Our companion animals can be poisoned by swallowing solids or liquids, breathing in toxic gases, or absorbing liquid toxins through their skin. Most of the poisons our pets get exposed to are products we use daily and can be found in food, medications, household and garden substances, e.g., human medications and pest control products. Take special care to keep these toxins out of your pet’s reach and pet-proof your house! Established from our experience as a clinic, here are the most common toxins that we encounter on a regular basis.
What are the common causes of poisoning in pets?
1) Ibuprofen (Anti-inflammatory medication)
Giving human medication to pets for pain relief is one of the most common causes of poisoning. Ibuprofen is one of the most common non-sterpoidal anti-inflammatory drug (NSAID) used in humans. This drug causes stomach ulcers in pets. Never give human medication to pets unless instructed by your veterinarian.
2) Paracetamol - Acetaminophen (Anti-inflammatory medication)
In overdose, paracetamol cannot be broken down safely and toxins quickly build up to dangerous levels.
3) Slug pellets
The most common active ingredient in slug pellets is metaldehyde. Slug pellets are attractive to dogs. The slug pellets make dogs wander around the home compound hovering up pellets from treated areas. The poison causes excitement and seizures followed by depression and collapse. Avoidance of the use of chemicals in gardens with pets is important or the pets should be confined indoors or treated areas fence off.
4) Mouse and Rat poisons (Rodenticides/Pesticides)
Pets get poisoned by eating dead or dying rodents. Animals remain well for several days after eating the bait as the poison takes effect. Repeated small doses are more toxic than a single large dose. Signs include depression, weakness, breathing problems, and prolonged bleeding from any minor wounds or abrasions. Poisoned animals can bleed to death without treatment.
5) Cannabis and essential oils
Dogs quite commonly eat cannabis, and although they can show signs of toxicity for several days, it rarely causes serious side effects. Most affected dogs become excited and may salivate a lot. Sometimes affected pets will seem disorientated and may hallucinate - just as in people, the appetite may be increased.
6) Foodstuffs (Raisins, Grapes, Onions and Chocolate)
Pets can be poisoned by human foodstuffs and these poisonings can be fatal. Raisins (and sultanas, currants, and grapes) cause damage to the kidneys, chocolate poisoning affects the brain and the heart, and onion poisoning can cause anaemia. In animals that are susceptible to these poisonings, even a small amount (a piece of fruit cake, a few squares of dark chocolate) can have serious effects.
7) Adder bites
Snake bites are most common in warm weather when the snakes are active. Dogs can become unwell very quickly after an adder bite with pain and progressive local swelling. Treatment often includes the administration of antivenom. The adders include Puff adder (Bitis arietans), Sand adder (Bitis peringueyi) and Common European adder (Vipera berus)
8) Lilies (Lilium species)
Plant poisonings are more common in cats than in dogs. Unfortunately even a little of this plant is extremely toxic to the kidneys. Prompt treatment is essential in all cases of lily exposure.
9) Anti-freeze (ethylene glycol)
Ethylene glycol is water-soluble and non-volatile and is commonly used as an automobile antifreeze or as a coolant in automobile radiators and air-conditioning systems. Ethylene glycol interferes with the hydrogen bonding network in pure water. Water freezes at 0°C and pure ethylene glycol at -12°C, but a mixture of the two freezes at a much lower temperature – the lowest freezing point reached is -55°C in mixtures containing 70% ethylene glycol. Ethylene glycol is one of the most common poisonings in dogs and cats because it is highly palatable, drunk willingly, especially if no other water sources are available. Clinical signs include vomiting, ataxia (wobbly gait), polydipsia (excessive drinking of water). Treatment involves the administration of ethanol 20% for 48 - 60 hours, supportive fluid therapy, Sodium bicarbonate, or 4-methyl pyrazole.
10) Toad poisoning
Most toads are relatively harmless but all toads have glands in their skin that secrete unpleasant substances. Animals that have put toads in their mouth show excessive salivation and may paw at their mouth. Usually, the signs resolve without treatment (pets may appreciate having their mouth washed out with a hose). In more severe poisonings signs include weakness, limb swelling, and seizures.
Chocolate contains caffeine, and a chemical called theobromine. These two ingredients can be toxic to pets, especially dogs and cases of chocolate poisoning in dogs are common when chocolate and chocolate products are readily available in the home, eg Christmas, Valentine's Day and Easter. The clinical signs can range from a simple stomach upset to life-threatening problems, depending on how much chocolate is ingested. Dark chocolate and baking chocolate are more toxic than white chocolate.
12) Xylitol (sugar-free gum & more)
Xylitol is a 5-carbon sugar alcohol that is used as an artificial sweetener in sugar-free chewing gums and confectionery, and as a sugar substitute in baking. It is also an excipient in many human and veterinary medicines. In certain instances, it is used in some drinking water additives for animals to decrease dental plaque and calculus formation. Xylitol is a potent stimulator of insulin release in dogs and clinical signs include vomiting, lethargy, drowsiness, Weakness, wobbling, collapse, coma, convulsions, tachycardia (increased heart rate), hypotension, haemorrhages (bleeding) of the oral mucosa, melena (blood in stool), liver failure and hypoglycaemia (low blood sugar). The onset is often within one hour, though it can be delayed.
13) Antidepressant Medications
Antidepressant medications increase the activity of chemicals called neurotransmitters in the brain. Increasing the activity of the neurotransmitters serotonin, norepinephrine and dopamine seems to relieve or prevent the symptoms of psychological depression and anxiety.
14) Vitamin D3 (Cholecalciferol) Overdose
Cholecalciferol (vitamin D3) is used both as a dietary supplement and a rodenticide. Vitamin D3 poisoning is caused by the consumption of baits in rodenticides, e.g. rat poison, poisoned wildlife, or when ingested as a technical grade agent. Most rodenticide baits contain 0.075% cholecalciferol. Ingestion of human medications containing vitamin D or over-supplementation with Vitamin D via the diet also causes toxicosis, especially suckling puppies if the dam is over-supplemented.
Cholecalciferol poisoning is characterized by phosphate and calcium levels in circulating blood, leading to kidney failure, heart abnormalities, hypertension, depression, lack of appetite, vomiting, diarrhoea, and lethargy. The increased calcium and phosphorus leads to calcification of soft tissue, especially the highly vascular areas of kidneys and lungs, as well as within the walls of the great blood vessels. Clinical signs usually develop within 12 – 36 hours of ingestion and the initial signs can include depression, lack of appetite, excessive urination, and excessive drinking of water.
15) Stimulant Medications (e.g., for ADD/ADHD)
ADD/ADHD refers to Attention Deficit Disorder (ADD) and Attention-Deficit/Hyperactivity Disorder (ADHD) respectively. Stimulants are an effective way of managing ADHD symptoms in humans such as short attention span, impulsive behaviour, and hyperactivity. There are many stimulants available: short-acting (immediate-release), intermediate-acting, and long-acting forms. Stimulant therapy is the most commonly used treatment for Attention-Deficit Disorder/ Hyperactivity Disorder (ADHD). Examples of ADD/ADHD drugs include the following:-
Adderall XR (amphetamine)
Focalin XR (dexmethylphenidate)
Quillivant XR (methylphenidate)
Strattera (atomoxetine hydrochloride)
Vyvanse (lisdexamfetamine dimesylate)
ADHD is not usually diagnosed in pets. Pets who have access to these medications, a small amount gets them poisoned and exhibit the following clinical signs:-
An increase in activity, e.g. pacing, walking in circles, or being unable to sit still.
Heart rate, blood pressure, and body temperature are elevated
In cats, there may be an increase in activity, or they may sit unusually still and stare for long periods of time.
In severe cases, these signs can become life-threatening.
The majority of fertilizers contain varying amounts of nitrogen, phosphorus, and potassium (potash). This is indicated by the three numbers on the packaging (i.e., 30-10-10). Fertilizers may also contain iron, copper, zinc, cobalt, boron, manganese, and molybdenum, some of which may be toxic in large concentrations. Besides, fertilizers may also contain herbicides, pesticides, and fungicides which increase the risk of poisoning. Although small ingestions of fertilizer may only result in mild stomach upset, larger ingestions can result in severe poisoning from iron, nitrogen, and other chemicals or form a concretion in the stomach resulting in a bowel obstruction or severe and painful inflammation of the pancreas (pancreatitis).
Spot-on flea/tick medication for dogs
Canines and felines have different physiologies when it comes to the use of products that control ticks and fleas and they affect them differently. Canine formulations of flea and tick prevention can be fatal for cats, therefore, do not use the same medication on your dog for your cat -- unless it has been specifically formulated for both species. Below are examples of the products you cannot use on cats.
The use of household cleaners is perhaps the most serious exposure to modern household cleaners, which may contain a number of proven and suspect causes of cancer. Cleaning products with ingredients such as bleach, ammonia, chlorine, laundry detergents, glycol ethers, or formaldehyde can put pets at risk for cancer, anemia, liver and kidney damage. Even when the toxic cleaners are put away and closed, the vapors left behind can continue to harm both humans and pets.
What are the clinical signs of a poisoned pet?
Every poison produces different effects and the clinical signs of a poisoned pet include the following:-
Restlessness or drowsiness
Vomiting or diarrhoea
Salivation or drooling from the mouth
Muscle tremors, twitching, or seizures
Confusion, changes in behaviour, or an abnormal reaction to sound or light
8. Wobbly gait (ataxia)
9. Changes in gum colour to blue, pale, or even very red
10. Unusual odours or smells (either on the breath or from contamination on the skin)
11. Bite marks - (poison can result from a bite or a sting)
12. Burns to the mouth or the tongue
13. Irritation or inflammation of the skin
14. Foreign material passed in the stools
What needs to be done when a pet is poisoned?
In cases of poisoning, a rapid response is critical and the following should be done:-.
Protect the companion animal by removing him or her from the source of the poison.
If possible, safely remove any suspect material from the animal's mouth
Don't let other people handle the pet (disorientated or frightened animals may become aggressive and other people may be contaminated with the poison)
Provide drinking water that may dilute ingested poisons
5. Take the pet and the suspect material or product to the nearest veterinary clinic in case your veterinarian is far. It is always better to phone in advance to warn the surgery that you are on your way. The sooner a poisoned animal receives treatment, the higher its chances of recovery.
6. If the pet has a toxic substance on its skin or coat, wash it off to reduce further absorption.
7. Protective clothing must be worn and water only should be used to make sure you do not get contaminated in the process.
Is induced vomiting advised in a poisoned pet?
If a pet is already showing signs of poisoning do not attempt to make him or her vomit or drink anything but seek immediate veterinary care. Poisons that have been eaten in the last 2 hours may be possible to remove from the stomach by making the animal vomit. If the pet has swallowed a corrosive or petroleum-based substance, e.g., some solvent-based paints, some toilet cleaners, some drain cleaners, petrol, turpentine substitute (white spirit) do NOT induce vomiting (as these may cause further damage to the throat if the substance is brought up). Instead, wash the mouth and face with water and give milk or water to drink (within 10 minutes of the pet swallowing the substance).
It is only safe to make a pet vomit if he or she:
Is alert or only mildly depressed
Has an intact gag reflex, i.e., gags when fingers are placed at the back of its throat
Is known NOT to have ingested corrosive (caustic) or petroleum-based substance
Never induce vomiting if a pet:
Has already been sick
Is unconscious, very sleepy, or depressed
Has eaten a corrosive (acidic or alkaline) product (highly corrosive products can do more damage if vomited up)
Has eaten a petroleum-based product (volatile products can do more damage if vomited up)
Do not try to make a dog vomit (unless specifically instructed to do so by a veterinarian), particularly if the agent or timing of exposure is uncertain. If you are able to make your dog vomit or it has already vomited, collect a sample and take it to the veterinarian in case it is required for the identification of possible intoxicant.
Never give saltwater to make a dog vomit; this is potentially very dangerous and can cause salt poisoning. Washing soda can be used on the advice of a veterinarian - give as big a piece as it is possible to get down the animal's throat. Place the crystal over the back of the pet's tongue so that it is swallowed. The pet should vomit within 5 minutes - if not, repeat this once. If the pet does not vomit, do not keep giving further doses as soda crystals can themselves be poisonous.
Note: It is essential to use washing soda (soda crystals) and not caustic soda (sodium hydroxide) as this is very corrosive and will cause serious injury. If there is any doubt - do not make the dog vomit.
What information will be of help to a veterinarian?
On arrival at the veterinary practice, the pet will be assessed immediately to make sure that its condition is stable before any other treatments are instigated. The veterinarian will want to know:
If the pet has known access to possible poisons
If so what poison?
Is a sample or container available?
When did the pet have access to the poison (how long ago)?
How much was eaten or drunk (how much is missing from the container)?
Has the pet shown any signs of being unwell?
Is the pet receiving any medication or has any pre-existing medical conditions?
Taking a sample of the poison or any packaging associated with it may help the veterinarian to provide the best care for your pet.
How is pet poisoning prevented?
Almost all cases of poisoning are accidental. Therefore, the best way to prevent poisoning is to ensure that all poisons are kept out of sight and reach of the pets (and children):
Dispose of all unwanted medicines safely.
Read the product label and follow the instructions for correct use.
Ensure lids are replaced correctly to prevent spillage if the container is knocked over.
Clean up drips and spills promptly.
Dispose of empty containers and waste food safely.
Put pest control products in pet-proof containers before putting them out.
Be vigilant when walking a dog to ensure it does not pick up any unusual things.
Younger animals are more likely to be affected as often chew strange objects. Cats are less likely to be poisoned than dogs as they are naturally more suspicious of novel substances. Cats may be poisoned by licking off substances spilt on, or applied to, their coat.
Here is a summary video of pet poisoning https://fb.watch/bLdW0eFUh1/
Gaynor A R et al (1999) Acute Ethylene Glycol Intoxication. Part II. Diagnosis, Treatment, Prognosis and Prevention. Comp Contin Educ Pract Vet 21 (12), 1124-1133 VetMedResource.
Thrall M A et al (1998) Advances in therapy for antifreeze poisoning. Calif Vet 52, 18-22.
Murphy M J (1994) Toxin exposure in dogs and cats - drugs and household products. JAVMA 205 (4), 557-560 VetMedResource.
Crisp M S et al (1989) Peritoneal dialysis in dogs and cats - 27 cases (1976-1987). JAVMA 195 (9), 1262-1266 PubMed.
Kore AM, Kiesche-Nesselrodt A. Toxicology of household cleaning products and disinfectants. Vet Clin North Am Small Anim Pract. 1990 Mar;20(2):525-37. doi: 10.1016/s0195-5616(90)50043-1. PMID: 2180194.
ASPCA Animal Poison Control Center: www.aspca.org/pet-care/animal-poison-control, telephone (888) 426-4435.
Veterinary Poisons Information Service (VPIS); www.vpisglobal.com, telephone + 44 (0) 2073 055 055.
8 Common Household Chemicals Harming your Pets, & their Non-Toxic Alternatives: www.eartheasy.com/connect/