Human food poisonous for dogs

Most people know chocolate isn't good for dogs, but do you know why? Do you know the less common poisons? Do you know why a certain food is dangerous for dogs?


This list is intended to both give you a quick overview of substances that are potentially harmful to dogs. It will also help you navigate and find the exact description of symptoms and causes of the specific foods/substances dangers.

Too much alcohol isn't good. It's not good for humans and neither is it good for dogs. Especially young dogs/puppies should not get in touch with alcholic beverages or other alcoholic substances.
By the way: if a dog eats yeast dough this can lead to alcohol poisoning as the yeast converts sugar to alcohol.

The thing about Chocolate
Symptoms of chocolate poisoning are:
  1. vomiting
  2. diarrhoea
  3. extensive drinking
  4. extensive urination
  5. hyperactivity
The reason why chocolate is a health risk is that it contains theobromine which can lead to irregular and/or slowed heart beat and eventually heart failure in dogs.
Symptoms may not always appear right after chocolate ingestion. There are discrepancies about the amount of chocolate to cause problems, in part because it depends on the individual dog, their immune system, their physical condition, age, weight, etc. Death due to theobromine poisoning will usually - but not always - occur within 24 hours.
A dog who has eaten a lot of chocolate should not be exercised vigorously and be kept as quiet as possible as exercise increases the chance of heart failure due to the extra strain on the heart.
By the way: the theobromine is only in the cacao, so white chocolate or cacao butter isn't harmful.

Symptoms of onion poisoning are:
  1. vomiting
  2. diarrhoea
  3. red/bloody urine
  4. breathlessness
Onions contain thiosulphate which leads to haemolytic anaemia. This fancy term means that the red blood cells are destroyed. If there are not enough red blood cells the animal can die because the main task of red blood cells is oxygen transport and lack of red blood cells means lack of oxygen in the organs which will lead to organ failure and thereby death. Symptoms can occur days after the dog has been eating onions!
If onion poisoning is detected on time and the dog is given a blood transfusion for the time it takes for the onion to pass through the dogs system a full recovery is very likely.
The risk does not only exist for raw onions but also for cooked or dried onions!

Unbeknownst to many people the risks of garlic are similar to those of onion. However, garlic also has great health benefits. Dog owners should be aware of this and make their own decision about if and how much garlic they want to feed their dogs.

Macademia nuts
Symptoms of macademia nut poisoning are:
  1. tremors in the hindlegs
  2. paralysis
  3. obvious pain
  4. trouble getting up (coordination problems)
  5. painful movments in general
It is not known what exactly causes the adverse effect of macademia nuts. However, dogs will not die of them but slowly recover. However, it is painful and unpleasant for the dog to have these locomotary problems.

Symptoms of avocado poisoning are:
  1. difficulty breathing
  2. abdominal enlargment/bloating
  3. fluid accumulation in the chest, abdomen or the tissue sourrounding the heart
The avocado fruit as well as its pit and the rest of the avocado contain persin which is poisonous to dogs and most other domestic animals. It will permanently damage a dogs heart, lung and other tissues. An added problem is that dogs not used to eating fat (and avocado has a very high fat content!) can develop pancreatitis - an inflammation of the pancreas.
Due to the persin it is potentially leathal to dogs due to heart, lung or other organ failure. It is so far not entirely clear why persin has this effect on dogs and other domestic animals but is generally harmless to humans.

Symptoms of tomatine poisoning are:
  1. lethargy
  2. drooling
  3. difficulty breathing
  4. colic
  5. vomiting
  6. diarrhoea
  7. constipation
  8. dilated pupils
  9. paralysis
  10. heart problems
  11. ataxia (loss of muscle coordination)
  12. muscle weakness
  13. tremors
  14. seizure
  15. potentially coma
  16. potentially death
The tomatoe plant as well as the tomatoe fruit contain tomatine which is a alkaloid (bitter taste) and hence acts like a poison. The tomatine content will lessen with riping and a very ripe, red tomatoe will contain only little tomatine. The jury is still out on whether or not it is a good idea to give reasonably ripe tomatoes to dogs.
Tomatoes also contain atropine which is poisonous to humans and dogs alike. The atropine content is highest in stems and leaves, it is very low in ripe fruit.

Nutmeg is unhealthy to humans and dogs alike. It is a "psychoactive" substance and can lead to tremors, seizures and death.

Caffeine is dangerous to dogs the same as it is dangerous to humans. Too much is not a good idea. Excess caffeine will lead to:
  1. difficulty breathing
  2. vomiting
  3. diarrhoea
  4. abdominal pain
  5. tremors
  6. increased heart rate
  7. potentially death
Keep in mind that ground coffee beans, whole coffee beans and tea leaves do contain quite a bit of caffeine! Hence: Not a good snack for dogs!

Raisins and Grapes
Raisins and Grapes are known to cause kidney failure and death in dogs. It is unknown why this is the case but the danger is often underestimated. It is also unknown what a "leathal dosis" of raisins or grapes would be. Unfortunately cases of medium sized dogs are known that died after just a couple of raisins (less than ten) while other dogs eat huge amounts of raisins or grapes without showing outward symptoms. It is however a fact that raisins and grapes CAN and WILL kill dogs. This can be due to small amounts over a longer period of time or through one huge "meal" of raisins and/or grapes.

Fruit pits and stones
While fruit is healthy for dogs and there is no problem with feeding skins and even stems (not sure WHY one would do that, but so what) it is not a good idea to have dogs eat large amounts of pits, stones and seeds. These often contain cyanide which is poisonous to dogs as well as humans. However, truth be told you would have to feed a dog A LOT of these in order to cause harm.

Xylitol is an artifical sweetener commonly used in human food. Especially "sugar free" sweets and chewing gum contain xylitol but it can be found in a wide variety of foods. Xylitol is known to cause a rapid decrease of the blood sugar content and thereby potentially cause death.
Xylitol can also cause seizures in dogs!

Raw Green Beans/raw red and white kidney beans
Raw Green Beans/raw kidney beans (white and red) are in fact poisonous to both humans and dogs. This is because they contain phytohaemagglutinin which leads to an amino acid imbalance which leads to the general signs of poisoning (vomiting, weakness, diarrhoea, etc). The amino acid imbalance leads to problems in bone formation and bone and joint problems (and pains) in general. Usually the poisoning will pass by in aboput five hours without medical assistance (except in extreme cases!) Phytohaemagglutinin is destroyed by cooking.

Potatoes with green spots
The green spots in potatoes are not necessarily problematic, however, when exposed to light (and that is the reason potatoes get green to begin with) the likeliness of the formation of soline is significantly increased. Soline is a glycoalkaloid toxin. Once the green parts ar removed, however, they are safe to eat. This should be removed before boiling as otherwise a bitter taste can occur. Signs such as vomitin and diarrhoea can indicate a soline poisoning.

Unfortunately persimmons are potentially harmful for dogs. For reasons not entirely clear they cause infectious enteritis - an inflammation of the small intestines that can lead to serious health problems if undetected and/or untreated.
Diarrhoea and signs of stomache pain are likely to occur

Hops (the stuff used in brewing beer)
Hops is very healthy for humans. However, in dogs it is very harmful and potentially life-threatening.
Symptoms from hops poisoning are
  1. excessive panting
  2. elevated temperature
  3. potentially seizures
  4. potentially death

Raw pork
Unfortunately the Aujetzki-Virus is a substantial risk in terms of raw pork as it causes pseudorabies. There are countries where it is believed to be extinct but it is certainly a good idea to make sure in advance if it is a danger in the part of the world one lives. In the end - better safe than sorry! - it's maybe best to cook pork if in doubt. Symptoms can be:
  1. coughing
  2. sneezing
  3. fever
  4. constipation
  5. depression
  6. seizures
  7. ataxia (loss of coordination of the extremities)
  8. excessive salivation
  9. itching
  10. jaw and pharyngeal paralysis
Death will occur within days, within a months at the very latest. There are NO cures for pseudorabies.


I have to admit that this information has been collected from a wide area of sources. Mostly the information comes from various books - both in German and English - concerend with dog rearing, dog nutrition and just "general dog books". Some information came from leaflets I have collected in various veterinarians waiting rooms in both Finland and Germany. I won't deny some information may come from the internet but I did not reproduce that without verifying it through different written sources because I have some suspicion in terms of trusting heresay which I believe a good bit of the internet to be about. So I may use information I aquire that way and then try to verify it.

NB: this is not an exclusive list; the author does not guarantee the accuracy of this information or accept responsibility for harm caused through it

This article may be reproduced freely with proper reference to the author.

  Visitors since 12 September 2008