Human Foods That Are Toxic To Your Cats And Dogs

Domesticated cats and dogs, although still genetically linked to their feral ancestors, depend entirely on us for their food. The keen and instinctive senses they used in the wild to successfully hunt prey for daily survival have been diminished as we offer them comfort and security in our homes. Nevertheless, their digestive systems and nutritional requirements are still designed for their inner “wild beasts”, and it is important for us to remember this when we offer them food.

Dogs are classified as omnivores, with a preference for meat. Their wild ancestors sometimes ingested plant matter (most of it found inside the prey they were eating), and they would forage and scavenge during difficult times, eating whatever they could (berries, fruit, vegetables) when necessary to survive.

Cats are classified as obligate carnivores—animals which must eat meat to live. Our feline pets’ ancestors were also designed as hunters; cats can swallow whole, small prey, feathers and bones intact, and expel the non-essentials later.

Cats and dogs have fang teeth, which helped their feral relatives tear and scrape large pieces of meat from the bones of their prey. They have molars to crush food and bone as needed, but they cannot move their jaws from side to side as a human can, and really gulp down their food quickly and in large pieces. Cats and dogs don’t have digestive enzymes in their saliva—the work begins in their stomachs, which have a much higher level of acidity than ours do.

Do our pets enjoy food the same way we do?


Cats and dogs have a much less developed sense of taste than humans. Humans have approximately 9,000 taste buds on their tongues–dogs have roughly 1700, and cats fewer than 500 (and, according to recent research, cats are missing the receptors required to taste “sweet”).

Humans who find it no longer necessary to hunt for food in the wild can take time to sit down, sometimes in a social setting, and enjoy their food over a period of hours.  Cats and dogs are not social diners, and belong to one of two basic groups:

  • those who display territorial attributes at meals, tending to eat like it may be their last meal for a while—quickly, and often indiscriminately, trying to satiate

themselves on whatever is in front of them

  • Picky or finicky eaters, who push their food around in their bowls, spit it out, or refuse entirely what is offered

Work with territorial eaters to ensure that they are calm at meal times—do not allow them to jump, growl, or display hostility to other pets or family members.

Fussy eaters may just not like what is offered, have delicate tummies, or may be very smart animals who have come to understand that refusal of food brings something tastier to their bowls!

Any sudden change in eating patterns should be watched carefully, as it can be an early warning sign of physical or emotional ill health.

Dogs can sometimes eat rotting, putrid meat without getting ill (not necessarily on a regular basis, but certainly in order to survive in difficult times), and can even have an unpleasant experience with something that made them ill, and within 24 hours forget the experience and eat the same thing again. Here cats seem to have the upper paw, and will learn to avoid the offending food, at least for a little while.

If it’s good for me, it’s good for my cat and dog

Again, no!  At least, not necessarily.

As we have domesticated animals for companionship, we sometimes tend to “humanize” their needs. If my diet is healthy for me, shouldn’t it be fine for my pet, too?

It’s really important to remember that:

  • even though they are part of our family, our pets are not our children; their daily nutrition must be based on their requirements as animals
  • even if I am eating a first-rate diet myself, the individual foods I consume may not only not be advisable to feed to my pets, they may be toxic and even fatal

to them

Obviously, we are not allowing our domesticated cats and dogs to wander daily in search of prey to eat. We are their sole source of nourishment, and we must take the role seriously. We can contribute to their good health and longevity not only by offering them the best quality food possible, but also by understanding what not to feed them and why.

Food and drink on the “Never Feed List”

  • Alcoholic Beverages

    Animals suffering from alcohol poisoning can stagger while trying to walk, lose their balance, and have their breathing rate slowed to the point of non-responsiveness. Cats and dogs can suffer seizures and severe and permanent brain damage from a sudden drop in blood sugar and, depending on the size of the animal and the quantity of alcohol ingested, become comatose and die.

    Remember as well, animals do not have to be “fed” in order to ingest a poison. Alcoholic beverages left open in containers and glasses can be lapped up by your pet. Seemingly innocuous items like toothpaste or mouthwash can also contain enough alcohol content as to prove dangerous or intoxicating to your pet.

  • Hops

    Home brewers take note! Ingestion of hops can trigger a condition called malignant hyperthermia in dogs, causing a rapid and extreme rise in core temperature. Symptoms include nervousness, rapid heart rate, excessive panting, and fever, and can lead to complete renal failure and death. Unused hops, sediment waste, or any left-over from the brewing process should be cleaned up immediately and discarded safely and securely.

  • Avocados

    The fruit contains a compound called persin, which can cause vomiting and diarrhea in cats and dogs. This compound is found in the skin, pits, leaves, and fruit of the avocado, so make sure to discard these elements safely and securely when you prepare the fruit in your kitchen. Your pets should never be able to scavenge through the household garbage when you are not around!

    Something else to consider—if you have a garden and are growing avocados, make sure your pets cannot get to the fruit outdoors.

  • Table scraps

    Highly seasoned “human meals”, salted foods, and fatty meat scraps should not be fed to your pets. It is never a good idea to allow your pets to jump on the table in search of their meals or sit anxiously at your feet waiting for supper. Spicy and salty foods can cause problems with digestion, increased blood pressure, increased heart rate, vomiting, diarrhea, excessive thirst, excessive panting, and dehydration. Sometimes a table scrap can contain bones which can splinter, causing lacerations along the digestive tract, or become lodged and obstruct your pet’s ability to breathe. Fatty foods can cause your pet to develop pancreatitis, and if these scraps are in addition to their daily diets, can lead to diabetes, arthritis, and obesity.

    The occasional scrap of food may not be harmful, but if you feed your pets their required nutrients daily, why bother? Better to compost your food waste when possible, and discard the rest in a secure garbage can.

  • Fish and Milk

    Contrary to many people’s beliefs, milk and fish are not necessarily good for your cats and dogs. Adult pets may be lactose intolerant, and ingestion of milk and cream may cause tummy distress, with vomiting and diarrhea.

    Although fish is considered a healthy protein, too much fish in a diet can be a problem. Depending on the species of fish and its source, it may be contaminated with mercury, lead, or other heavy metals or pollutants. If the pet owner is an adherent of the raw food diet for pets, fish contaminated with bacteria or parasites can prove fatal in a very short period of time. Signs to watch out for include vomiting, swollen lymph nodes, and fever. Depending on the parasite, even serving properly cooked fish may not eliminate this problem.

  • Raw Yeast Dough

    If your pets love to sit in the kitchen and watch you bake, don’t offer them leftovers of your raw yeast dough. Yeast is a living organism that causes your baked goods to rise—and this expansion is exactly what will happen in your pet’s stomach. Distention, bloating, tummy distress, and finally, as the fermentation process continues, alcohol poisoning can cause all kinds of terrible pain for your pets.

  • Onions, Garlic and Chives

    Onions, garlic, and chives contain sulfoxides and disulfides, which can, in large doses, prove toxic to cats (particularly) and dogs, and can lead to problems starting with upset tummies and ending with hemolytic anemia. Onions (in all forms—powdered, raw, cooked, in table scraps, sauces, and even in baby food) are the most toxic of the trio—even small, repeated doses can cause the same damage as one large dose and should be avoided as much as possible.

    While small amounts of garlic (found in many high-quality pet foods or offered as a dietary supplement) are considered safe, beneficial to health, and recommended as a natural flea repellant and immune-system booster, you may want to discuss dosage requirements for your particular pet with your veterinarian.    

  • Macadamia Nuts

    An unknown agent present in both raw and roasted macadamia nuts is toxic to pets. Symptoms of poisoning include tremors, inability to stand, and weakness or even paralysis in the legs.

    Macadamia nuts are toxic in all forms—in baked goods, butters, and oils. Very small quantities of nuts can cause very serious problems.

  • Fruit Pips and Pits

    The pips or pits of pears, cherries, peaches, apricots, plums, persimmons, and apples contain cyanide, and ingestion can cause cyanide poisoning in your pets. Symptoms include dilated pupils, nervousness, trouble breathing, and rapid heartbeat, and can lead to coma and death. The pit itself can splinter and cause lacerations in the digestive tract or obstruct your pet’s airways or digestive system.

  • Raw (or Green) Potatoes, Tomatoes, and Rhubarb

    The toxins here are solanine and tomatine, which cause upset tummies, dizziness, vomiting, diarrhea, and cardiac dysrhythmia; and oxalates, which can trigger kidney problems, as well as digestive and heart dysfunction.

  • Mushrooms

    Detecting which mushrooms are toxic to your pets is a very difficult job. While some mushrooms are perfectly harmless, others can prove fatal. If you are not a mycologist, it’s best to consider all mushrooms as dangerous to your pets. You don’t have to go to the forest either— those white fungi that pop up on your lawn should never be ingested by your pets. Symptoms include bloody diarrhea, vomiting, rapid heartbeat, and fever; which may progress rapidly to seizures, coma, and even death.

  • Chocolate

    The offending agent in chocolate seems to be the alkaloid known as theobromine, which dogs metabolize slowly. This acts as a stimulant in the body, contributing to a rapid heart rate, vomiting, nervousness, and increased thirst and urination. If left untreated, theobromine poisoning can lead to tremors and seizures that can prove fatal.

    The darker the chocolate the more dangerous it is. Unsweetened baker’s chocolate has the highest amount of theobromine, followed by semi-sweet, milk chocolate, and white chocolate (not a true chocolate).

  • Caffeine (found in coffee, tea, chocolate, soda)

    Caffeine poisoning can manifest with symptoms of rapid breathing, heart palpitations, tremors, and bleeding, and there is no treatment. Apart from the substances listed in the heading, caffeine can also be added to energy drinks, cold remedies, and pain killers.

    If you use coffee grinds as fertilizer, make sure your pets can’t get near the plants or pots.

  • Grapes, Raisins, and Currants

    The actual toxin is still unknown, but ingestion of grapes, raisins, or currants can cause vomiting, lethargy, and a cessation of drinking and urinating, leading up to complete kidney failure. If you suspect your pet has been poisoned, or if you see pieces of grapes or raisins in his stool, seek emergency medical care.

  • Xylitol

    This product is a sugar substitute, extracted from the fibres of fruits and vegetables. Xylitol is a sweetener (safe for human diabetics) found in many obvious foods (low-cal or diet meals, candies, and baked goods) and many foods and products you may not have considered (toothpaste, mouthwash, and gum).

    Some symptoms of Xylitol poisoning in pets are vomiting, weakness, and difficulty in coordination. Xylitol can trigger the sudden release of a large amount of insulin in your pet, causing low blood sugar, leading to seizures, coma, and liver dysfunction or even complete failure.

  • Raw Meat and Eggs

    Raw meat and eggs have the potential to carry some very serious bacteria, such as Salmonella, E. coli, Staphylococcus Aureus, and Clostridia, which can sicken your pet, the person preparing the food, and people coming into contact with you or your pet.

    However, many people feel that a raw food diet is beneficial to their pet’s well-being, helping their animals stay healthy and strong, reducing or even eliminating chronic health issues, such as diabetes, allergies, and digestive problems.

    If you choose to offer your pet a raw food diet, you must be extra vigilant to ensure that proper sanitation rules are followed in food preparation, handling, and disposal.

In the Terrible Event of an Emergency

If you noticed your pet eating something suspect, or if your pet begins acting strangely, you must act quickly. Remain calm, call your veterinarian immediately, and be prepared to follow your doctor’s instructions.

Try to have information on:

  • what was ingested and the quantity
  • when it was ingested
  • any symptoms or unusual behaviour manifesting

If your pet vomited or excreted loose, bloody, or foul-smelling feces, try to collect a sample in a plastic bag and take it with you to the vet for analysis.

Be Proactive!

When you first bring your pet home to begin a new life with you, make sure to ask your vet for a 24-hour emergency number if available. If not, ask for a recommendation to an emergency clinic in your area. Before an emergency happens, find out where the clinic is located by taking a drive there during daylight hours while you are calm. This half hour of planning and preparation may one day save your pet’s life.