6 Deadly Poisons That Could Kill Your Dog
Quick Answer: The top three household poisons that can be deadly to dogs are antifreeze, rodenticide, and human medications. If you suspect your dog has ingested any of these, call your veterinarian or a pet poison control center immediately.
Deadly Poisons for Dogs
Poisoning is a common (and potentially expensive) reason why dog owners visit their veterinarians or emergency clinic. I want to give my PetPlace readers the information they need to make sure that they are aware of common household toxins for dogs.
Here are 6 Deadly Poisons That Could Kill Your Dog:
#1 – Antifreeze.
This is the most common deadly poison ingested by dogs and cats. As little as one teaspoon can kill a small dog. Antifreeze has a sweet taste and dogs like it. Please make sure to keep ALL antifreeze away from your dog.
Common Products: Prestone®, Peak®, and Zerex® antifreeze/coolants
Found In: Car radiators, winter windshield de-icers, some HVAC systems
Prevention Tips:
- Store antifreeze in sealed containers, well out of pet reach.
- Clean spills immediately—dogs are attracted to its sweet taste.
- Choose pet-safe alternatives like propylene glycol–based antifreeze labeled "low-toxicity" or "pet-safe."
#2. Mouse and Rat Baits.
Is rat poison deadly for dogs? Absolutely!
There are several ingredients in mouse and rat bait products that are toxic. The most common one causes bleeding disorders that can be fatal. Make sure any baits you use are out of your pet’s reach.
Common Ingredients: Warfarin, bromethalin, cholecalciferol, zinc phosphide
Common Products: D-Con®, Tomcat®, Havoc®, Just One Bite®
Prevention Tips:
- Avoid using rodenticides in pet-accessible areas, even crawlspaces or garages.
- Choose pet-safe traps or professional pest control instead of poison.
- Educate house guests or tenants about the risks if they might use rodenticide.
#3. Slug Bait.
In the summer months, slugs come out and bait is used to kill them. The active ingredient in slug bait is metaldehyde, and it can cause uncontrollable seizures in pets.
Common Ingredients: Metaldehyde (highly toxic)
Common Products: Deadline®, Corry’s®, Ortho Bug-Geta®
Prevention Tips:
- Skip traditional slug bait altogether—opt for pet-safe deterrents like copper tape, diatomaceous earth, or beer traps.
- Keep pets out of gardens treated with any type of chemical slug bait.
- Check mulch and soil amendments for hidden pesticides.
#4. Dog Medications.
Overdosing or accidental access to pet medications is a common cause of poisoning in dogs. If your pet accidentally gets anything they shouldn’t, call your veterinarian. Early identification and treatment can save their life if caught quickly. If the medication is dangerous enough, your vet may even recommend that you induce vomiting to get it out of their system quickly.
Common Culprits: Carprofen (Rimadyl®), Deracoxib (Deramaxx®), Tramadol, and heartworm meds
Prevention Tips:
- Store pet medications separately from human medications and label them clearly.
- Use a medication log to avoid double-dosing.
- Never share one pet’s prescription with another animal.
#5. Human Medications.
Dogs commonly gain access to human medications. Or they are given these medications by a well-intentioned (but misinformed) owner. Human medication can easily be overdosed, and some human medications are toxic for dogs. PLEASE don’t give your dog any medications without consulting your veterinarian.
Dangerous Types: Ibuprofen (Advil®, Motrin®), Acetaminophen (Tylenol®), antidepressants, ADHD meds, cold & flu remedies
Prevention Tips:
- Store all medications in locked cabinets, not purses, nightstands, or countertops.
- Avoid dropping pills on the floor—dogs may snap them up before you notice.
- Teach children and guests to never give any meds to pets without your knowledge.
#6. Insecticides.
Don’t give your pet anything for fleas or ticks unless it is approved by your veterinarian. Some pets are sensitive to certain medications.
Common Ingredients: Permethrin, pyrethroids, organophosphates
Common Products: Raid®, Ortho Home Defense®, Spectracide®
Prevention Tips:
- Never use products labeled "for dogs only" on cats (and vice versa).
- Apply pest control sprays only when pets are out of the room and keep them away until dry.
- Use natural alternatives or consult a vet before using any pest control near your dog.
Quick Reference: Deadly Poisons and What to Do
| Poison | Toxic Dose | Early Signs | Emergency Action | Vet Prognosis |
| Antifreeze | As little as one teaspoon can be fatal for a small dog | Staggering, vomiting, excessive thirst/urination, lethargy | Call vet or poison control immediately; do not wait | Guarded to poor; prognosis improves with very early treatment |
| Mouse and Rat Baits | Varies by formulation; even small amounts can be fatal | Bleeding, bruising, weakness, coughing, seizures | Seek emergency veterinary care immediately | Variable; better if treated early and specific poison identified |
| Slug Bait | Varies; ingestion of even small amounts can be dangerous | Uncontrollable seizures | Contact vet immediately; do not induce vomiting unless directed | Guarded; rapid treatment is critical |
| Dog Medications | Overdose or accidental access can be toxic | Vomiting, diarrhea, seizures, lethargy | Call vet immediately; may recommend inducing vomiting | Depends on medication and dose; prompt treatment improves outcome |
| Human Medications | One or two pills can be toxic, depending on drug/size of dog | Vomiting, diarrhea, seizures, lethargy, abnormal heart rate | Call vet or poison control right away | Depends on drug and dose; prompt treatment improves outcome |
| Insecticides | Varies; even small exposures can be harmful | Vomiting, diarrhea, seizures, lethargy | Contact vet immediately; do not induce vomiting unless directed | Variable; better if treated early and specific poison identified |
Frequently Asked Questions About Dog Poisoning
How long after ingestion do poisoning symptoms appear in dogs?
It depends on the substance, but symptoms can show up within minutes to a few hours. For example, antifreeze may show signs within 30 minutes, while rodenticides could take 1–2 days before bleeding or bruising appears.
Is it safe to use hydrogen peroxide to induce vomiting at home?
Only under veterinary guidance. Hydrogen peroxide can be dangerous if misused or if the dog ingested a corrosive substance, so call your vet or poison control before attempting this.
Can one pill of human medication really harm my dog?
Yes. Even a single dose of common drugs like ibuprofen, acetaminophen, or antidepressants can be toxic or fatal, especially for small dogs.
What should I have ready before I call the vet or poison control?
Know your dog’s weight, what was ingested, how much, and approximately when it happened. Having the product packaging on hand is also very helpful.
What if I’m not sure what my dog ate but they’re acting strangely?
Always err on the side of caution—contact your vet or a poison control center immediately. Quick action can be lifesaving even when the toxin isn’t yet identified.
I hope these tips will help keep your pet safe. In addition, make sure your dog has the best medical care possible, just in case there is a problem. As you know, I recommend learning about pet insurance. Click here to learn more.