40+ Human Foods and Drinks That Are Poisonous or Unhealthy for Dogs and Cats
Protecting Sylvester, Toto, Dolly, Polly
Several fruits, vegetables, nuts, seeds, condiments, additives, and drugs are toxic to domestic pets.
Some harm only dogs, others only cats, and several are poisonous to both.
Livestock, rodents, lizards, fish, and birds are not immune to the negative effects of certain foods either.
Following is a list of potentially problematic foods that should be kept in a safe place where a curious, inquisitive pet cannot access them and harm itself.
Prevention is key in protecting the health of the animals you love and care about.
Apple seeds contain cyanide compounds capable of poisoning a pet dog or cat if swallowed or chewed (11). Cyanide prevents blood from delivering oxygen to bodily tissues, causing suffocation (26).
Indicators of problems in a pet suspected of eating cyanide-harboring pits, stems or leaves include the development of bright red mucous membranes, enlarged pupils, respiratory distress, fear or nervousness, and signs of shock (6, 7, 17). The condition can be fatal if untreated.
Apricot pits and the stems and leaves of its fruit-producing tree contain the poison cyanide, a potentially fatal toxin to dogs and cats (6, 7).
Symptoms are the same as that for apple seed ingestion (see above). Swallowed whole, pits can also result in a bowel obstruction or blockage, possibly requiring corrective surgery.
Persin, a potentially toxic substance with a fatty acid type structure, is present not just in the avocado pit and surrounding fruit, but in the plant leaves and bark as well (1).
Although harmless to humans unless someone has a persin allergy and, in fact, thought to be beneficial to women suffering from breast cancer (2), persin (and therefore avocados) can be fatal when ingested by domestic pets.
Dogs and cats may be lucky and not have any negative symptoms if given the green fruit; others may vomit, develop diarrhea, or a combination of both (3). However, for some, reactions are much more severe.
Along with other pets, such as rabbits, goats, cattle, sheep, horses, birds and fish, certain dogs and cats experience heart problems, respiratory complications, and ultimately death after ingesting persin-containing foods (4, 26). Symptoms of severe reactions including labored breathing, swelling of the abdomen, and fluid build-up in the chest, abdomen, or area surrounding the heart (7).
In addition to these problems, damage to the mammary gland has also been seen in highly sensitive animals, including in the mouse when it is fed dried avocado leaves (4, 5). Caution should be exercised even by the few with silkworms as pets; avocado plant parts are toxic to these unsuspecting leaf munchers (5).
The cherry pit, like that of the apricot, peach, pear, and plum, contains a form of cyanide (11).
Swallowed whole, intestinal problems may result; swallowed and partially to fully chewed pits can fatally poison dogs and cats (11).
Oranges, lemons, and limes lead to vomiting and diarrhea in dogs (23). Eating grapefruit has the same laxative effect, but is accompanied by the symptoms of light sensitivity and depression (23).
Cats have identical negative effects upon ingesting grapefruit (23).
Bearded dragons benefit from occasional citrus fruit consumption; over-consumption results in nutrient imbalances and possible diarrhea (23).
Cats fed currants can experience kidney damage due to some unknown, yet potent, toxin contained in the berry (17).
Responsible for the deaths of several dogs, grapes and/or raisins in as little as 9 ounce quantities have proven lethal (7). Slightly more fortunate animals may experience kidney damage, requiring emergency medical care, but ultimately surviving (7).
A few very lucky dogs may have no symptoms at all, but since the reason why grapes in their various forms (fresh, dried, fermented) are fatal to some is yet unknown, caution must be taken even if an animal has eaten grapes in the past without incident. This is because toxins may be capable of building up over time and reaching dangerous levels only gradually; a small grape-containing snack here and there may not be problematic on its own, but in combination may prove lethal (8).
If dogs eat a large amounts of grapes or raisins, it is recommended that they are induced to vomit, have their stomachs pumped, and are given activated charcoal and IV fluids (14).
Like dogs, cats can be asymptomatic or else can experience serious kidney damage if fed raisins or grapes (17).
Mistletoe berries are highly toxic to pets; one or two could prove fatal to your dog or cat (14).
The pit of the peach contains cyanide, which is poisonous to dogs and cats.
Symptoms of poisoning are the same as those after eating apple seeds (see above).
Peach pits may be doubly problematic and create an intestinal blockage if eaten or swallowed (1, 17).
The seeds of this fruit are dangerous to dogs and cats and may result in an inflamed small intestine or an intestinal blockage (1)
Plum pits are cyanide-containing, as well as potential hazard if they become lodged in the intestines of dogs or cats (1).
Symptoms of poisoning are the same as those after eating apple seeds (see above).
Oxalates present in the leaves of the rhubarb plants have negative effects on the nervous, digestive, and urinary systems of dogs and cats (18).
Death by broccoli has been seen in different livestock breeds if it comprises more than 25% of the diet; gastrointestinal complications occur when it comprises more than 10% (14).
The problematic substance in broccoli, isothiocyanate, is considred a strong irritant of the digestive system (14).
Chives contain disulfides, as do garlic and onions, damaging the red blood cells of cats and dogs (20). However, onions are more problematic, as they have a much higher disulfide concentration, followed by garlic, and lastly, chives.
The sulfoxides and disulfides contained in garlic, whether fresh, cooked, or powdered can harm red blood cells and cause anemia in both dogs and cats (15).
Signs of anemia include light-colored gums and lethargy (17).
Mushrooms come in many varieties; some are highly toxic, while others are harmless.
Unless an owner is a mushroom expert and can tell the difference, a dog that has been suspected of eating mushrooms should be watched closely. (Mushrooms that sprout in backyards are usually toxic) (15).
To be safe, it is recommended that the dog is induced to vomit and given activated charcoal if the mushroom is not expelled in its entirety (10). The wrong mushroom types can cause jaundice and liver damage, leading to internal bleeding or seizures, or can have hallucinogenic effects resulting in tremors, seizures, and coma (10).
If a dog vomits on its own or develops diarrhea but lacks other symptoms, likely no serious harm has been done; however, if gastrointestinal upset is accompanied by excess saliva or tears, reduced pupil size, slowed heartbeat, depressed activity or lethargy, restlessness, staggering, or a comatose and unresponsive pet, medical care is mandatory (10).
Although cats are less likely to eat mushrooms, they have been shown to be attracted to two poisonous varieties that can kill: the Amanita muscaria and the Amanita pantherina (27). In contrast, dogs are attracted to seven poisonous varieties. One, the Scleroderma species, is also fatal to pigs (27).
Although believed to be safe in small amounts, onions in quantities of a cup or more cause hemolytic anemia in dogs (14). This is because the disulphides contained in onion damage red blood cells (16). All forms of onion are dangerous, whether fresh, cooked, or dehydrated (17).
Cats are more sensitive than dogs to onions and can likely tolerate less (14).
Signs of problems include pale, light-colored gums and lethargy (17). Corticosteroids or immunosuppressants may help an animal suffering from onion-induced anemia (17).
Raw potatoes are laced with glycoalkanoid solamine, a substance that is poisonous to cats (16).
Cooked tubers give no ill effects, but raw potatoes and the stems and leaves of its plant can cause gastrointestinal irritation, bloody stools, lethargy, shaking, paralysis, and heart attack (16, 26).
Tomatoes, as well as the stems and leaves, are poisonous to cats (15). A single small tomato is enough to cause serious gastric and intestinal reactions (15).
POISONOUS NUTS AND SEEDS
The gastrointestinal system of a dog or cat often finds almonds difficult to digest, which can lead to vomiting and other symptoms of irritation (12, 28).
Salted nuts can lead to ion imbalances if eaten in high enough quantities, and may even pose a choking hazard if not chewed before swallowed (28).
Half of all dogs find a chocolate dose of 100mg/kg of body weight lethal (14).
However, lower amounts (as low as 10% of this lethal dose) can cause various levels of poisoning with symptoms such as excited behavior, twitching, frequent urination, and an elevated pulse (14). In some of these cases, resulting heart problems may prove fatal (14).
The problematic substance in chocolate is theobromine, which is lowest in milk chocolate, higher in semi-sweet varieties, and highest in bitter or baking chocolates (14). White chocolate has only trace amounts of theobromine and therefore is not considered a potential poison (16).
However, although white and milk chocolates are the least problematic as far as causing theobromine toxicity, they contain the highest amounts of fat and can cause pancreatitis or enteritis if consumed in large amounts or on a frequent basis (14). These conditions are life-threatening if untreated (14).
Cats, like dogs, are also unable to properly process theobromine and can experience seizures, coma, and death after consumption of chocolate (16).
Chocolate is not just toxic to dogs and cats, but to ferrets as well (9).
Because coffee contains the stimulant caffeine, animals ingesting it may experience overexcited nervous systems (16).
The lethal amount of caffeine for both dogs and cats is 150 mg/kg body weight (28).
Dogs may react after coffee consumption with increases in breathing and heart rate, shaking, and muscle twitching (28). Cats consuming caffeine often experience diarrhea and vomiting, a fast heartbeat, and shake uncontrollably, seize and collapse (16, 17).
A symptomatic animal should be induced to vomit and receive activated charcoal (17).
Hickory nuts cause stomach irritation and can possibly lead to an intestinal obstruction in dogs (12). When moldy, resulting toxins can cause serious neurological problems such as seizures (12).
These nuts contain the organic substance juglone which can bring about laminitis (inflammation of the hooves) if eaten by a horse (12). This substance has no effect on dogs.
Containing more monounsaturated fats than any other seed, macadamia nuts are hard for dogs and cats to digest and can result in problems with the gastrointestinal tract, and in time, lead to pancreatitis (12, 26).
A certain as yet unidentified component in the macadamia nut causes dogs additional complications as well.
As early as 3 to 6 hours after devouring macadamia nuts, this substance brings about drowsiness and a spike in temperature to accompany stomach upset (13). Neurological symptoms usually appear within 12 hours, and dogs will show difficulty moving their hind limbs or standing (13). Most pets recover fully on their own within 24 hours of exposure, but for dogs that recently consumed large quantities of the nut, especially nuts dipped in chocolate, inducing vomiting to limit adverse reactions is recommended (13).
Cats are also poisoned by this unidentified component in macadamia nuts and have digestive, muscular, and nervous system complications upon eating them (17).
The mustard plant and seed is toxic to chickens, cows, sheep, and horses (22).
After eating mustard plant parts, susceptible animals may develop oral irritation, sensitivity to light, labored breathing, and gastrointestinal upset (22). Problems become more severe depending on the quantity ingested. No antidote exists, so animals displaying symptoms should be given medical treatment (22).
Dogs given pecans as a snack can end up with gastrointestinal upset or an obstruction (12). When moldy, pecans cause various neurological symptoms (12).
This is a juglone toxin containing nut, and is therefore linked to laminitis in horses (12).
High in fat, these nuts can cause stomach upset and eventually lead to pancreatitis in dogs and cats (12, 26).
Black walnuts and English walnuts can lead to gastrointestinal problems or a possible intestinal obstruction in dogs; moldy black, English, or Japanese walnuts have strong mycotoxins that cause seizures or other neurological abnormalities (12).
In horses black walnuts can cause the vascular disease laminitis (12). This is due to the toxin they contain known as juglone, which is not problematic to dogs (12).
POISONOUS MEATS AND ANIMAL PRODUCTS
Although not poisonous, a snack of bones is not without potential hazards.
Bones can adhere to the mouth, the throat, or intestines and can splinter and create internal damage or blockages in dogs and cats (15).
A high-fat diet is difficult for the cat or dog system to process and can lead to both obesity and pancreatitis (18, 26).
Large amounts of liver in a dog or cat’s diet can create toxic levels of vitamin A (21, 29). This has a negative effect on bones and may cause deformities, growths, or osteoporosis in cats (21).
In dogs symptoms of toxicity include a calcified skeleton and diseased skin (29).
In some cases, toxic vitamin A levels are fatal (21).
High in both fat and salt, a diet rich in lunch meats can lead to pancreatitis in a dog or cat (25). The high nitrate content in deli meats is also unhealthy (25).
Milk and Dairy
Certain dogs and cats, usually older animals, are unable to process milk products and develop diarrhea after their consumption (17).
If fed any type of fish in large enough quantities dogs develop a deficiency in thiamine (19). Thiamine deficiencies cause anorexia, seizures, and death (17).
Believe it or not, feeding large amounts of canned tuna to a cat can have undesirable effects as well (18). This is because it creates an imbalance of nutrients and may also lead to a thiamine deficiency or mercury poisoning (18, 21).
Eating uncooked eggs can result in unhealthy skin and coats due to the avidin enzyme (18).
This enzyme inhibits the proper absorption of biotin in dogs and cats (18). In addition to avidin-related problems, eggs may be contaminated with bacteria and lead to food poisoning (21).
Raw, uncooked salmon can be infested with flukes that carry rickettsial organisms (14).
These organisms are released in a dog’s intestines and cause fevers within 24 hours, combined with a lack of energy and reduced appetite (14). Four days after consumption vomiting occurs, followed by bloody, loose stool (14).
Fatality rates are as high as ninety percent; hydrating treatments and antibiotics are necessary for survival in most affected pets (14).
Raw fish, similarly to canned tuna, if fed in too high amounts to a cat cause a thiamine deficiency (18). Cats are not susceptible to rickettsial infection via salmon consumption (30).
Improperly cooked meat of all kinds may be contaminated with bacteria, leading to gastrointestinal upset in dogs and cats (18).
POISONOUS CONDIMENTS AND ADDITIVES
Excessive nutmeg consumption can create serious problems for dogs resulting in seizures, tremors, or death (23).
Large quantities of salt dehydrate a pet cat or dog and lead to a sodium ion imbalance (17, 26).
If an animal develops extreme thirst, vomits, or becomes lethargic following substantial salt consumption it may indicate kidney damage (17). Left untreated a pet can develop seizures or fall into a coma and die (17).
To avoid these complications, pets should receive IV fluid treatment (17).
Large amounts of sugar result in overweight pets (cats and dogs) with poor dental health and an increased risk of developing diabetes mellitus (18).
Sugarless xylitol candy
Sugar-free candy containing xylitol is considered dangerous to a pet’s health according to the National Animal Poison Control Center (14).
Not just present in candy, xylitol is found in sugarless chewy vitamins, baked goods, and gums as well. One or two sticks of gum can kill a small dog; three or more sticks can kill a 65-pound pet (15).
Cats are similarly susceptible to xylitol toxicity.
Xylitol causes peaks in insulin and dips in blood sugar, creating a lethargic dog or cat that is unable to retain its balance (15, 21). If untreated, brain damage, liver failure, or blood disorders develop and can lead to coma, seizures, and death (15, 31).
The alcohol present in yeast is absorbed into the bloodstream, resulting in alcohol poisoning (17).
Signs a cat or dog has been poisoned include panting, vomiting, and drooling, followed by coma and eventually death (17, 32). A pet may be saved from the full effects of this by being induced to vomit and receiving activated charcoal and IV fluids (17, 32).
In addition to alcohol poisoning, the dough also causes problems when it expands and creates gases within the warm, moist environment of the body. This leads to gastric or intestinal rupture in dogs or cats (18).
When a dog or cat drinks alcohol it can become intoxicated (19). It takes only two teaspoons of whisky for a 5-pound cat to fall into a coma, and three teaspoons results in death (21).
Hops leads to panting, an elevated heart rate, increases in temperature, seizures, and death in dogs (19). It is also unsafe for cats (26).
Marijuana slows down the nervous system of dogs and cats, alters the heartbeat, and induces vomiting (17).
The nicotine in tobacco disrupts the proper functioning of the digestive and nervous systems (18). An elevated heart rate, coma, and death can result from nicotine poisoning in cats and dogs (18).
13. Christin Allen (October 2001). "Treacherous Treats – Macadamia Nuts". Veterinary Technician. http://www.aspcapro.org/mydocuments/zj-vettech_1001.pdf. Retrieved October 20, 2012.