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sick dog with poison sign

Symptoms and Signs of Poisoning in Dogs (And What To Do)

A poisoned dog can be a serious, and even fatal, condition. Here are signs and symptoms that indicate poisoning in a dog.

While pet owners may be extremely diligent in caring for their dogs and trying to keep them safe, sometimes accidents happen or dogs get into things they shouldn’t. We also hear about scary scenarios in which someone intentionally hurts a dog with a harmful treat or a toxic substance. 

Suspecting that your dog has ingested something that they shouldn’t and being unsure of the consequences can be very distressing. But knowing what signs and symptoms to look for, as well as understanding what steps to take in response, can make such situations easier to manage.

What Should I Do If My Dog Is Poisoned?

If you know or suspect that your dog has ingested, inhaled, or otherwise come into contact with foods or other substances that are toxic to dogs, you should contact your veterinarian immediately. If the incident occurs outside of your vet’s office hours, try to find an emergency clinic or call an animal poisoning helpline. 

Services like the ASPCA Animal Poison Control Center—which charges a fee of $75 and can be reached 24/7 at (888)426-4435—can assist with medical advice as a first step or if the incident occurs outside of your vet’s hours. We have used the service a number of times, and while we had one long wait time (not what you want during an emergency), our experiences have been generally good.

A similar service available is Pet Poison Helpline — (855) 764-7661 — which also charges $75 for a phone consult. We have not used this service but have heard positive reviews from others.

No matter how you seek care for your dog, you should try to bring a sample of the poisonous substance or its packaging (if possible). If you know what the harmful substance is, make sure your dog cannot get to more of it in the meanwhile. 

How Quickly Do Symptoms of Poisoning Appear?

Unfortunately, poisoning symptoms do not always appear quickly, which is part of the reason why it is crucial to get to your vet or contact pet poison control as soon as you know or suspect that your dog has ingested something toxic. 

Some toxins may affect a dog very rapidly, while others may cause symptoms that only appear after regular exposure; additionally, a dog’s health status, size, and age may affect how soon the symptoms show up.

puppy showing poisoning symptoms

Signs and Symptoms of Poisoning in Dogs

The symptoms of poisoning are varied and depend on the substance that caused them. 

Sometimes the symptoms relate to how the dog came into contact with the toxin in question, which can provide some clues to the cause if you aren’t sure what has happened to your dog. For instance, a dog who has walked through or rubbed against poisonous plants may experience signs of skin irritation, while a dog who has eaten a poisonous plant is more likely to experience symptoms such as foaming at the mouth or vomiting. 

The symptoms are not always directly indicative of how the dog came into contact with a noxious substance, but a description of the symptoms can still be very useful for vets and helpline representatives.

Here are some common signs of poisoning in dog:

(Note: all of these symptoms can be indicative of other medical issues in addition to poisoning; if any are present, you should consult with your vet regardless of whether you believe them to be caused by poisoning or not.)

  • Nausea, Vomiting, Diarrhea, or Decreased Appetite. Symptoms like these are very common in cases of poisoning, especially when the substance in question has been ingested. Because dogs do sometimes vomit without a clear cause, it is important to be familiar with your dog’s usual routine so you will be able to tell if the vomiting is out of the ordinary. If the vomiting is sudden, try to check to make sure it wasn’t caused by unknown or toxic substances.  
  • Convulsions, Muscle Spasms, or Seizures. These symptoms are usually caused by toxins that affect the nervous system or muscles. If you see your dog unexplainably convulsing, having muscle spasms while not asleep, or experiencing a seizure (without a prior history of seizures), you should check around the area to see if they have gotten into anything they shouldn’t have, especially substances like alcohol, medications, or toxic plants. 
  • Difficulty Breathing or Heavy Panting. Although dogs can have certain health problems that cause difficulty breathing, respiratory symptoms can also be a sign that they have come into contact with a toxic food, such as avocados, grapes or raisins, onions or garlic, or the sweetener xylitol. Difficulty breathing can also be a sign of contact with certain poisons, including some rodenticides or medications (both human and animal) not intended for the dog. 

Heavy panting is a natural stress response in dogs, but it can also be a sign of a problem like heatstroke. It is also possible for dogs to heavily pant after eating something toxic, including chocolate, antifreeze, slug pellets, or rat poison.

  • Discolored Gums. If you believe your dog may have ingested something harmful, it’s a good idea to check their gums. Healthy dogs’ gums are naturally a bubblegum-pink color (certain breeds may also have black spots on their gums), but when a dog has ingested something it shouldn’t have, its gums may turn pale (in the case of rat poison) or other colors, such as bright red (in the case of cyanide, such as from a cherry pit). 
  • Drooling or foaming at the mouth. Foaming at the mouth or excessive drooling may be a sign that your dog has eaten a poisonous plant or a toxic chemical. 
  • Hypothermia or Fever. Healthy dogs tend to have temperatures between 101 and 102.5˚ F. dogs experiencing hypothermia have temperatures under 99˚ F, while dogs experiencing a fever have temperatures over 103˚. Dogs who have been poisoned may experience more extreme body temperatures, so it is not a bad idea to check your dog’s temperature if you are able to (preferably with a rectal thermometer because they tend to be more accurate). 
  • Increased Urination. Because some poisons and toxins can damage the kidneys (even potentially causing kidney failure), an affected dog may experience an increased need to urinate. In the case of antifreeze poisoning, the dog may also void less each time despite needing to urinate more often. 
  • Skin Irritation or Swelling. Some toxins that a dog may come into contact with—including those from plants and certain chemicals—could irritate or burn its skin. Swelling may be related to skin irritation, or it may be due to the ingestion of a toxic substance. Additionally, swelling could be due to incidents such as snake bites or insect stings.
  • Lethargy. It is not surprising that dogs—like humans—can end up feeling really worn out or lethargic when they are sick, but this can also be a symptom of poisoning. In some cases, it may be a sign of exposure to a substance such as rat poison, which can cause internal bleeding that leads to lethargy. 
  • Collapse. Some substances are so harmful to dogs that they may cause the dog to collapse before other symptoms appear; these include certain chemicals and plants, prescription medications, illicit drugs, and snake bites. 

It is also quite possible for dogs to die from poisoning and, depending on the toxin, have that occur fairly rapidly. Because of this risk, it is crucial that you call a helpline or contact your vet as soon as possible when you witness these symptoms or see a dog get into something poisonous. 

The long-term manifestations of poisoning in dogs tend to be related to organ damage. These include conditions affecting the brain, heart, kidneys, or liver. 

lethargic dog

Ways to Prevent Poisoning in Dogs

Although it is impossible to completely eradicate the chance that your dog may come into contact with a toxic substance, you can take steps to ensure that your pooch will be safe from the more common toxins.  

First off, be careful with the “human foods” you share with your pooch. If you aren’t sure whether or not a dog can eat a certain food, it is better to either look up safety information or simply abstain from giving them any.

Also, just because a food or substance is not considered toxic to dogs does not automatically mean they should eat it; while it’s fun to give your dog treats, there are plenty of treat options made specifically for canines. Though it may feel as though your dog is trying to make you feel bad for not giving them just a nibble of your food, they will be perfectly fine without it.

It is also important to be aware of things that might be harmful in your dog’s environment. For instance, plants like oleander, tulips, and sago palms are toxic to dogs and would be good to avoid planting in your yard. Additionally, if you take your dog to the beach, do not allow them to eat any of the seaweed that washes up on the shore (unseasoned, processed seaweed is an okay snack for dogs, though).

Finally, be very careful with chemicals around the house and yard, including car fluids and insecticides. Try to use cleaners and pesticides that will not hurt your pets, and quickly clean up spills and outdoor chemicals, including car fluids such as antifreeze (which, unfortunately, actually has a taste that is very appealing to most dogs). If you ever feel like a chemical is aggravating your breathing, get yourself to fresh air and bring your dog with you—they will likely feel better, too. 


If you see your dog eat something they shouldn’t or are worried that might have happened, it does not hurt to contact your vet or a pet poison helpline, especially because poisoning can be extremely damaging—if not fatal—to your pup.

By staying vigilant for signs of discomfort and keeping as safe of a home and yard environment as you can, you can help your dog remain safe and healthy.

Chelsea Dickan

Chelsea Dickan

Chelsea Dickan is a long-time advocate for animals, especially those that bark or meow. When she isn't writing, she enjoys reading and watching scary movies in which the dog doesn't die.