From July 15 through Sept. 30, the monsoon season means heavy rains, which tend to bring an influx of toads and frogs into Phoenix yards adjacent to the mountain preserves and other undeveloped areas.

While they may seem like a seasonal annoyance, many of these toads are toxic and exposure to them—if not treated immediately—can be lethal to family pets, according to Dr. Billy Griswold, director of medical management at Emergency Animal Clinic (http://eac-az.com), which has five hospitals throughout the Phoenix metro area.

A study by Veterinary Pet Insurance found that toad poisoning is one of the 10 most common sources of pet poisoning, resulting in hundreds of cases—mostly involving dogs—every year.

According to the Arizona-Sonora Desert Museum, at 7 inches or more the Sonoran Desert Toad (Bufo alvarius) is one of the largest toads native to North America. Adults have a uniformly green to greenish-gray topside of the body and creamy white underside.

This toad is common in the Sonoran Desert, and it is mostly found in undisturbed desert areas that feature creosote bush desertscrub and thornscrub, although it also enjoys grasslands up into oak-pine woodlands.

Sonoran Desert toads have extremely potent, defensive toxins that are released from several glands in the skin. Dog owners should be cautious: the toxins are strong enough to kill full-grown dogs that pick up or mouth the toads. Symptoms of intoxication are excessive salivation, irregular heartbeat and gait, and pawing at the mouth.

If a dog displays any of these symptoms, use a garden hose to rinse its mouth from back to front and consult a veterinarian.

Remember that contact doesn’t have to be direct. A toad perching on your pet’s water dish can leave behind trace levels of toxin strong enough to endanger your four-legged friend. During the monsoon season, don’t leave your pet’s food or water bowls outside where toads can climb in.