Can Dogs Eat Tomatoes?

Tomato is a wonderfully sweet, flavorful fruit. Tomatoes are antioxidant, anti-inflammatory and have anti-cancer properties. So they’re also good for you (1).

But … can dogs eat tomatoes? There isn’t really a straightforward yes or no answer to this question. Tomatoes have many health benefits for dogs … but also a couple of cautions.

Health Benefits Of Tomatoes For Dogs

Tomatoes are members of the nightshade family of vegetables. Other nightshades are potatoes, peppers and eggplant. More than 2,000 plants are included in the nightshade family (Solanaceae) ­and most aren’t eaten. But, for the handful that we enjoy as food, they’re long time staples in our diets. However, there are some potential drawbacks to nightshades, described later. 

Tomatoes have high nutrient density and low calorie content, making them popular for healthy eating. They are also rich in antioxidants, vitamins A and C, fiber, potassium, Vitamin B6 and manganese.

Antioxidants are beneficial to any diet. They help dogs to keep harmful free radicals in check and prevent oxidative stress. Research shows that tomatoes and products from tomatoes can lower the risk of cancers and cardiovascular disease, can help with hormones, immune systems, and metabolic pathways, and reduce the chances of inflammatory diseases like obesity, diabetes, and hypertension (2, 3).

Helpful Nutrients In Tomatoes

Here are some of the powerful nutrients in tomatoes.

Beta-Carotene
Beta-carotene helps with vision, the immune system, cancer prevention, sun protection and cognitive function. Beta-carotene is pro-vitamin A; meaning it converts to vitamin A in the body. Vitamin A is necessary for healthy coats, skin, muscles and nerves … from nose to tail.

Lycopene
Lycopene is the carotenoid responsible for the color of tomatoes. It helps protect against sunburn. The redder and riper the tomato, the more lycopene it contains. Research shows lycopene can reduce the risk of chronic diseases like cardiovascular disease and cancer (4) … especially prostate, lung and stomach cancers (5).

Vitamin C
Vitamin C reduces allergy symptoms, helps with forming calcium and iron, boosts the immune system, grows and repairs tissue and helps the adrenal gland to function properly. Unlike humans, dogs make their own vitamin C and don’t need to rely on their diet. But a boost of vitamin C from food can be good for dogs, especially those older than 7 years old, or those experiencing stress.

Fiber
Soluble and insoluble fiber are essential for your dog’s gut health. Fruits and vegetables are great sources of both types. The soluble fiber, which is prebiotic, feeds the bacteria living in the colon and helps your dog’s immune system. With nearly 90% of the immune system in the gut, soluble fiber is an important part of your dog’s ability to resist disease. 

In tomatoes, 87% of the fiber is insoluble. This type of fiber adds bulk to your dog’s stool, and helps regulate bowel movements. Additionally, insoluble fiber strengthens and renews the cells lining your dog’s gut, helping protect against problems like leaky gut.

How To Feed Your Dog Tomatoes

Always choose local and organic produce when you can. Raw tomatoes are the most nutritious way to feed them. 

Tomatoes should be allowed to ripen naturally, and, as you’ll read below, only feed completely red, ripe fruit to avoid any food intolerances. Never feed your dog green tomatoes or the leaves and stems.

It’s best to remove seeds and skin before feeding. That’s because lectins, which can be harmful for your dog’s gut, are in the skin and seeds – and their risks outweigh the benefits of any additional lycopene in the skin. To boost lycopene absorption, give your dog tomato with a healthy fat.

Potential Tomato Intolerance In Dogs

As mentioned earlier, tomatoes are members of the nightshade family (along with potatoes, eggplant and all types of peppers). Nightshades can cause food intolerances due to two alkaloids in nightshades: solanine and tomatine. 

Solanine is an alkaloid that can be toxic to dogs (and some people). It’s found in tomatoes and potatoes … especially when they’re green (6). Large amounts of solanine can be poisonous. But your dog would have to eat a lot of green tomatoes to get sick.  

Tomatine is another alkaloid that can be mildly toxic. Tomatine is in tomato stems and leaves, as well as green, unripe tomatoes (7). 

So if you do give your dog tomatoes, make sure he only eats ripe, red tomatoes and never give him green tomatoes, or the tomato plant’s stems or leaves. And if you have tomato plants growing in your garden, be aware of the signs of toxicity, in case he helps himself to a snack. 

Signs Of Tomato Poisoning In Dogs

• Signs of solanine poisoning include vomiting, diarrhea, lethargy, weakness and confusion. 
• Signs of tomatine poisoning are digestive upset, ataxia or loss of coordination, weakness, tremors or even seizures. 

if you notice any of these symptoms, contact your vet immediately. 

Dogs Who Shouldn’t Eat Tomatoes

Tomatoes aren’t healthy for all dogs. Avoid tomatoes for dogs with acid reflux, dogs with food sensitivities or allergies, or dogs with arthritis (it’s widely thought solanine can aggravate arthritis, though studies haven’t confirmed this.)

Safe Alternatives To Tomatoes For Dogs

For most dogs, fresh ripe tomatoes are an excellent source of antioxidants and vitamins that may help with disease prevention. As with any fruit or vegetable, buy local local and organic if you can. Give tomatoes in moderation and  keep an eye on your dog for any signs of intolerance or stomach upset. 

References

1. Salehi B, Sharifi-Rad R, Sharopov F, et al. Beneficial effects and potential risks of tomato consumption for human health: An overview. Nutrition. 2019;62:201-208. 

2. Blum, A, Monir M, Wirsansky I, Ben-Arzi S. The beneficial effects of tomatoes. Eur J Intern Med. 2005;16(6):402-404. 

3. Raiola A, Rigano MM et al. Enhancing the health-promoting effects of tomato fruit for biofortified food. Mediators Inflamm. 2014;2014:139873. 

4. Rao AV, Agarwal S. Role of antioxidant lycopene in cancer and heart disease. J Am Coll Nutr. 2000 Oct;19(5):563-9.

5. Giovannucci E. Tomatoes, tomato-based products, lycopene, and cancer: review of the epidemiologic literature. J Natl Cancer Inst. 1999 Feb 17;91(4):317-31.

6. Donald Barceloux, MD. Potatoes, Tomatoes and Solanine Toxicity (Solanum tuberosum L. Solanum lycopersicum L). Disease-a-Month 55.6 (2009): 391-402. 

7. Yaohua You et al. Bitter and sweet make tomato hard to (b)eat. New Phytologist, Volume 231, issue 1, April 2021.