Sonoran Desert Toad

During the summer monsoon season, Sonoran Desert Toads (Bufo alvarius) are common, nocturnal visitors to yards near water or natural, desert vegetation here in the Sonoran Desert. They emerge after the summer rains in order to feed and breed in large, temporary rain pools. During the rest of the year, Sonoran Desert Toads hibernate underground. These huge toads like to gorge on insects, especially June Beetles, near outdoor lights or lighted windows and doors. Male Sonoran Desert Toads will also get into swimming pools and then call to attract females. Since they are usually unable to escape from the swimming pool, the Sonoran Desert Toads can be found the next morning, usually still alive, sitting grumpily inside the pool filter compartment waiting to be rescued.

Determined and persistent, Sonoran Desert Toads are surprisingly difficult to keep out of your yard because they can squeeze under gates, and I've even observed these wily toads climbing both wire fences and wire mesh snake guards. No matter what I do to keep them out, I still find these toads in my Tucson, Arizona yard every summer. I spotted this greenish Sonoran Desert Toad in my yard in early August of 2007.

Sonoran Desert Toad (Bufo alvarius)

Sonoran Desert Toads were formerly known as Colorado River Toads, but these large toads are not only found near the southern Colorado River, but also in desert areas (mostly in the Sonoran Desert) from southeastern California, northern Mexico, and through southern Arizona to western New Mexico.

Sonoran Desert Toads are olive green to brown in color and have lumpy skin, large glandular lumps on their hind legs, golden eyes with horizontally elliptical pupils, large, poison-filled parotoid glands behind their eye and tympanum (circular external ear), and one or more distinctive white tubercles at the corners of their mouth. Sonoran Desert Toads can be up to 7 1/2 inches (19 cm) long, and they are the largest toad found here in Arizona (the even larger Cane Toads (Bufo marinus) aren't found here). If they have been gorging on a plentiful supply of nocturnal insects, Sonoran Desert Toads can become amazingly fat as well.

With their large size and frequent habit of sitting nonchalantly out in the open as they wait for something edible to happen by, Sonoran Desert Toads might seem to be an easy target for predators, but these large, slow toads are very well defended. If picked up or mouthed by a predator, Sonoran Desert Toads will exude a potent, milky white toxin from their parotoid glands. If ingested, their toxin is capable of seriously sickening or killing potential predators.

Dogs are at especial risk from Sonoran Desert Toads and can quickly exhibit potentially fatal symptoms of toad poisoning (excessive salivation or foaming at the mouth, head shaking, red or irritated gums, drunken gait, confusion, weakness or complete collapse, heart arrhythmia, vomiting, diarrhea, and pawing at the mouth). Seizures and death can occur in dogs within 30 minutes from a Sonoran Desert Toad poisoning. Once toad poisoning symptoms appear, emergency veterinary care is needed, but if you observe your dog with a Sonoran Desert Toad, immediate first aid can help prevent toad poisoning from occurring in the first place:

Sonoran Desert Toad (Bufo alvarius) First Aid for Dogs

  1. Turn on the garden hose (or other water source) to get a small but steady, gentle flow. Too high a flow can cause your dog to choke or swallow water. Too low a flow (a mere trickle) would be ineffective.
  2. Hold your dog's mouth open with its nose pointed downward to prevent water from going down its throat.
  3. Put the hose up to the back corner of the dog's mouth and direct the water flow forward towards the front of the mouth. Having the water flow out of the front of the mouth is very important because you don't want your dog swallowing or inhaling any of the water. Rub the dog's gums and wipe off its nose to help remove any toxic slime.
  4. Depending on your dog's exposure, continue rinsing its mouth for up to 10 to 15 minutes.
  5. If you are unable to immediately and thoroughly rinse out your dog's mouth, if your dog has eaten all or part of one of these toads and/or swallowed the toxin, or if your dog still exhibits any toad poisoning symptoms after washing its mouth, seek immediate, emergency veterinary care!

My Labrador Retriever Sammy has had this emergency at-home mouth washing several times because he just can't leave these devious, yard-invading toads alone. One evening in early August of 2007, I found Sammy playing with this brownish Sonoran Desert Toad below, and Sammy got a nice, long mouth-washing as a result. As you can see, the toad was unharmed and seemed quite unfazed by the encounter.

Sonoran Desert Toad (Bufo alvarius)

Tall, smooth-sided walls and fences and solid gates with no toad-sized gaps under them can keep Sonoran Desert Toads out of your yard, but these amazing toads can easily climb wire mesh on fences or gates and slip through any rodent-dug holes under fences. These toads are very hard to keep out of your yard if you have chain-link or wrought iron fences or gates like I do, so the best thing to do in this situation is to keep your dog inside after dark and supervise it when it is let out at night.

Sonoran Desert Toad toxin is not just toxic, it is also hallucinogenic and contains large amounts of the potent hallucinogen 5-methoxy-N,N-dimethyl-tryptamine (5-MeO-DMT). Since their toxin is poisonous to humans if ingested (which includes toad licking), psychedelic drug users will milk the toads' poison glands, dry the toxin, and then smoke tiny amounts of it, which supposedly makes it less toxic. For an interesting discussion of the possible traditional use of these toads as a ritual intoxicant as well as the authors' self-experimentation with smoking Sonoran Desert Toad toxin, check out the following paper by Dr. Andrew Weil and Dr. Wade Davis:

Weil AT, Davis W: Bufo alvarius: a potent hallucinogen of animal origin. Journal of Ethnopharmacology 1994; 41: 1-8.

Unfortunately for the poor toads, not only does toxin milking cause them stress, it also leaves them temporarily defenseless against predators. Despite their toxicity, Sonoran Desert Toads are very beneficial to have around because of the amazing volume of insects that they consume, and if you don't have outdoor pets or a swimming pool, these toads are nice to have around on bug-filled summer evenings. Because of my dogs and pool, I have to remove all Sonoran Desert Toads from my yard (using a net and a bucket), and as a result of their absence, I have to deal with swarms of beetles and disgusting Kissing Bugs when I go outside at night during the summer.

Update and warning: Check your yard for these toads when you let your dogs outside first thing in the morning and not just at night!

In September of 2007, my Golden Retriever Solomon found a huge Sonoran Desert Toad on my patio one morning, and unfortunately he had been playing with the toad and even chewing on it for some time before being discovered. We took the toad away from him and gave him an immediate mouth-washing, but it was far too late by then. Solomon was already showing poisoning symptoms, so we had to rush him to the emergency veterinarian. Even though Solomon is a very large dog, the toad poison powerfully affected him. Solomon quickly collapsed, losing muscular, bowel, and bladder control. He was screaming in pain and frothing at the mouth, and he had rapidly developed a raging fever. Solomon was in a truly wretched state by the time we reached the vet, but thankfully he rapidly recovered completely with treatment and was even able to go home with us that morning.

The vet told me that most dogs never learn from a toad poisoning experience (they've had repeat patients), so Solomon could foolishly go after one of these toads again. Poor Solomon, he's had three, very unexpected morning incidents with our Sonoran Desert wildlife. Besides the strange daytime Sonoran Desert Toad, Solomon was also bitten by an insectivorous bat that was swimming around in his water dish one morning (it tested negative for rabies), and on another morning, I barely managed to scoop a slowly swimming Gila Monster (Heloderma suspectum) out of my swimming pool just as Solomon tried to retrieve it. One morning incident like this could be a fluke, but three likely make it a pattern… To keep your pets safe, check your backyard for dangerous nocturnal creatures not just at night, but first thing in the morning as well!