Colorado River Toad (aka Sonoran Desert Toad)


Seasonality – summer monsoons (May to August).
Range – small populations in southern California and New Mexico.  Large numbers in the southern half of Arizona.
Time Frame of Exposure– late afternoon to midnight.
Description – large (9 to 18 cm), bumpy, brown toad.



When it rains in the desert, life springs from the ground… literally.  The Colorado River Toad (Bufo alvarius) spends the majority of its life waiting for the rain.  This large toad waits buried in the ground or hiding in rodent burrows.  Because the toad is an amphibian, it requires water in which to lay and fertilize its eggs.  When the summer rains arrive, the toads emerge and hop off, with driven purpose, in search of a mate and a pool of water.  They mostly travel in the cooler night temperatures, and it is then that they are most apt to cross paths with your curious and playful dog.


As might be expected, it is the young dog that is most likely to have an encounter with a Colorado River Toad.  Alive, or even dead, the toad is covered in deadly toxins—heart-stopping digitalis-like compounds and LSD-like hallucinogenic chemicals.  The more the toad is stressed by fear, such as when your canine turns it into a living dog toy, the more of the toxins it secretes.  When the toad is mouthed, those toxins are absorbed into the dog’s system through the mucus membranes. 


The onset of the symptoms—sudden profuse drooling, disorientation, difficulty walking, dilated pupils, seizures, and/or dark-red mucus membranes-- of Colorado River Toad poisoning occur within minutes of oral contact.  Very prompt intervention is the only course that will save the life of the poisoned dog.


Because there is no antidote for the toxins secreted by the Colorado River Toad, a rapid reduction of the toxins ingested is essential to saving the life of the poisoned dog.  The very first measure taken, before absolutely anything else is done, is to flush the exposed dog’s mouth with copious amounts of water for 10 to 15 minutes.  A garden hose works well for this purpose.  For smaller dogs, the water sprayer on the kitchen sink will suffice.  This step is extremely critical.  In the brief time it takes to rush to an emergency veterinary facility, too much toxin can be absorbed resulting in an irreversible and fatal condition.


Once the mouth is well-flushed, the dog should be taken immediately to an emergency veterinary facility.  It is then that further intervention with toxin-absorbing activated charcoal can reduce toxin exposure still more.  In addition, many symptoms of poisoning—irregular heartbeat, seizures and shock-- may be controlled with carefully administered medications.  Well controlled and with the toxins naturally clearing from the system, most patients can respond within one to two hours of the onset of treatment.


Most dogs learn their lesson and do not repeat the Colorado River Toad mouthing experience.  With age comes experience.  Exposure to the toad toxins does not confer any immunity for future exposures.  Vigilance during summer rains for any backyard toads is the best course of preventative medicine for this dangerous condition.