10 Common Foods that are Harmful to Pets

Posted by Karen Egert on

We all love our pets and want to give them the best things we can.  We know we should help them watch their diets.  Sometimes it can be very hard to resist those big brown eyes begging for some of the food we have but here are some foods you should definitely avoid giving your pet.


Avocados contain persin which is a fungicidal toxin.  The amount considered to be toxic is unknown at this time.  Symptoms include gastrointestinal irritation, vomiting, diarrhea, difficulty breathing, abdominal enlargement and abnormal fluid accumulations in the chest, abdomen and sac around the heart.  In addition, some dogs will eat the pit or parts of it and this can cause intestinal blockage.  Avocado pits have had to be surgically removed from dogs.


Chocolate contains theobromine, a compound that is a heart stimulant, diuretic and is used in medicine as a vasodilator.   Symptoms include excitability, hyperactivity, muscle twitches, excessive panting, vomiting and diarrhea.  Because of the diuretic effect, your dog may pass large volumes of urine and be unusually thirsty.  Theobromine can increase the dog’s heart rate, increase blood pressure, and cause the heart to beat irregularly.  In severe cases, seizures can occur.  

How much chocolate will hurt my dog?  That depends on the type of chocolate and the amount of theobromine it contains. 

  • White chocolate has 1mg theobromine per ounce.
  • Milk chocolate has 60 mg per ounce.
  • Semi-sweet chocolate has 260mg per ounce.
  • Baking chocolate or unsweetened chocolate has a whopping 450mg per ounce
  • Dry cocoa powder has 800mg per ounce.

Below is a quick reference of harmful levels:

Dog’s weight

Amount of milk chocolate

Amount of baking chocolate

Appr. Mg of theobromin

5 lb. 4 oz. 0.5 oz. 200
10 lbs. 8 oz. 1.0 oz. 400
20 lbs. 1 lb. 2.5 oz. 900
30 lbs. 2 lbs. 3.25 oz. 1300
40 lbs. 2.5 lbs. 4.5 oz. 1800
50 lbs. 3 lbs. 5.5 oz. 2250
60 lbs. 4 lbs. 7.0 oz. 2700
70 lbs. 5 lbs. 8.5 oz. 3400


Onions and garlic contain the toxin S-methylcysteine sulfoxide.   In pets, these foods can cause Heinz body anemia.  This is a condition where the red blood cells are destroyed.  The affected cells develop an abnormality called a “Heinz body” which can be seen under a microscope.  A Heinz body is a small bubble-like projection which protrudes from a red blood cell.  The bubble is a weak spot and causes the cell to have a decreased life span and rupture prematurely.   Symptoms can include vomiting, diarrhea, anemia, weakness, liver damage, asthma attacks, discolored urine and contact dermatitis.  Please note that is does take fairly large amounts to produce harmful effects.  Cats seem to be more sensitive than dogs.  The small amounts found in commercial pet foods have not been shown to cause problems.

Macadamia Nuts

 Both raw and roasted macadamia nuts can cause temporary paralysis in a dog’s hind leg.   It is not known what toxic compound is in the nuts at this time.  Your dog may develop muscle tremors and weakness in their back legs.  They may be unable to rise and show signs of distress such as panting.  Their limbs may also swell and show pain when the limb is manipulated.  Only one ounce of nuts can cause this condition in a 20 pound dog.  Fortunately most recover in a few days.

Apple Pips

Apples?!?  Really???  While the fleshy parts of apples are just fine for your dog the seeds are not.  The kernels of plums, peaches, pears, apricots and apple core pips (seeds) all contain cyanogenic glycosides which can result in cyanide poisoning.   Symptoms include vomiting, listlessness, and excessive drooling.


Coffee grounds and beans have caffeine which is potentially toxic to dogs.  Caffeine will over stimulate the central nervous system and the symptoms are similar to chocolate toxicity.    

Grapes & Raisins

Grapes and raisins are both toxic to dogs especially when eaten in large quantities and can result in kidney failure.  Symptoms include vomiting and diarrhea.  Severe kidney symptoms will begin about 24 hours after the grapes/raisins have been consumed.   The amount of grapes resulting in poisoning varies but according to vets it is between 0.41 and 1.1 oz per kilogram of body weight.  Because of the possibility of death, vets at the ASPCA poison control center recommend aggressive treatment including inducing vomiting, stomach pumping and administering activated charcoal and IV fluid therapy for at least 48 hours.   

Yeast Dough

Raw bread dough made with yeast only needs a warm, moist environment to rise or expand.  If your dog eats dough, that dough can expand to many times its original size and cause gas accumulation in the digestive system.  This will distend the abdomen which is painful.  Another issue is the rising is caused by the yeast fermenting.  Fermentation results in alcohol which is also toxic.  Baking eliminates the danger and you can give your dog small pieces of bread as a treat.


You know that abuse of alcohol causes damage to the liver in humans but have you ever thought about what it can do to your pet?   Alcohol can be fatal for your dog because it contains ethanol.  All poisoning boils down to the amount of alcohol consumed compared to body weight so any alcohol can cause significant problems.  You will begin to notice symptoms within 15 to 30 minutes the alcohol was consumed on an empty stomach or 1 to 2 hours on a full stomach.  These symptoms include a slow respiratory rate, staggering, behavioral changes, increased urination, excitability, depression, seizures and even cardiac arrest.  Puppies and kittens are at particular risk because they are so small and their organs have not matured.

Excessive Fatty Foods (including Turkey skin) –

The pancreas is an important organ that produces enzymes. These enzymes break down foods into molecules the body can digest. These enzymes are handled by the pancreas in order to prevent them from damaging the pancreas itself or surrounding tissue. When these self-protective mechanisms break down for any reason, the result is leakage of enzymes which damages the pancreas and any surrounding tissue they reach. This breakdown is called pancreatitis.

Excessive amounts of fatty foods can cause pancreatitis.  Symptoms include abdominal pain, vomiting and diarrhea.  Your dog may show that it is pain through a hunched posture when picked up.  Miniature and toy poodles, cocker spaniels and miniature schnauzers are especially prone to pancreatitis.

Pancreatitis can be acute and only occur once in a dog's lifetime or it can become chronic and keep returning over and over again.  It can rapidly kill a dog or just be a mild attack of pain that goes away in a few hours or a day or so. It can also cause numerous side effects, including shock, blood clotting disorders, heart arrhythmias, liver or kidney damage and death.


What to do if you think your dog has been poisoned.

If you think your pet may have eaten a toxic food or other potentially deadly substance, you are urged to contact a veterinarian and/or an animal poison control hotline, such as the ASPCA Poison Control Center, which can be contacted by calling 888-426-4435.  The last time I checked there was a $65 consultation fee for this service.

Some specific things you can do to help your vet or the Poison Control Center are:

  • Don’t panic. Yes, it is important to respond quickly but you will be far more effective if you remain calm.
  • Take a few seconds to collect any of the material your dog may have eaten. If a trip to your vet is necessary, be sure to take the product container with you. You should also collect anything your pet may have chewed or vomited in a plastic bag.

Be ready with the following information:

  • The species, breed, age, sex, weight and number of animals involved.
  • The animal’s symptoms.
  • Information regarding the exposure, including the agent (if known), the amount of the agent involved and the time elapsed since the time of exposure.
  • Have the product container/packaging available for reference.

If your animal is having seizures, losing consciousness, is unconscious or is having difficulty breathing, take your pet to your vet or local emergency clinic.  You should call ahead to let them know to expect you.


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