Are tomato plants poisonous?

In this article, we will answer the question “Are tomato plants poisonous”? and discuss the cooking effect on tomato leaves and the effect of tomato leaves on cats and dogs. 

Are tomato plants poisonous?

No, tomato plants are not poisonous. Tomatoes won’t kill you until you consume a lot of potato plants. Tomato stem, leaves and roots contain an alkaloid known as tomatine which is slightly toxic to humans and can cause some gastrointestinal issues.

Tomato leaves have an unpleasant smell that discourages people from eating them. You can eat them, you can use one or two leaves to add tomato flavour to the recipe.

Can cooking reduce alkaloid levels in tomato leaves?

Cooking can’t destroy the alkaloid level in tomato leaves because they are very stable and can’t break even at very high temperatures. But when you boil leaves in the water alkaloid dissolves in the water. If you want to use potato leaves, boil them in water and drain the water to avoid the toxicity of alkaloids.

Green tomato fruit               

Green fruit also contains alkaloids and you should avoid green potatoes. If it is necessary to use green potatoes in the recipe like tomato chutney, fried green tomato and tomato relish you should use tomatoes that are near to ripe as they have less alkaloid as compared to early green tomatoes.

Alkaloid levels decrease when the tomatoes are ripe or near to ripe, so use them in a recipe to minimize the risk of toxicity. If cooked green tomatoes have a bitter taste it means that they have a lot of alkaloids so avoid eating them.

Tomato toxin alkaloids may be toxic to insects. Tomatine alkaloids have fungicidal properties so some former use potato leaves as insecticides for insects, especially for aphids. They soak tomato leaves in water then spray this water against insects.

Are tomato leaves toxic for dogs?

Tomato leaves are toxic for dogs if they eat a bunch of leaves. The consequences depend on the dose of tomatoes. Dogs can eat all crazy things and you don’t know how to stop. 

Dogs can eat a lot of tomato leaves if they are not trained to stay away from leaves and have access to the garden. If the small dogs ingest the leaves it can cause diarrhoea and vomiting, visit the hospital if they have a severe problem.

The toxicity of dogs is not equal to the toxicity of humans. Some food is poisonous to dogs like grapes, onion, raisins, chocolate and garlic but these are harmless to human beings.

Are tomato plants poisonous for cats?

Tomato plants are poisonous to cats. Tomato plants contain solanine that is toxic to cats. If cats eat tomato plants, they can cause illness in cats.  

Symptoms of tomato plant poisoning

Symptoms of tomato plant poisoning in cats include:

  • Excessive salivation
  • Lack of appetite
  • Diarrhoea
  • Severe stomach upset
  • Vomiting
  • Confusion
  • Drowsiness
  • Apathy
  • Behavioural changes
  • Physical weakness
  • Slow heart rate
  • Central nervous system depression
  • Dilated pupils

When cats ingest green parts of tomato plant like leaves, stem and unripe fruit, cats show the above symptoms because the green parts of tomato contain solanine and alpha tomatine. The risk of eating tomato plants increases when they are getting bore and have access to tomato plants they can eat a lot of plants.

If your cats eat too much tomato you should consult a vet for treatment. If they have pain then your vet will examine the irritation in the lips and mouth. For a complete blood count and chemistry panel, your vet will take the blood from your pet. 

Your vet will also take the urine sample to check the proper function of the kidney. If there are severe symptoms then your vet will run an ECG to check the heart function.

How to treat tomato plant poisoning in cats?

Tomato plant poisoning treatment depends on the number of plants that cats ingest. Your vet induced vomiting by using 3% hydrogen peroxides if the cat ate too much tomato leaves. After that, he will neutralize the remaining toxin by using activated charcoal.

When they become dehydrated, your vet can offer electrolyte and intravenous solutions to replace the fluid in cats. If they have difficulty breathing, provide supplemental oxygen. The vet may have provided the vasopressor if the cat has cardiovascular symptoms. Large amounts of tomato plants can cause convulsion than you can use diazepam.

If the cats eat a small part of tomato plants they may recover soon without any treatments. But if your cat eats a lot of tomato plants you should contact a vet for possible treatment. Your cat will be fully recovered when all the toxins are removed.

To avoid toxicity in the cats you should keep the cats away from the tomato plants. You should retrain the cats inside and buy cat-friendly plants for her and place them in different areas of your house for your cat to nibble on.

Other FAQs about Tomatoes that you may be interested in.

Can you eat a tomato with seeds sprouting inside?

Are Plum and Roma tomatoes the same?

7 ways to preserve tomatoes


In this article, we answered the question “Are tomato plants poisonous”? and discussed the cooking effect on tomato leaves and the effect of tomato leaves on cats and dogs. 

If you have any questions or comments please let us know. 


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