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Pet Owner Version

Poisonings from Illicit and Abused Drugs


Safdar A. Khan

, DVM, MS, PhD, DABVT, ASPCA Animal Poison Control Center, Urbana, Illinois

Reviewed/Revised Oct 2020 | Modified Nov 2022

If your pet has been exposed to illicit or abused drugs, it is important that you provide an accurate and complete history to your veterinarian. This information is critical for your veterinarian to be able to make an accurate diagnosis and provide appropriate treatment. Illicit drugs are often adulterated with other pharmacologically active substances, which makes the diagnosis even more difficult. As with any potential poisoning, critical information includes the amount your pet has eaten, the amount of time between ingestion and appearance of signs, and a description of all signs that have developed.


Cocaine is obtained from the leaves of the coca plant. Common street names for cocaine include coke, gold dust, stardust, snow, “C”, white girl, white lady, baseball, and speedball (cocaine and heroin). Free base cocaine is also called crack, rock, or flake. Cocaine is often “cut” or diluted with other substances, such as xanthine alkaloids, local anesthetics, and decongestants. Cocaine is primarily used illegally by people as a recreational drug, but it also has medical use as a topical anesthetic on the mucous membranes of the mouth, larynx, and nasal passages.

Cocaine poisoning is characterized by hyperactivity, shaking, lack of coordination, panting, agitation, nervousness, seizures, a rapid heartbeat, metabolic abnormalities, and fever. Central nervous system depression and coma may follow. Death may be due to very high fever or cardiac or respiratory arrest.

Diagnosis is based on a history of exposure and the characteristic signs. Identification of cocaine in blood, stomach contents, or urine can confirm exposure.

Animals with signs will need to be stabilized first before treatment can be attempted. Vomiting can be induced in a recent exposure if the animal is showing no signs. This should be followed by administration of activated charcoal with a medication that causes emptying of the bowels. If the animal’s condition makes it inadvisable to induce vomiting (for example, presence of central nervous system signs or extremely rapid heartbeat) flushing the stomach should be performed.

Anticonvulsants and tranquilizers are used to control the central nervous system effects. Blood pressure, heart rate and rhythm, and body temperature will to be monitored often and treated as needed. Fluids should be administered and metabolic abnormalities monitored and corrected as needed. Treatment and monitoring should continue until all signs have resolved.

Amphetamines and Related Drugs

Amphetamines stimulate the central nervous system and the cardiovascular system. In people, amphetamines and their derivatives are commonly used for depression of appetite, narcolepsy, attention deficit disorder, Parkinson’s disease, and some behavior disorders. Some common amphetamines or related drugs are benzphetamine, dextroamphetamine, pemoline, methylphenidate, phentermine, diethylpropion, phendimetrazine, methamphetamine, and phenmetrazine. Amphetamines sold on the street are often called speed, bennies, or uppers, and they are commonly “cut” or diluted with caffeine, ephedrine, or phenylpropanolamine.

Signs of amphetamine and cocaine poisoning are very similar. The only difference may be that the signs of amphetamine poisoning last longer. The most common signs are hyperactivity, aggression, fever, tremors, lack of coordination, a rapid heartbeat, high blood pressure, enlarged pupils, circling, and death.

Diagnosis and treatment are as for cocaine (above), and the history given by the owner is extremely important. Most amphetamines and related drugs can be detected in stomach contents and urine.

Phenothiazine tranquilizers are used to control central nervous system signs in amphetamine poisoning. Anticonvulsants are used if needed. Heart rate and rhythm, body temperature, and electrolytes should be monitored and treated as needed.


Marijuana refers to a mixture of cut, dried, and ground flowers, leaves, and stems of the leafy green plant Cannabis sativa. The plant grows in most tropical and temperate regions of the world. Street names for marijuana include pot, Mary Jane, hashish, weed, grass, THC, ganja, bhang, and charas. Marijuana or hashish sold on the streets may be contaminated with phencyclidine, LSD, or other drugs.

In the recent past, marijuana has been primarily used illegally by people as a recreational drug, but by 2019 medical use had been legalized in 33 US states, and 11 of those have also legalized recreational use. It does, however, remain classified as a Schedule I Controlled Substance by the US Drug Enforcement Agency, and there are no FDA-approved uses. Also, there are no FDA-approved products for use in animals, and states that have legalized use in humans have not approved veterinary use.

In dogs, the most common route of exposure is ingestion. Signs begin within 30 to 90 minutes and can last up to 3 days. The most common signs of poisoning are depression, lack of coordination, slow heart rate, dangerously low body temperature, vocalization, excessive drooling, vomiting, diarrhea, inability to control urination, seizures, and coma. This can be confused with other causes of poisoning, low blood sugar, back problems, or head trauma.

Diagnosis is based on a history of exposure and typical signs. Marijuana is difficult to detect in body fluids, however, urine testing in the early course of exposure may help confirm the diagnosis.

Treatment consists of supportive care, including medication to control seizures. Vomiting can be induced if the exposure is recent and the animal is not yet showing signs. Comatose animals should be given intravenous fluids and treated for dangerously low body temperature. Their position should be changed often to prevent fluid buildup and pressure sores. Treatment and monitoring should continue until all signs have resolved (up to 3 days in dogs).


The term opioid refers to all drugs, natural or synthetic, that have morphine-like actions. Some of the common opioids are morphine, heroin, hydromorphone, oxymorphone, hydrocodone, codeine, oxycodone, butorphanol, methadone, propoxyphene, meperidine, diphenoxylate, fentanyl, loperamide, profadol, pentazocine, and buprenorphine. Tramadol is a synthetic opiate that is a derivative of codeine and is widely used in veterinary medicine as a pain reliever.

Opioids are used primarily as pain relievers, but also as cough suppressants and to treat diarrhea. Occasionally, opioids are also used for sedation before surgery and as a supplement to anesthesia. Toxicity of opioids in animals varies greatly among different species.

The primary effects of opioids are on the central nervous system, and on the respiratory, cardiovascular, and gastrointestinal systems. Common signs of poisoning include central nervous system depression, drowsiness, lack of coordination, vomiting, seizures, constricted pupils, coma, depressed breathing, low blood pressure, constipation, and death. Some animals—especially cats and horses—can show central nervous system excitation instead of central nervous system depression.

Diagnosis of opioid poisoning is based on a history of exposure and the signs. Urine can be analyzed to determine exposure to opioids.

Signs can be reversed with naloxone. Administration of naloxone should be repeated as needed because its duration of action may be shorter than the opioid being reversed. Animals should be closely monitored for depressed breathing and a ventilator provided if needed. Other signs should be treated symptomatically.

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