Common Toxin Emergencies

COMMON TXIN EMERGENCIES

Tami Lind, BS, RVT, VTS(ECC)

Dogs, cats, birds and most animals love to sink their teeth into something that is unknown to them. Unfortunately, this can lead to some major problems and land them in the emergency hospital for toxin ingestion. In 2018, the top 10 toxins that the ASPCA Animal Poison Control Center took calls on were over-the-counter medications; prescription medications; food such as xylitol, grapes, and raisins; chocolate; veterinary products; household items like paint and glue; rodenticide; insecticide; plants; and garden products. A clear patient history and owner’s trust is key to ensuring we can help their pet.

If a pet comes into the hospital and a toxin is suspected, but the owners do not know what was ingested, you will have to treat based on symptoms alone. Vomiting, diarrhea, neurologic issues, distressed GI and hypersalivation are just some of the symptoms that can appear due to toxin ingestion. It is vital you ask the client about the possibility of drugs, cleaners, foods, plants and other poisons so that treatment can be as focused as possible.

Decontamination is also a very important step when dealing with toxin ingestion. Decontamination is different for different toxins. Decontamination techniques can include bathing for topical toxins or the use of activated charcoal/emesis for ingested toxins. Supportive care after decontamination includes serial monitoring of vital signs and possibly diuresis, dialysis, and monitoring of kidney, liver, and electrolyte values.

Common toxins and treatments:

Food:

Chocolate toxicity is most common in dogs. The clinical signs, caused by theobromide and caffeine, include vomiting and diarrhea, tachycardia, muscle tremors, seizures, coma, and death. Decontamination and the administration of activated charcoal are the first steps. Secondary steps would include IV fluid administration, if clinical signs warrant this measure. Propranolol can be prescribed to decrease heart rate, if necessary.

With these calculations, you can easily figure out if the amount of chocolate ingested is toxic: • Milk Chocolate: wt (#) x 0.3 = oz needed for reaction • Dark Chocolate: wt (#) x 0.12 = oz needed for reaction • Baking Chocolate: wt (#) x 0.04 = oz needed for reaction

Grapes and raisins are also a common food ingested by our canine patients. Unfortunately, the mechanism of action and toxic agent is unknown. These can cause gastrointestinal irritation as well as renal toxicity. The majority of dogs show clinical signs of vomiting Patient experiencing marijuana toxicity. Image courtesy of Tami Lind.

within 24 hours of ingestion. Renal bloodwork changes occur within 24 hours of ingestion and declines around 48–72 hours. Decreased urine output and lethargy can occur after five days. When a patient first presents with grape toxicity, vomiting can be induced. Activated charcoal can be given, but there is limited evidence on if it actually is effective. IV fluids can help preserve the kidneys and keep the patient hydrated. Chemistry values should be monitored over 48 hours. If AKI persists, dialysis may be considered.

Xylitol is a sugar substitute showing up in multiple products and people are using it more in baking and cooking over sugar. Xylitol can cause an insulin release in dogs leading to hypoglycemia. If patients ingest higher doses, it can lead to hepatic failure. The effect of Xylitol on cats is widely unknown. When patients come in that have ingested xylitol, vomiting may or may not be effective depending on when they ingested the toxin. Xylitol is absorbed into the body very quickly, so inducing vomiting can prove ineffective. If gum containing xylitol is ingested, inducing vomiting can be effective if the gum was ingested within a short

window. Intravenous dextrose, even in asymptomatic patients, can came in. Color and consistency of the rodenticide cannot always ensure that patients will not become hypoglycemic. Liver and GI be used because most rodenticides come in a green color and protectants should also be used. have the same consistency. The three major types of rodenticides encourage the client to bring in the packaging that the rodenticide are anticoagulant rodenticides, cholecalciferol rodenticides and Medications: bromethalin rodenticides. Acetaminophen is a common over-the-counter medication • Anticoagulant rodenticides: Anticoagulant rodenticides for pain control in humans. When our patients eat this, it can inhibit the activity of vitamin K. Vitamin K is required to be very detrimental for their health. Cats have an increased fully activate coagulation factors II, VII, IX and X. When sensitivity to acetaminophen. The metabolism of the drug in a patient cannot activate coagulation factors, clinical signs both dogs and cats can lead to hepatic failure. GI signs occur of bleeding are observed. Patients will often come in with a first, followed by facial edema and cyanosis. Acetaminophen also history of coughing up blood, nasal bleeding or lacerations causes methemoglobinemia, a disorder in which hemoglobin is that will not stop bleeding. Other clinical signs can include damaged and hangs on to oxygen instead of releasing it to tissues. lethargy, anorexia, weakness and shock. PT/PTT should be This is characterized by brown mucus membranes and chocolate tested when anticoagulant rodenticide is suspected as PT/ brown blood. Hypoxia occurs in these patients. Heinz bodies PTT will be elevated. Vitamin K is the typical treatment for can form on red blood cells causing them to be destroyed, and anticoagulant rodenticide. If bleeding is already occurring, anemia can also occur. Acetaminophen toxicity is treated first blood products should be used. Vitamin K is a fat-soluble with decontamination and activated charcoal. The treatment for vitamin, so it is best absorbed orally with food. If the patient acetaminophen is N-Acetylcysteine, (140mg/kg loading dose, is not eating, it can be given subcutaneously. 70mg/kg q6h for seven treatments), and can be administered either • Cholecalciferol rodenticides: Cholecalciferol is Vitamin IV (filter recommended) or PO. N-Acetylcysteine should be diluted D3 and its ingestion results in hypercalcemia and to a 5% solution before patient administration. Treatment also can hyperphosphatemia. This will lead to PU/PD, GI signs, include vitamin C (thought to reduce methemoglobinemia), GI muscle weakness and renal failure. If the patient is seen protectants, oxygen and supportive care. quickly, emesis and repeated doses of activated charcoal should be used. IV Sodium Chloride should be given for Toxic doses of acetaminophen: a few days. This reduces calcium reabsorption in the renal • Cats: 5–10mg/kg toxic dose tubules and enhances urinary calcium excretion. • Dogs: >50mg/kg toxic dose • Bromethalin rodenticides: Bromethalin is metabolized by the liver into a more toxic product: desmethyl bromethalin. Non-steroidal anti-inflammatories, or NSAIDS, are also a Both products are lipid-soluble, so the bromethalin common over-the-counter medication that humans take. Clinical accumulates in the brain and fat. Brain edema and lipid signs often include vomiting and diarrhea and can also lead to peroxidation occur and can cause cellular damage and GI ulceration. At higher doses, renal toxicity can occur. In both necrosis. Patients may present with ataxia, hind limb paresis, cases, decontamination, activated charcoal and GI protectants paralysis, seizures, tremors, hyperexcitability hyperthermia, are recommended. Treatment includes IV fluids and possibly circling, CNS depression and death. Stimulating emesis misoprostol to protect against GI ulceration. Chronic use of and activated charcoal are best for decontamination. If NSAIDS in patients can result in liver damage. the patient is already neurologic, emesis would not be Rodenticides: is guarded to grave. Lipid emulsion therapy, early in the As there are multiple different types of rodenticides, it is essential course of toxicity, has been proposed as a possible “antidote” to know what type of rodenticide the pet has ingested. Always for this toxin. effective. Once the patient develops clinical signs, prognosis

Pesticides/Antiparasitics:

Pyrethrins are generally used as topical medications for flea repellants. If a feline patient comes in contact with certain topical canine flea medications, they may present with tremors which can be mistaken for seizures. These patients are still aware of their surroundings. When a patient comes in with pyrethrin toxicity, the first treatment should be to bathe them with a dish soap to cut through the medication and remove it. Muscle relaxants can assist with decreasing the muscle tremors. It is imperative that temperature is monitored. IV lipid emulsion has been used and seems to help with the muscle tremors of patients. There are limited studies on the use of lipids with pyrethrins. The most common pyrethroid that the ASPCA Animal Poison Control Center received questions about from Florida was Giving patients a bath is a decontamination technique when a topical toxin has been identified. Image courtesy of Tami Lind. etofenprox.

This patient was given apomorphine after he ingested rodenticide. Image courtesy of Tami Lind.

Lipids can be used in multiple toxicities. Lipids have a long shelf life and are relatively inexpensive. Image courtesy of Tami Lind.

Ivermectin is another antiparasitic that is used for endo- and ectoparasites in dogs and cats. It is available over-the-counter in oral and injectable form. Patients that experience ivermectin toxicity usually present with ataxia, paralysis, bradycardia, blindness, coma or are dead upon arrival. Ivermectin, in high doses, crosses the blood brain barrier and enters the CNS and prevents neuron depolarization. Treatment consists of decontamination, multiple doses of activated charcoal, IV lipids can also be used since ivermectin is lipid soluble. Do not use benzodiazepines to treat seizures as this may not help the seizures.

Plants:

Sago palms are usually found in tropical areas. All parts of this plant are toxic, and we mostly see feline patients for this toxicity. Cycasin is the most toxic element of the plant. Cycasin can cause hepatotoxicity and is also a GI irritant. It can also cause cerebellar necrosis, which can cause ataxia. These patients will come in with vomiting, diarrhea, melena, icterus, ataxia, and, possibly, seizures and death. There is no antidote, so emesis, activated charcoal, IV fluids and GI protectants will be needed. Sometimes, even with treatment, the patient may need lifelong hepatic support. Canine patients may also come in because they have eaten the seed of the sago palm tree. This can cause a mechanical obstruction and may need surgery.

Lilies are found in many gardens and especially in many bouquets around Easter time. All parts of the lily are toxic. If a patient even just nibbles on a leaf of a lily, it can cause toxic effects. These patients will present with vomiting, depression and, eventually, renal failure. If patients are exposed for an extended period of time, they can present with CNS signs which include ataxia, head pressing and seizures. Treatment includes emesis and, if possible, IV fluids, activated charcoal and/or hemodialysis. Kidney values should be monitored daily for 48–72 hours. Marijuana is starting to become legal in more states and comes in many forms. Pets are exposed via ingestion and secondhand smoke. The active ingredient in marijuana is tetrahydrocannabinol (THC). THC is a depressant that interacts with many neurotransmitters. Patients will present to the hospital with mental depression, hyperesthesia, ataxia, tremors, mydriasis or miosis, hypothermia, bradycardia, and respiratory depression. Patients are also known to “dribble urine” and act like they are falling asleep standing up. With marijuana being laced with more potent medications, patients often come in with more profound clinical signs, leading to coma and possibly death. “Marijuana brownies” are also common with our patients. This can pose two toxin challenges and should be treated at the same time. If a patient comes in quickly after ingestion, emesis can be initiated. Do not induce vomiting if neurologic signs are already present. Activated charcoal can be given with repeated doses. Treatment after decontamination consists of IV fluids and supportive care. THC is a lipid-soluble toxin, so IV lipids can be used to possibly speed up recovery.

There are so many more products, plants, food and medications that pets can get into. When a patient comes into the clinic after ingesting a known toxin, it is important that either the owner or your practice calls poison control.

Tami Lind, BS, RVT, VTS(ECC)

Tami Lind is the current ICU and ER supervisor at Purdue University. She has been at the university for ten years. She attended the veterinary technology school at Purdue and graduated in 2010 with her bachelor’s degree in veterinary technology. Since then, she has never left! Lind started as a veterinary technician in the ICU, and she has been the supervisor of the ICU/ ER since 2012. She received her VTS in emergency and critical care in October 2016. She enjoys teaching new veterinary technicians and veterinary students. She strives to prepare them for their careers ahead.