The solution to pollution: Top veterinary toxicity tips

November 13, 2020
Amanda Carrozza
Amanda Carrozza

Amanda Carrozza is a freelance writer and editor in New Jersey.

The prevalence of poison exposure in companion animals remains higher than ever. Make sure you know how typical toxins are treated.

According to data released by the ASPCA Animal Poison Control Center (APCC), its agents fielded more than 232,000 calls about animals exposed to potentially harmful toxins in 2019. This was an increase of nearly 10% from the previous year.

Are you confident in your knowledge of common household items that may be toxic to companion animals? Do you know when inducing emesis might be dangerous?

Thankfully, Liz Hughston, MEd., RVT, CVT, LVT, VTS (SAIM) (ECC), is well versed in identifying and treating veterinary toxicity cases and recently shared her knowledge with attendees at the Fetch dvm360® virtual conference.

“Toxicities are among my favorite emergencies to treat,” Hughston, the founder of VetTechXpert, said at the beginning of the presentation. “I find them very fulfilling because often times you will get immediate job satisfaction. You will know you have really helped the patient because you get to see the results pretty quickly.”

Top toxins

Chocolate remains the most reported toxin ingested by dogs, according to the Pet Poison Helpline, followed by rodenticides, anti-inflammatory medications, xylitol, and grapes/raisins.

It is always an emergency if a dog eats raisins or grapes because of the unpredictable reaction, Hughston said. “We do not know the toxic principle behind it. Some dogs can eat many grapes and have no problem, but another dog might eat just 1 grape or raisin and immediately go into kidney failure.”

In cats, the Pet Poison Helpline pinpointed lilies as the most frequently reported toxin, followed by insecticides (primarily dog flea medication), household cleaners, antidepressant medications, essential oils, and anti-inflammatory medications.

Although not listed by the Pet Poison Helpline, Hughston noted that tetrahydrocannabinol(THC, the main psychoactive component of marijuana) toxicity is becoming increasingly prevalent and requires immediate attention. “THC toxicity—coming from marijuana as opposed to hemp,” she clarified, “is usually a very dramatic toxicity. People are going to want their pets treated because it looks very scary, even though it is not necessarily dangerous in and of itself.”

Toxicity treatment basics

As in any emergency, it is crucial to ensure the patient remains stable. “We always want to make sure we are paying attention to the airway, breathing, and circulation,” Hughston said. “This part is really important because whether or not you have a toxicity you are trying to treat, if your patient is not alive your treatment is not going to be successful.” Treat what kills first.

While the patient is being stabilized, support staff should obtain as much information from the client as possible. “This is a really valuable role for veterinary technicians to play,” she explained. “You need to know exactly what the patient got into, when they were exposed, how much were they exposed to, and how they got into it.”

Ideally, clients should be encouraged to bring in any packaging or bottles the pet came in contact with. This will provide crucial information about active and inactive ingredients as well as the concentration of the product. “This is especially important when talking about things like iron, fertilizers, or snail bait because there are different concentrations,” Hughston said. “We need to look at what concentration we are dealing with so we can calculate the amount of toxic ingestion or application.”

In the absence of packaging, online searches can help identify active ingredients and contents if the pet owner knows the brand name.

In addition to information about the exposure, staff should record current medications and any significant ongoing health conditions, such as asthma or heart disease. Hughston suggested using the toxin exposure triage form provided by the ASPCA APCC as a guide for ensuring all pertinent information is collected.

The solution to pollution is dilution

Once the patient is stable, the toxicant has been identified, and the details of the exposure are known, measures should be taken to prevent further absorption. “As much of the toxin we can remove or prevent from being absorbed, the better,” she said.

In most cases of toxicity, dilution is the most successful remedy.

External decontamination

For patients with topical exposure, bathe the patient in tepid water to remove as much of the contaminant from the skin or fur as possible. Rinse the affected area for a minimum of 10 minutes, and longer if signs persist.

To avoid aspiration, take extra care when bathing patients that are recumbent or have reduced responsiveness or reflexes, she advised. Additionally, dry the patient thoroughly and check core body temperature frequently to avoid hypothermia.

Internal decontamination

When a patient has ingested a toxin, inducing emesis is generally the first step in gastrointestinal (GI) decontamination. For dogs, Hughston prefers using a compounded apomorphine injectable, which causes vomiting within 2 to 3 minutes after administration.

In June of this year, the FDA approved the use of ropinirole ophthalmic solution (Clevor, Orion Corp) for the induction of vomiting in dogs.In a clinical field efficacy study in which Clevor was administered to 100 client-owned dogs to induce vomiting of their last meal (no toxins or harmful objects were given to the dogs), 95% vomited within 30 minutes. Emesis occurred after the first dose in 86% of the dogs. “This is a nice option if you have a canine patient who is constantly getting into things. It can be useful for the client to have these drops at home,” Hughston said.

While very useful in dogs, apomorphine is not an effective emetic agent in cats because cats do not have as many dopamine receptors, she said. Veterinary professionals often spin feline patients to make them dizzy and induce vomiting. “But there are more effective options,” Hughston said. Alpha-2 agonists, including xylazine or dexmedetomidine, are better choices.

Hughston also highlighted a 2019 study published in the Journal of Veterinary Emergency and Critical Care that examined the efficacy of hydromorphone for inducing vomiting in cats. The researchers found that emesis was successful in 75% of cats treated with hydromorphone (0.1 mg/kg subcutaneously) and resulted in less sedation and less decrease in heart rate.

Emesis is not always the answer

There are certain instances when emesis could prove dangerous, Hughston warned. This is especially true if a patient is already vomiting, experiencing respiratory distress, or has ingested caustic or corrosive agents that may cause damage to the GI tract.

When emesis is not encouraged, Hughston offered various alternatives for removing or diluting the toxicity:

  • Adsorption: Activated charcoal can be administered in many toxicity cases to prevent absorption from the GI tract. The charcoal will adsorb certain toxic agents and facilitate excretion.
  • Cathartic agents: Sorbitol, lactulose, magnesium salts, or bulk fiber can be used to speed the transit of a toxicant through the GI tract. The increased speed decreases chances of absorption from both the large and small intestines.
  • Dilution: Induction of emesis is contraindicated when caustic or corrosive agents are ingested. Instead, dilution with milk or GI-coating agents (eg, milk of magnesia) is necessary. “Don’t forget the value of IV fluids both as a toxin diluter and as a patient supportive care measure,” she added.
  • Gastric lavage: Ingestions of hydrocarbons, caustic substances, or very lethal toxicants may require gastric lavage, Hughston said. Gastric lavage requires general anesthesia and must always proceed with a cuffed endotracheal tube in place to protect the airway from both lavage fluid and stomach contents.
  • Surgical removal: If the toxicant is solid (eg, intact batteries, pennies), endoscopic or surgical removal is the most effective method to prevent absorption.

Regardless of the toxicant, supportive care is essential to positive patient outcomes. “Veterinary professionals who are familiar with toxicology concepts and treatments are crucial to ensuring that patients recover with minimal long-lasting effects,” Hughston reminded attendees.

Amanda Carrozza is a freelance writer and editor in New Jersey.