The Essentials of Veterinary Toxicology | Free Vet E-Book by Dr. Carey Hemmelgarn

At some point, the call comes. A dog got into the rodenticide under the sink. A cat walked through bleach and licked her paws. A client is on the way in with a dog who ate an unknown number of ibuprofen tablets forty minutes ago and they are not sure how many were in the bottle.

Toxicology cases are not rare. They are not something you can wait to learn about until you encounter one in the clinic. By the time the patient is in front of you, you need a framework already in place — one that tells you what to ask, what to do first, and what the worst-case scenario looks like before it happens.

Vet Candy's Essentials of Veterinary Toxicology was built to give you that framework.

Who Wrote It

Dr. Carey Hemmelgarn is not writing from a textbook. She is writing from the treatment floor.

A veterinary criticalist and co-founder of Intensivets — an online veterinary education platform — Dr. Hemmelgarn completed her veterinary degree at Washington State University, followed by a one-year rotating internship at Garden State Veterinary Specialists and a three-year emergency and critical care residency at Oradell Animal Hospital in Paramus, New Jersey. She currently practices at Blue Pearl Veterinary Partners in Brooklyn, New York, where she has spent her career managing exactly the kinds of cases this e-book covers.

She has gotten the toxicology calls. She has triaged the dog who ate the entire rat bait station. She has managed the cat who walked through a permethrin product and presented seizing. She has made the decision about whether to induce emesis in a neurologically compromised patient at midnight with no toxicologist on call.

This e-book is what she knows. Organized, written down, and made free for every veterinary professional who needs it.

What the Fundamentals Actually Teach You

Most clinical resources skip the basics and go straight to the toxins. Dr. Hemmelgarn does not, and she is right not to.

The opening chapter on basic toxicology principles and terminology is not throat-clearing. It is the conceptual infrastructure that makes every clinical decision downstream make sense. What is the difference between acute, subchronic, and chronic toxicity? How does bioavailability affect the severity of an exposure? Why do cats respond differently to so many toxins that dogs tolerate without issue? What does lipid solubility tell you about how long a substance is going to stay in a patient's system?

The ADME framework — absorption, distribution, metabolism, excretion — is covered in clinical terms, not pharmacology lecture terms. Dr. Hemmelgarn explains how underlying organ disease changes the trajectory of a toxicity, how enterohepatic recirculation complicates decontamination, and why the half-life of a toxin matters when you are deciding how many doses of activated charcoal to give.

These are the building blocks. If you understand them, the rest of the e-book is not memorization. It is application.

Triage and Decontamination: The Decisions That Define the Outcome

The triage chapter is where this e-book earns its place in your clinical toolkit.

Dr. Hemmelgarn walks through the toxicology history methodically — what to ask, how to calculate worst-case dosage, what underlying conditions and current medications change the picture. She covers the ABCs of patient assessment in the context of toxicity specifically, including the cardiovascular, respiratory, and neurological signs that demand immediate intervention.

The treatment protocols in this section are organized and specific. Seizure management including midazolam, diazepam, levetiracetam, and phenobarbital. Cardiac arrhythmia protocols including sinus tachycardia, ventricular tachycardia, atrial standstill, and sinus bradycardia with the appropriate first-line agents for each. Hypovolemic shock management with fluid bolus dosing for canine and feline patients — including the conservative rates cats require. Vasopressor selection when fluids are not achieving normotension.

The decontamination section is the most practically comprehensive you will find in a free resource. Emesis induction in dogs — apomorphine, Clevor (ropinirole ophthalmic solution, the first FDA-approved emetic eye drop for dogs), and the evidence against hydrogen peroxide including the gastroduodenal ulceration data. Emesis induction in cats — dexmedetomidine, xylazine, and hydromorphone with comparative efficacy data. Activated charcoal protocols including the sorbitol question and when to repeat dosing. Gastric lavage indications including bread dough, yeast products, and specific high-toxicity situations. Dermal decontamination. Ocular decontamination.

This is the chapter that pays for itself the first time you use it.

The Toxins You Will Actually See

The clinical chapters are organized around how toxicology cases actually present in practice — by toxin category rather than by organ system — which makes this a far more useful reference than most clinical guides.

Poisonous plants covers the species your clients have in their homes and gardens and never think twice about. Lilies — the complete nephrotoxic picture for cats, including the unknown toxic principle, the timetable for renal failure, and the critical importance of IV fluid diuresis before azotemia develops. Sago palm — the three toxic compounds, the hepatotoxic progression, and the sobering survival statistics. Rhododendrons and oleander — grayanotoxin and cardiac glycoside toxicity respectively, both with the cardiovascular complications that catch clinicians off guard. Castor bean, yew, tulips, poinsettia, aloe vera, and more — each with the clinical signs and treatment approach that matters most.

Common household hazards covers the things your clients have in every room of their house. Xylitol — the insulin surge mechanism, the dose thresholds for hypoglycemia versus hepatic necrosis, the 72-hour monitoring protocol, and liver protectant selection. Grapes and raisins — idiosyncratic toxicity, treat every ingestion as toxic, 48-hour IV fluid diuresis. Allium species — Heinz body anemia, species sensitivity, transfusion thresholds. Gorilla glue and diisocyanate adhesives — gastric expansion, no emesis, surgery is the only option. Laundry pods — aspiration risk and chemical pneumonia. Batteries — liquefaction necrosis and the specific danger of lithium button batteries. Pennies — zinc toxicity, immune-mediated hemolytic anemia, endoscopy protocol.

The rodenticide chapter is one of the most clinically useful sections in the e-book because it covers all four major categories in one place. Anticoagulant rodenticides — first and second-generation, duration of action, clotting factor cascade, the PT timing, vitamin K1 dosing for 30 days and the 48-hour recheck protocol. Bromethalin — the neurotoxin with no antidote, early decontamination is everything, the delayed paralysis picture that can catch you weeks later. Cholecalciferol — rising popularity as anticoagulants are phased out, hypercalcemia and hyperphosphatemia leading to acute kidney failure, bisphosphonate therapy. Phosphide rodenticides — phosphine gas generation, the ventilation requirement when inducing emesis, supportive care only.

The human medications chapter covers the drugs that end up in pets every single day. NSAIDs in depth — COX-1 and COX-2 mechanism, GI and renal vulnerability, species differences, enterohepatic recirculation and multi-dose charcoal, sucralfate, misoprostol, and 48-96 hours of IV fluids. Acetaminophen — the glucuronidation deficiency in cats, NAPQI accumulation, methemoglobinemia, the n-acetylcysteine protocol, cimetidine and ascorbic acid combination therapy. Albuterol inhalers — hypokalemia from intracellular shift, cardiac arrhythmias, no decontamination possible because it is inhaled. Antidepressants — TCAs, MAOIs, and SSRIs covered individually with mechanism and treatment. Baclofen, nicotine, ADHD medications, illicit recreational drugs including marijuana, cocaine, opiates, and benzodiazepines.

The insecticides chapter covers the products your clients use on their pets and in their homes. Permethrin — safe in dogs, potentially fatal in cats, the glucuronidation explanation, IV lipid emulsion therapy. Fipronil — low toxicity profile when used appropriately, the GABA receptor mechanism, seizure risk in rabbits. Imidacloprid — generally safe, GI signs with oral dosing. Organophosphates — SLUDDE signs, atropine as antidote, pralidoxime chloride. Selamectin and ivermectin — the MDR1 mutation picture, clinical signs that can last days to weeks, lipid therapy and mechanical ventilation in severe cases.

The outdoor hazards chapter closes the e-book with ethylene glycol — one of the most important toxicology topics in small animal medicine and one of the most time-sensitive. Dr. Hemmelgarn covers the three clinical phases, the diagnostic changes including metabolic acidosis, elevated serum osmolality, isosthenuria, calcium oxalate crystalluria, and azotemia, the benchtop test limitations in cats, and the treatment decision between fomepizole and ethanol. The prognosis discussion is honest: if renal failure is already present when treatment begins, the outcome is very poor. The earlier the presentation and the faster the intervention, the better the chance.

Herbicide toxicity, compost hazards, mushroom toxicity — hepatotoxic, neurotoxic, muscarinic, hallucinogenic, and nephrotoxic species covered with clinical staging and treatment — round out the final chapter.

Why This E-Book Is Different

There is no shortage of toxicology information in veterinary medicine. The ASPCA Animal Poison Control Center hotline exists. Plumb's has drug information. VIN has case discussions.

What has been harder to find in a single, free, well-organized resource is the kind of clinical thinking that Dr. Hemmelgarn brings to this e-book — the mechanism explained in terms that make the clinical signs predictable, the treatment organized around what actually has to happen first, and the species differences flagged in the places where getting them wrong changes everything.

This is not a reference you look up after the case. This is the resource you read before the cases start coming so that when they do, the framework is already there.

Get Your Free Copy

The Essentials of Veterinary Toxicology is free for all Vet Candy members. Download it now at myvetcandy.com and add it to your clinical library today.

The call is coming. Be ready for it.