Poisonous Frog

How to tell if a Frog is Poisonous

Author: John Wellington

Updated: May 4, 2018

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There are over 4,700 species of frogs inhabiting every continent except Antarctica. Out of those, there are more than 100 species of poison-dart frogs. These brightly colored frogs inhabit the rainforests of Central and South America, Africa and other tropical and subtropical regions. They look beautiful but they carry with them a deadly alkaloid toxin. The side effects range from mild irritation to paralysis and even death. Aside from frogs, there are nearly 200 ‘true toad’ species, of which a handful of them harbor bufotoxins, which are harmful to humans and deadly for animals.

There is a difference between a frog and “true toad” but that’s a topic for another post. Because people often use ‘frog’ and ‘toad’ interchangeably, I’ve decided to include them in this article. Yes, some toads are poisonous. They secret toxins from what are called parotoid glands, which are located just behind their eyes. So, without further a due, I’ll show you some characteristics of poisonous frogs and toads. To finish things off, I’ll tell you about another potentially deadly thing frogs are carrying.

Brightly Colored Frogs Might Be Poisonous

The most defining feature of a poisonous frog is its color. A bright, colorful frog may or may not be poisonous. As such, I strongly recommend treating all brightly colored frogs as poisonous, especially frogs from Central and South America and Africa. Don’t touch them! They look pretty, yes, but snatching up one of the more dangerous species can result in severe injury and even death.

Examples of Poisonous Frogs

This is an illustration of six poisonous frogs. There are around 100 species of poison-dart frogs, all of which have varying colors and patterns. Photo credit: Doloves / Fotolia

The reason the heading for this section reads “brightly colored frogs might be poisonous”, ‘might’ being the key word, is because not all colorful frogs are poisonous. Some species mimic poisonous frogs in appearance, all-the-while not containing very potent toxins at all.

In the animal world, bright colors mean “stop!” “I’m dangerous”. This system tends to work, as bright colors often suffice in deterring would-be predators whether or not the animal is poisonous or not. This is why I included ‘might’, but again, unless you’re traveling with a trusted professional, treat every bright, colorful frog as poisonous; do your best to avoid them.

An interesting fact about poison-dart frogs is, they only produce poison by eating alkaloid-container insects. At least that what researchers suggest. In fact, people have been keeping poison-dart frogs as pets for years, and it’s completely safe. In captivity, they’re usually fed small crickets or fruit flies which don’t contain alkaloid.

A frog might be poisonous if:

  • Has bright, colorful skin
  • Inhabits South America, Africa, or other tropical regions
Poison Dart Frog

Phyllobates bicolor is the 2nd most deadly frog in the world. It is similar in appearance to that of the Golden Poison Frog.

The deadliest frog on earth belongs to the Phyllobates Genus. Its scientific name is Phylobbates teribilis which roughly translates to “dreadful leaf-climber”. Its common-name is Golden poison frog and it has the deadliest poison of all. An average adult contains enough poison to kill two full-grown African bull elephants.

Some Toads Are Poisonous

There are some differences between frogs and toads but I won’t dive into that subject here. The reason I’m mentioning toads is that a lot of people use ‘frog’ and ‘toad’ interchangeably. Due to this, I added toads to this article because they can be harmful to humans and fatal to animals.

Cane Toad Bufotoxin

Toxin secreted from a parotoid gland of a cane toad. Photo credit: ourherpclass.blogspot.com

Toads carry bufotoxin in their parotoid glands, which are located behind their eyes. If the toxin were to come in contact with your mouth or eyes, it can be harmful; resulting in an allergic reaction, vomiting, and general discomfort. But, in most cases, this won’t happen because toads cannot excrete the substance on purpose. It has to be squeezed out. This is why animals are more at risk than humans. A playful cat or dog might fall victim to a toad if they bite and squeeze out the toxin. Cane toads are an invasive species in Florida and one to watch out for. American toads are another; they inhabit Central and Eastern United States.

Suffice to say, you probably don’t have to worry about toads. If you happen to pick one up, just be mindful not to squeeze their parotoid glands. Should you happen to squeeze some bufotoxin out, gently sit the toad down and go clean yourself. Don’t rub your eyes or touch your mouth.

It’s not just poison you have to worry about

In general, it’s best not to handle frogs. Chances are, you’re going to cause unwanted stress for them. Not only that, their skin is semi-permeable, so any chemicals on your hands will likely be absorbed by the frog, causing even more damage. I imagine if you’re reading this post, you’re generally concerned about poisonous frogs and you want to be safe. Whatever the case, it’s important to know that while not all frogs are poisonous, they have been known to carry salmonella.

Salmonella is not a poison, it’s a bacteria. It can be spread through amphibian droppings. To keep yourself safe, always wash your hands and use sanitizer if you happen to touch a frog or its droppings. And be mindful of children, as they like to pick up frogs and toads! I hope this post was helpful to you. If you enjoyed it, please consider sharing with family and friends.

31 Questions & Answers

  • Peggy

    Hey John, Pottsville, PA here found a tiny rust colored frog and it looks like it has armor plating. This little guy was not round but shaped like it actually had plating. More geometrical or rectilinear. Not scales. Could you please tell me what type of frog this is? Is it poisonous? Could it possibly be poisonous to dogs? I should have taken a picture of it, but didn’t have my cp at the time. Your feedback and answers will greatly appreciated.

    • John Wellington

      Hi Peggy! I’m sorry, I can’t think of a frog that looks like what you described in PA. Spring peepers can have a rust color but they have smooth skin.

  • Kylah Nash

    I caught a toad a little while back and brought it home and he seems to be doing really well but I’ve tried to give him other bugs to eat like flies and other things but he only eats crickets and one time he ate a butterfly but I’m just wondering what are some other things i should try to feed him

      • Kathleen Jaramillo

        Hey John,
        Just wanted to thank you for the interesting read and your thoughtful answers! I randomly found your page because my puggle found a bull frog (I think – round, brownish/grayish/greenish cute fella) in our yard and was was barking away at it. We brought our dog inside and my husband put gloves on and helped the frog to safety. We live in AZ next to a golf course – what kind of frog/toad do you think it was?
        Thanks

      • John Wellington

        Hey no problem, Kathleen! Thanks for the nice comment! It’s hard to tell. It may have been a bullfrog or possibly a toad. How big was it? Here is a page with a list of possible frogs living in Arizona. I hope this helps!

  • Ham

    A small dart frog, as if green hopped onto my hand. I whisked it off immediately. But it left a liquid on my skin … Is this frog safe!?

    • John

      You should certainly wash your hands and see a doctor if you’re feeling weird. Where in the world do you live? Are you sure it was a dart frog?

      • Amanda

        Hi,

        I live in Florida and my room has a balcony that I like to open sometimes. It’s been raining a lot and I usually hear a frig on the sill but it’s at night mostly and I don’t think much of it. Tonight as I lay in bed the frog hoped on my pillow and now I’m scared I may be infected or have been infected by the frog as it managed to get into my room. What do I do.

      • John

        Wash your covers/pillow and maybe consider getting a window screen? You most likely had a tree frog jump on your bed. They’re fairly harmless and probably the only type of frog that could reach your balcony! If you’re feeling weird, give your doctor’s office a call and see what they say.

      • Iyanna

        If a from was light green and yellow spots is it poisonous????

      • John Wellington

        It’s hard to tell what type of frog you’re talking about based on that description alone. What part of the world did you find him in?

  • Alexis

    Hey, I’m from northern Kentucky and there was a frog I believe on my porch last night that I handled and then put in the grass. I wasn’t able to identify the frog or identify what kind of frog it may have been, but I’ve been super on edge about it and worried about it being poisonous and me not realizing it.

    • John

      Don’t worry too much. The chances of a poisonous frog being in Kentucky are slim-to-none. The only thing you need to worry about is salmonella. Wash your hands afterwards and you’ll be fine!

  • Shelly Bolles

    I have 2 dogs one is a German Shepherd the other is my baby she is a rat terrier who sees a frog and won’t stop til she gets it or I catch it and release it back outside thank God my dogs have not come in contact with them we have American tree frogs everywhere here in southern Florida and huge toads that I know is dangerous for my fur babies

  • Cecelia Kane

    Great article! What are some examples of brightly colored frogs which are not poisonous? I am writing a paper about dishonest signaling and this would be an interesting example.

    • John

      All frogs are mildly toxic to some degree. The Allobates zaparo is one that mimics more toxic species meanwhile it is not very harmful itself. Check out this article for more information.

  • Amit

    Hi and thank you for the interesting article.
    I am interested in knowing about brightly colored frogs that are not poisonous, can you please name one?

    • John

      They’re all mildly toxic to some degree. Allobates zaparo is a species which isn’t nearly as harmful as the Phyllobates Terribilis for example. Aside from poison-dart frogs you’ve got species like the Red-Eyed Tree Frog which has bright blue, orange, red, and green colors. RETF toxins are mostly harmless to humans but they might be irritating to a small animal.

    • John

      The size isn’t necessarily a problem. If the frog was wild, you shouldn’t keep it. Opt for a captive-bred frog instead!

  • Lisa Condon

    Hi. Years ago I spent time in the remote part of the State of Sao Paulo, Brazil. I came upon a huge frog or toad living in, near a pond. It was at least 1 foot in length, green and beige.
    The Brazilians warned against anyone touching it. Do you know what it might have been.

    • John

      My only guess is a bullfrog or a large “True Toad” (Bufonidae family), although they wouldn’t be that big. Bullfrogs can get pretty big but they’re not exactly dangerous either. There are poison-dart frogs in brazil but they’re not that big. I’m sorry, Lisa, I’m at a loss for what kind of frog/toad they were talking about. Goliath frogs grow up to 12″ in length but they’re native to Africa.

  • Dennise Lopez

    Hello, I’m from Texas and there is always a small green frog hanging around at our door and I was wondering if you can let me know if it could be poisonous please. I have an app that identifies plants and animals with pictures and it had said the frog was a Holarctic Tree Frog but I am not sure if it is poisonous and if I should stay away from it.

    • John

      Hello, Dennise. The frog hanging out around your door is (probably) an American Green Tree Frog. They’re native to Texas (mostly the eastern parts of Texas) and they’re small, green frogs.

      Most frogs have a mild amount of toxin but its rarely noticeable to humans. The chances of you running into a dangerous, poison-dart frog in Texas are slim-to-none. It’s too hot and dry for them.

      Anyway, American Green Tree frogs are harmless 🙂 I don’t recommend grabbing one unless you need it. Touching one will hurt the frog more than you. But, if you have to, make sure to wash your hands afterwards. Frogs can transmit salmonella through their droppings – read the last two paragraphs of this page for more information.

      • Anonymous

        i saw a frog outside of my door ond my mom held it. it was small and green.

  • Mona Dominguez

    I was unable to say for sure if the sierrian tree frog is harmful to my small dogs if ingested as my yard is teeming with them.

  • Kerin Stevens

    I want to know what frogs and Tods in Florida are bad for you ….and I want to know what they look like and if you add the good frog to thx this was helpful

    • John

      No problem, Kerin – I’m glad this was helpful! I’m not very familiar with the different types of frogs in Florida but I feel confident in saying that cane toads are probably your biggest worry. They’re an invasive species, mostly a threat to pets and animals (especially dogs). Click here for info about frogs in Florida. Some parts of Florida might have the correct environment to support poison-dart frogs but I haven’t read any reports of this happening.

  • Anthony

    Hi I’m from Indiana and a frog living in soil sprayed pee into my eye and I flushed it with water and wondered if you had any suggestion to weather I should be at any panic . I’m from Indiana in the USA .

    • John

      Hey, Anthony. I’m sorry to hear that happened to you. Amphibians can carry salmonella and it’s often transmitted through their droppings. Don’t panic, though; not all amphibians have salmonella. I’m not qualified to give medical advice but I’d recommend calling your doctor to see what they recommend.

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