorinated hydrocarbons are readily inhaled and
easily absorbed through the skin. Toxicity can occur from repeated or excessive exposure.
EMERGENCIES • 31
Signs of toxicity appear rapidly. They include hyperexcitability with twitching of the face, followed by muscle tremors that begin at the head and progress
back to involve the neck, shoulder, trunk, and rear legs. Seizures and convulsions are followed by respiratory paralysis and death.
Treatment: There is no specific antidote. Treatment includes supporting
life functions, removing ingested poison from the stomach, and controlling
seizures.
Pyrethrins and Pyrethroids
These compounds are incorporated into many insecticidal shampoos, sprays,
dusts, dips, foggers, and sprays. Pyrethrins and the synthetic pyrethroids are
much safer to use on and around dogs (and humans) than are other insecticides, and they are being used more widely. Many over-the-counter topical
flea-control products have concentrated pyrethrins as their active ingredients. Some dogs may be adversely affected by that level of pyrethrins.
Common chemicals in this class include permethrin, allethrin, fenvalerate,
resmethrin, and sumethrin.
Signs of toxicity include drooling, depression, muscle tremors, staggering,
vomiting, and rapid labored breathing. Toxicity occurs primarily in small
dogs. Death is rare. Simultaneous exposure to organophosphates increases the
toxicity of pyrethroids.
Treatment: Induce vomiting (see page 25) within two hours of ingestion.
Call your veterinarian for further instructions. Do not induce vomiting if the
product contains a petroleum distillate. With signs of toxicity, proceed immediately to the veterinary clinic.
For topical exposure, remove residual insecticide by bathing the dog in
lukewarm water and Dawn dishwashing soap or canine shampoo to strip out
the chemicals. (Do not use flea shampoo.) Rinse very thoroughly. Bathing in
hot or cold water may actually increase the rate of absorption or cause
hypothermia, which increases toxicity. After bathing, keep the dog warm.
Prevention: Most cases of poisoning occur because of improper application
of flea-control products. That may be because the product is being used more
often than the instructions call for, or is being combined with another fleacontrol product. Follow all instructions carefully.
Arsenic
This heavy metal is used in herbicides, insecticides, and wood preservatives.
Sodium and potassium arsenate are used in ant poisons. Arsenic has a very
rapid action and therefore poses a major risk for accidental poisoning. Death
can occur quickly, even before symptoms are observed. Fortunately, the use of
arsenic has been greatly curtailed.
Signs of poisoning include thirst, drooling, vomiting, staggering, intense
abdominal pain, cramps, diarrhea, paralysis, and death. The breath of the dog
has a strong garlic odor.
32 • DOG OWNER’S HOME VETERINARY HANDBOOK
Treatment: Proceed at once to the nearest emergency veterinary facility.
BAL (British Anti Lewisite) is a specific antidote and should be given as soon
as the diagnosis is suspected.
GARBAGE AND FOOD POISONS
Dogs who scavenge come into contact with garbage, decomposing food, and
carrion, some of which contain endotoxins produced by bacteria and molds.
Once ingested, these endotoxins are absorbed and poison the dog.
Signs appear within two to six hours. They include an acute painful
abdomen accompanied by vomiting and diarrhea (often bloody). The dog
may have noticeably bad breath. Shock and death can occur in severe cases.
Treatment: If you see your dog eating garbage or a dead animal, immediately induce vomiting (see page 25). Follow with liquid Pepto-Bismol; give a
dose every 12 hours for two days. Administer by plastic syringe (see page 572
for more information on administration and dosage). If you have trouble getting the liquid into your dog, use the tablets. Try to keep your dog well
hydrated.
Mild cases recover in one to two days. If the dog begins to vomit or develops other signs of poisoning, notify your veterinarian.
CHOCOLATE
Most dogs like chocolate, but it can be dangerous. Chocolate contains
methylxanthines (made up of caffeine and the alkaloid theobromine).
Methylxanthines are not toxic to people in the concentrations found in
candy and baked goods, but when ingested by dogs the effects can be lethal.
Although some dogs tolerate chocolate far better than others, note that a dog
who weighs 5 to 10 pounds (2.3 to 4.5 kg) could die after eating as little as 4
ounces (113 g) of baking chocolate (not candy); a dog who weighs 20 to 40
pounds (9 to 18 kg) after eating as little as 16 ounces (450 g); and a larger dog
after eating two pounds (about 1 kg). Dogs have been poisoned by eating an
entire pan of brownies or a chocolate cake.
Signs of chocolate toxicity occur within hours after the dog ingests the
chocolate. They include hyperexcitability, vomiting, frequent urination, diarrhea, rapid breathing, weakness, seizures, and coma. Death, which is rare,
occurs by cardiac arrest.
Treatment: If you know your dog has eaten chocolate within the past six
hours and he has not already vomited, induce vomiting (see page 25). Record
the type and amount of chocolate ingested (sweet and semisweet chocolate in
candy bars is not nearly as toxic as baking chocolate). Then call your veterinarian for further instructions.
EMERGENCIES • 33
Prevention: Use commercial dog products as treats. Keep all chocolate
stored securely to prevent accidental ingestion. Make sure everyone in your
family, especially the children, understands that chocolate is dangerous for dogs.
RAISINS, GRAPES, AND OTHER FOOD POISONS
Dogs who eat raisins and grapes are at risk for acute and possibly fatal kidney
failure. Most dogs will vomit some of the raisins or grapes within hours of eating
them, but the damage may already be done. Dogs suffering from grape poisoning
stop eating, develop diarrhea, and become quiet with signs of abdominal pain.
Eventually the blood calcium levels go up and kidney failure follows.
If your dog has eaten raisins or grapes, induce vomiting as soon as you can
and take your dog to your veterinarian. He may need to stay for fluid therapy
to flush out the toxins.
Macadamia nuts are another food that can be toxic to dogs. Dogs who have
eaten these nuts will show mild to severe weakness in the rear legs. So far, dogs
seem to recover with time, but treating with activated charcoal hastens recovery.
Onions have sulfur compounds that can lead to a special type of hemolytic
anemia. This does not usually cause acute toxicity signs, but will be picked up
on blood work. If your dog has ingested onions, induce vomiting and follow
that with activated charcoal.
The active yeast in raw bread dough will produce ethanol as the bread
rises. This can lead to ethanol poisoning in dogs who ingest it. Unsteady gait
and unusual behavior may be the first signs noted. The dog should be taken to
your veterinarian, where fluid therapy, along with activated charcoal and possibly the antidote yohimbine, may be administered.
Xylitol is an artificial sweetener used by many diabetic people and people
who are dieting. Xylitol can cause a dramatic and rapid drop in blood sugar in
dogs, and possibly fatal liver damage. If your dog consumes xylitol, even just
in sugar-free gum, induce vomiting and contact your veterinarian.
CORROSIVE HOUSEHOLD PRODUCTS
Corrosive and caustic chemicals (acids and alkalis) are found in household
cleaners, toilet bowl cleaners, dishwasher detergents, anti-rust compounds,
alkaline batteries, drain decloggers, and commercial solvents. When ingested,
they cause burns of the mouth, esophagus, and stomach. Severe cases cause
perforations of the stomach and strictures of the esophagus, which may
develop over time due to the tissue damage.
Treatment: Do not induce vomiting. Vomiting can result in rupture of the
stomach and burns of the esophagus. Rinse the dog’s mouth immediately after
contact and take him as quickly as possible to the nearest veterinary clinic. If
you can’t get to the vet very quickly, give the dog water or milk (30 ml per 6
34 • DOG OWNER’S HOME VETERINARY HANDBOOK
pounds or 2.7 kg of body weight) by plastic syringe to dilute the acid or alkali
in the stomach.
The practice of giving an acid to neutralize an alkali and vice versa is no
longer recommended, because it causes heat injury to the tissues.
With topical exposure, flush the area with water for 30 minutes. If the substance is in the dog’s eyes, see Burns of the Eyes, page 179.
PETROLEUM PRODUCTS
Gasoline, kerosene, and turpentine can cause pneumonia if aspirated or
inhaled. (Ingesting them usually causes gastrointestinal upset, but is not as
serious.) Signs of toxicity include vomiting, rapid labored breathing, tremors,
convulsions, and coma. Death is by respiratory failure.
Treatment: Do not induce vomiting. Treat as described in the previous section on for corrosive household products (page 34). Flush the mouth with
water to remove petroleum residue. Petroleum products are extremely irritating to the skin and must be removed as quickly as possible. Bathe the skin
using warm soapy water. For tar in the coat, see Special Bath Problems, page 111.
POISONOUS PLANTS
Eating plants and vegetation is not a common cause of poisoning in dogs, but
it does occur. Puppies going through the chewing stage are more likely to
ingest indoor and outdoor plants. In adult dogs, chewing on plants may be a
sign of boredom or frustration associated with separation anxiety or a recent
change in the household routine. The variety of potentially poisonous plants
and shrubs allows for a wide range of symptoms. Signs include mouth irritation, drooling, vomiting, diarrhea, hallucinations, rapid labored breathing,
staggering, muscle tremors, seizures, coma, and death. Some plants cause sudden death without premonitory signs. Other plants contain chemicals that are
extremely irritating to the skin.
Milkweed, lily-of-the-valley, laurel, azalea, foxglove, and oleander all contain cardiac glycosides of the digitalis class. Even though these plants have a
bitter taste, pets do sometimes eat enough to cause death. Ornamental plants
of the nightshade family, including Chinese lantern, Christmas cherry, and
ornamental pepper, contain solanines that are toxic to the gastrointestinal
system and brain. They, too, are a rare cause of death.
You’ll find a list of common toxic plants, shrubs, and trees on pages 36–38,
but this list does not include all potentially poisonous plants. If you’re not sure
about a plant, ask your veterinarian or the local plant nursery. The ASPCA
also has a list of poisonous plants on its website (www.aspca.org). Your local
Cooperative Extension is often a good source of information about poisonous
plants. Note that with some plants, only certain parts are toxic. With others,
the whole plant is poisonous.
EMERGENCIES • 35
Treatment: If you suspect your dog has ingested a poisonous plant, induce
vomiting (see page 25) and call your veterinarian for further instructions.
Prevention: To prevent houseplant poisoning, determine which plants are
toxic and either dispose of them or keep them in a place the dog is unable to
reach. Outside, be careful of any sticks you throw for your dog that he may
chew on. Fence off dangerous plants so your dog can’t reach them.
Indoor Plants with Toxic Effects
Houseplants that cause a skin reaction after contact with the skin or mouth
Chrysanthemum Poinsettia
Creeping fig Weeping fig
Irritating plants, some of which contain oxalic acid, which causes mouth swelling,
difficulty swallowing, respiratory problems, and gastrointestinal upsets
Arrowhead vine Malanga
Boston ivy Marble queen
Caladium Mother-in-law plant
Calla or arum lily Neththyis
Dumbcane (diffenbachia) Parlor ivy
Elephant’s ear Pothos or devil’s lily
Emerald duke Peace lily
Heart leaf (philodendron) Red princess
Jack-in-the-pulpit Saddle leaf (philodendron)
Majesty Split leaf (philodendron)
Tuberous begonia
Plants that contain a wide variety of poisons—most cause vomiting, an acutely
painful abdomen, and cramps; some cause tremors, heart and respiratory and/or
kidney problems, which are difficult for owners to interpret
Amaryllis Ivy species
Asparagus fern Jerusalem cherry
Azalea Nightshade
Bird-of-paradise Pot mum
Creeping Charlie Ripple ivy
Crown of thorns Spider mum
Elephant’s ear Sprangeri fern
Umbrella plant
36 • DOG OWNER’S HOME VETERINARY HANDBOOK
Outdoor Plants with Toxic Effects
Outdoor plants that can cause vomiting and diarrhea
Bittersweet woody Indian turnip
Castor bean Indian tobacco
Daffodil Larkspur woody
Delphinium Poke weed
Foxglove Skunk cabbage
Ground cherry Soapberry
Wisteria
Trees and shrubs that may cause vomiting, painful abdomen, and diarrhea
American yew English yew
Apricot Horse chestnut
Almond Japanese plum
Azalea (rhododendron) Mock orange
Balsam pear Monkey pod
Bird-of-paradise bush Peach
Buckeye Privet
Cherry Rain tree
English holly Western black locust yew
Wild cherry
Outdoor plants with varied toxic effects
Angel’s trumpet Mescal bean
Buttercup Moonseed
Dologeton Mushrooms
Dutchman’s breeches Nightshade
Jasmine Pigweed
Jimsonweed Poison hemlock
Locoweed Rhubarb
Lupine Spinach
May apple Sunburned potato
Matrimony vine Tomato vine
Water hemlock
continued
EMERGENCIES • 37
Outdoor Plants with Toxic Effects (continued)
Hallucinogens
Locoweed Nutmeg
Marijuana Periwinkle
Morning glory Peyote
Poppy
Outdoor plants that cause convulsions
Chinaberry Nux vomica
Coriaria Water hemlock
Moonweed
LEAD
Lead is found in fishing weights and is a base for some artists’ paints. Other
sources of lead include linoleum, drywall (sheetrock), batteries, plumbing
materials, putty, lead foil, solder, golf balls, old paint chips, and tar paper. The
use of commercial lead-free paints has significantly reduced the frequency of
lead intoxication. Poisoning occurs primarily in puppies and dogs who chew
and swallow objects that contain lead. Toxicity usually requires repeated
exposure.
Acute lead intoxication is characterized by vomiting and a very painful
abdomen. With chronic exposure, a variety of central nervous system signs
can develop. They include seizures, uncoordinated gait, excitation, continuous barking, attacks of hysteria, weakness, stupor, and blindness. Chewing and
champing fits may be mistaken for the encephalitis of distemper.
Treatment: If you suspect your dog has ingested lead, induce vomiting (see
page 25). Seek veterinary attention. Blood tests will be done to check for lead
levels. Specific antidotes to bind and remove lead from the dog’s system are
available from your veterinarian.
ZINC
Pennies made after 1982 have a zinc core. This heavy metal can be toxic to
dogs, leading to hemolytic anemia, blood in the urine, and possible kidney
failure. If you see your dog ingest pennies, induce vomiting. Many times, clinical signs do not show up for days, as the stomach acid dissolves the metal.
Surgery to remove any pennies may be required and your dog may need hospitalization for fluids and to attempt therapy to chelate (remove from the body)
the zinc.
38 • DOG OWNER’S HOME VETERINARY HANDBOOK
TOAD AND SALAMANDER POISONING
There are two species of poisonous toads in the United States: the Colorado
River toad, found in the Southwest and Hawaii; and the marine toad, found
in Florida. There is one species of poisonous salamander: the California newt,
found in California.
All toads, even the ones that aren’t poisonous, have a bad taste. Dogs who
mouth them slobber, spit, and drool. This does not necessarily mean the dog
has been poisoned. Toxicity depends upon the virulence of the toad or salamander venom, the size of the dog, and the amount of poison absorbed. The
marine toad, for example, is highly poisonous, causing death in as few as 15
minutes.
Symptoms can vary from slobbering to convulsions, blindness, and death.
Puppies and small dogs are more likely to develop toxicity.
Treatment: Repeatedly flush the dog’s mouth using a garden hose, if necessary, and induce vomiting (see page 25). Be prepared to administer CPR (see
page 8). Dogs with salamander poisoning generally recover quickly.