Toads are common amphibians found in diverse environments. They can pose risks to humans and pets, primarily from two sources: naturally produced chemical defenses and the potential to carry infectious agents.
Toad-Specific Toxins
Many toad species possess potent chemical defenses, primarily secreted from glands in their skin, most notably the large parotoid glands located behind their eyes. These secretions contain a complex mixture of compounds, including bufotenin and bufogenins, which are natural toxins used for defense against predators. When ingested or absorbed, these toxins can irritate mucous membranes and affect an animal’s heart and nervous system.
In pets, particularly dogs, common symptoms of toad poisoning can appear rapidly, including excessive drooling, foaming at the mouth, pawing at the face, and vomiting. More severe reactions may involve disorientation, muscle tremors, seizures, collapse, and changes in heart rhythm, which can be life-threatening. For humans, contact with these toxins can cause skin irritation, and if ingested, symptoms like nausea, vomiting, dizziness, or chest pain might occur. The severity of the reaction depends on the toad species involved and the amount of toxin exposure, with species like the Cane Toad (Rhinella marina) and the Colorado River Toad (Incilius alvarius) known for their highly potent secretions.
Pathogens Carried by Toads
Beyond their chemical defenses, toads can act as carriers for infectious agents, specifically bacteria like Salmonella. Like many other amphibians and reptiles, toads can harbor Salmonella bacteria in their digestive tracts without exhibiting any signs of illness themselves. Transmission to humans or pets typically occurs through indirect contact, such as touching toad feces or surfaces contaminated by the bacteria, and then inadvertently transferring the bacteria to the mouth.
Symptoms of Salmonella infection in humans usually include stomach cramps, diarrhea, fever, and nausea. While most healthy individuals recover, infants, young children, pregnant women, the elderly, and those with compromised immune systems face a higher risk of developing severe illness.
Safe Interactions and Prevention
Minimizing risks associated with toads involves implementing practical preventative measures. Thorough handwashing with soap and water is important after any contact with toads, their habitats, or anything they may have touched. Pet owners should supervise their animals, especially dogs, to prevent them from mouthing or ingesting toads, particularly in areas where highly toxic species are prevalent.
To make your yard less attractive to toads, consider removing standing water sources, managing insect populations, trimming dense vegetation, and avoiding leaving pet food bowls outdoors. It is also advisable to teach children not to handle wild animals, including toads, to prevent accidental exposure. If a pet shows symptoms like excessive drooling, seizures, or collapse after toad contact, immediate veterinary attention is important. For humans, if symptoms such as vomiting, dizziness, or chest pain develop after contact, medical attention should be sought.