My dog found this little frog/toad (I don't know the difference) and decided to carry him around in his mouth.

From what I read online some frogs/toads secret chemicals that are toxic (to dogs)...aside from transmitting warts (but maybe that's a myth).

Anyone know what this particular animal is, and any risks posed by this animal? (I'm located in Ontario Canada, in case that helps narrow it down)

The photos below looks a lot like this one so maybe it's a Woodhouse frog, which I think is harmless.

frog or toad

  • 4
    The transmission of warts is definitely a myth. Some toads and frogs secrete toxins. I don't know which species your one is, so can't make that call.
    – bob1
    Commented May 1 at 20:30
  • @TSG the picture isn't much like the other linked picture. Cropping the image to remove distracting detail gives better results on Google Lens. Commented May 1 at 21:57
  • @bob1 untrue, see Papillomaviridae, but the regular layout of the warts on this toad does suggest they may be a genetic property. Commented May 1 at 22:03
  • 10
    @WeatherVane The various Papillomaviridae are highly host specific to my knowledge (I'm a virologist, but don't work on the papilloma viruses), so there hasn't been any interspecies transmission definitively identified as yet, and certainly not between such highly divergent species as frogs/toads and humans as the myth goes. In addition, the "warts" on a frog/toad aren't caused by papilloma viruses...so there goes the myth!
    – bob1
    Commented May 1 at 23:06
  • @bob1 (with my apologies for doing this in comments, but you piqued my curiosity) I assume since these are viral, intra-species transmission of warts, from human to human say in the case of the various HPV-N viruses, does happen, right?
    – terdon
    Commented May 2 at 12:56

1 Answer 1


I think (and I am definitely no expert), that this is the American Toad (Anaxyrus americanus). It is unlikely to be a Fowler's Toad (Anaxyrus fowleri) or a Woodhouse's Toad (Anaxyrus woodhousii), or a hybrid between Woodhouse's and the American, as I will explain.

Frogs are generally considered to have smooth skin, which this doesn't have; it clearly has bumpy skin, so it is a toad. Note that this isn't a characteristic used by biologists, just an informal characterization used in general parlance.

According to Ontario Nature, the only two species of toad that are found in Ontario are the American Toad and the Fowler's Toad, so it shouldn't be a Woodhouse's Toad, as it isn't found in the province. If you use the map of distributions found here, you will see that the Fowler's toad is rare and only found in southern-most Ontario, near Lake Erie, while the American Toad is found throughout the province. Also on their page the description of the American toad, the distinguishing characteristic of the American toad from the Fowler's toad is the number of bumps/"warts" on the dark dots on its back.

From the Characteristics section:

The American toad is a large, squat toad with brown, reddish or olive skin and dark blotches containing one to two spots or “warts” of various colours. The belly is white with dark spots. These toads often have a light line down the middle of the back.

From the Similar Species section:

In extreme southern Ontario, the range of the American toad overlaps that of the Fowler’s toad. The best way to distinguish these two toads is by counting how many bumps are in each large dark blotch on the back. Fowler’s toads have three or four bumps per blotch, whereas American toads have one or two.

In your image you can clearly see one bump per dark spot on the back of the toad, as well as a lighter line down the back. The Ontario Nature photos (particularly the ones next to the Similar Species (reproduced below) and Threats and Trends sections ) clearly show a similar pattern of spots to the ones in your photo, whereas the ones for the Fowler's Toad show the smaller, higher number of bumps per spot.

American toad

Image copyright: Jason King, reproduced from Ontario Nature https://ontarionature.org/programs/community-science/reptile-amphibian-atlas/american-toad/

These toad species both produce a toxin from their skin, which does affect dogs (and presumably other species), but is apparently only enough to cause the dog to drop the toad; from the Ontario Nature site:

Both tadpoles and toads have poison glands in the skin that reduce their susceptibility to predators. A dog that picks up a toad will drop it and may foam at the mouth but will not be hurt.

  • 3
    Good answer Bob! This is indeed Anaxyrus americanus. It is neither a hybrid or a similar species.
    – Arrow
    Commented May 2 at 0:38
  • Thanks @Arrow Occam's razor helps a lot with these sorts of questions; it is almost never the uncommon species for statistical reasons, and a simple search for "toads of Ontario" led me to sites confirming it.
    – bob1
    Commented May 2 at 0:44
  • I find that really interesting. I didn't know Occamp's razor was a thing, haha!
    – Arrow
    Commented May 2 at 1:20
  • @JimmyJames Good to know - just assumed they were states, like in Australia and the USA. I see that edits have been made to correct this.
    – bob1
    Commented May 2 at 23:07
  • @bob1 Canada has 10 provinces and three territories (Northwest Territories, also known as Bob; Yukon and Nunavut). Australia has six states and two territories (Northern Territory and the Australian Capital Territory). The USA has 50 states and five territories. Not to forget the tribal nations. And don't get me started on the UK...
    – AlDante
    Commented May 2 at 23:25

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.