The presence of large, unfamiliar toads in a yard or neighborhood can be alarming, particularly for pet owners and parents. These amphibians, commonly but incorrectly grouped under the historical name “Bufo toad,” secrete a potent defensive toxin that can be dangerous when mouthed by a curious dog or cat. Understanding how to distinguish these specific species from harmless native toads is critical for ensuring the safety of household pets and small children. Accurate field identification relies on recognizing distinct physical markers.
Clarifying the “Bufo Toad” Identity
The term “Bufo toad” refers to large, often toxic toads, though the genus Bufo is now considered scientifically outdated for the most concerning species in the United States. The two major toads of concern are the Cane Toad (Rhinella marina or Rhinella horribilis) and the Sonoran Desert Toad (Incilius alvarius). Both species are part of the family Bufonidae, which includes all “true toads.”
The Cane Toad, also called the Marine Toad or Giant Toad, is an invasive species established across much of southern Florida, the Rio Grande Valley in Texas, and in Hawaii. The Sonoran Desert Toad, also known as the Colorado River Toad, is native to the southwestern United States, primarily found in Arizona and New Mexico. While regional distribution provides an initial clue, physical inspection remains the only reliable method for confirmation.
Distinct Physical Identification Markers
The most telling feature of the Cane Toad is its size, as adults often reach between 6 and 9 inches in length, making them significantly larger than most native toads. The skin is typically dry, warty, and ranges from reddish-brown to grayish-brown, sometimes with darker mottling. A primary distinguishing feature is the presence of prominent, massive parotoid glands located behind each eye.
These parotoid glands are large, triangular structures that extend backward over the toad’s shoulders. The Cane Toad lacks the bony ridges, or cranial crests, on the top of its head, though it does have distinct ridges running above the eyes and down the snout. The Sonoran Desert Toad, while also large at up to 7 inches, often displays smoother, greenish-gray skin and possesses similarly large, elongate parotoid glands.
Differentiating from Common Native Toads
Distinguishing the large toxic toads from smaller, harmless native species, such as the Southern Toad (Anaxyrus terrestris) or the American Toad (Anaxyrus americanus), requires comparing specific head and body structures. Size difference is a strong indicator, as native species rarely exceed 4 inches in length, whereas the Cane Toad is often twice that size.
The most reliable comparison lies in the shape and placement of the parotoid glands. Native toads possess glands that are noticeably smaller and typically oval or bean-shaped, unlike the massive, triangular form seen in the Cane Toad. Furthermore, many native toads, including the Southern Toad, have prominent bony ridges, or cranial crests, located on the top of the head between the eyes, a feature entirely absent in the Cane Toad. These crests often look like small, bony “horns” on the head of the native species.
The Importance of Accurate Identification
The parotoid glands of the Cane Toad and the Sonoran Desert Toad secrete a milky-white substance known as bufotoxin. This toxin is rapidly absorbed through the mucous membranes of the mouth, making it dangerous to pets that mouth or bite the toad. Bufotoxin targets the central nervous system and the cardiovascular system, causing symptoms that can appear within minutes of exposure.
Signs of poisoning in pets include profuse drooling or foaming at the mouth, pawing at the face, disorientation, and staggering. Symptoms can quickly escalate to tremors, seizures, and an irregular, elevated heart rate, which can be fatal without prompt treatment. If a pet has contact with one of these toads, the owner must immediately flush the pet’s mouth for at least 30 seconds with a wet cloth or running water, ensuring the head is angled downward so the toxin drains out and is not swallowed. Following this immediate decontamination, veterinary care must be sought to monitor and stabilize the animal’s heart and neurological function.