Tomato leaf and stem
ToxicASPCA classifies the tomato plant (Lycopersicon spp.) as toxic to dogs, with solanine as the toxic principle and dilated pupils and a slow heart rate among the signs. The leaves and stems are never a food.
This food guide has not been reviewed by a veterinarian. It summarises general information from sources and should not be used to decide whether a food is suitable for an individual dog or to assess an emergency.
Check before feeding
Do not offer as a treat
There is no recommended treat portion for this hazardous item. If swallowed, contact a vet with the amount, time and product details. Do not induce vomiting yourself.
Signs and health concerns
This list includes both observable signs and conditions identified through examination or testing. It cannot establish the cause or whether an exposure is safe.
- Excessive salivation
- Loss of appetite
- Vomiting
- Diarrhoea
- Reduced activity and responsiveness
- Weakness
- Poor coordination or balance
- Dilated pupils
- Slow heartbeat
- Irregular heartbeat
- Tremors
More about this food
The tomato plant and the tomato fruit are two different safety questions. The ASPCA toxic plant database lists the tomato plant, Lycopersicon spp., family Solanaceae, as toxic to dogs. It gives solanine as the toxic principle and the clinical signs as hypersalivation, inappetence, severe gastrointestinal upset, depression, weakness, dilated pupils and slow heart rate, then closes the entry with the line that matters most: ripe fruit is non-toxic. The danger is the leaves, stems, vines, flowers and unripe green fruit.
The compounds are glycoalkaloids, tomatine and solanine. They damage cell membranes, irritate mucous membranes, and act on the gastrointestinal tract, the nervous system and cardiac conduction. Levels drop sharply as fruit ripens, but they stay put in the green tissue, which is why one plant produces two completely different answers depending on which part your dog chewed.
Exposure almost never happens in the kitchen. It happens on a patio or in a garden bed: a potted cherry tomato on a deck, a pile of suckers pruned off and left on the ground, leaves knocked loose while tying up a cage, green fruit dropped between rows. Tomato foliage has that distinctive sharp green smell, and some dogs, puppies especially, will mouth a plant because of it.
One honest caveat. Pet Poison Helpline notes that severe poisoning is relatively uncommon and that a dog would typically need to eat a significant amount of the plant to show serious effects, though smaller dogs can show milder signs on less. That is a reason not to panic over one chewed leaf. It is not a reason to treat foliage as food.
Signs usually begin within a few hours: drooling, refusing food, vomiting, diarrhea, lethargy, muscle weakness, loss of coordination, dilated pupils, a slowed or irregular heart rate, and tremors. If your dog has been eating tomato foliage, call your veterinarian or the ASPCA Animal Poison Control Center at (888) 426-4435 now, and do not wait if you see wobbliness, tremors or heart rate changes. Do not induce vomiting at home; decontamination and activated charcoal are veterinary decisions. Prevention is simple: raise the pots out of reach and clear pruned vines away as you cut them.
Frequently asked questions
- My dog chewed one tomato leaf off a patio plant. Is that an emergency?
- A single leaf rarely causes severe poisoning, but the foliage is not a safe part of the plant. Watch for a few hours for drooling, vomiting, diarrhea, lethargy or wobbliness, and call your vet if any appear or if your dog is small.
- He got into a pile of pruned tomato vines. What should I do?
- Call your veterinarian or the APCC at (888) 426-4435 now. Stems and leaves carry the highest glycoalkaloid load, and a large amount can bring dilated pupils, a slow heart rate and tremors on top of the GI signs. Do not induce vomiting at home.
- Are cooked tomato leaves or stems any safer?
- No. Cooking does not reliably break down glycoalkaloids, and foliage is not food for people either. Limit tomato to fully ripe red fruit, in moderation, and compost the rest of the plant out of reach.