The Bufo toad (also known as the Colorado River Toad or Sonoran Desert Toad) secretes a potent toxin that poses a serious danger to pets and, less commonly, humans. Found in specific regions, their venom can cause rapid, severe reactions if encountered. Understanding this toxin and how to respond to exposure is important for individuals living in or visiting affected areas.
Understanding Bufo Toad Toxin
The toxin produced by Bufo toads is a complex mixture of bioactive compounds, including bufotenin, bufogenin, bufotoxin, serotonin, and epinephrine. Bufotoxins and bufadienolides are particularly notable for their cardiotoxic and neurotoxic properties, meaning they can impact both the heart and nervous system.
The milky fluid is secreted from glands located behind the toad’s eyes, known as parotoid glands, as a defense mechanism. When absorbed, these compounds can interfere with various biological targets, such as sodium and calcium channels, and adrenergic receptors. This interference can lead to physiological responses, including cardiac arrhythmias, changes in blood pressure, and respiratory difficulties.
Identifying Bufo Toads and Exposure Risks
Bufo toads are large amphibians, 4 to 9 inches long. They have dry, warty skin that can be reddish-brown to grayish-brown, with a light-yellow or beige belly. A distinguishing feature is the presence of large, triangular poison glands located behind their eyes. Unlike many native toads, Bufo toads lack ridges or crests on the top of their heads.
These toads thrive in warm, wet environments and are commonly found in central and southern Florida, as well as parts of Arizona, Colorado, and Texas. They prefer habitats near water sources like ditches, ponds, and streams, and are most active at night, particularly after rainfall. Pets, especially dogs and cats, are at high risk of exposure when they lick, mouth, or bite these toads, releasing the milky toxin. Human exposure can occur if the toxin comes into contact with eyes, mucous membranes, or open wounds, or if the toad or its eggs are ingested.
Recognizing Symptoms of Toxin Exposure
Symptoms of Bufo toad toxin exposure appear rapidly, often within minutes of contact. In pets, common signs include excessive drooling or foaming at the mouth and pawing at the face. Gums may become red or inflamed. Animals may also show disorientation, head shaking, and vocalization, such as whimpering or crying.
As the toxin spreads, more severe neurological and cardiovascular symptoms can develop. These include weakness, loss of coordination (ataxia), stumbling, or circling. Seizures and convulsions are common, including muscle rigidity and rapid eye movements (nystagmus). The toxin can also cause abnormal heart rhythms (cardiac arrhythmias), difficulty breathing, and in severe cases, collapse or even death, sometimes within minutes to hours if untreated. While less common, human exposure can lead to symptoms such as skin and eye irritation, nausea, vomiting, irregular heartbeat, disorientation, or hallucinations if the toxin is ingested or comes into contact with mucous membranes.
Emergency Response and Treatment
Immediate action is necessary if you suspect your pet has come into contact with a Bufo toad. First, thoroughly rinse your pet’s mouth with running water for 5 to 10 minutes, being careful to direct the water out of the mouth and not down the throat to prevent aspiration. Wiping the gums and tongue with a wet cloth can also help remove unabsorbed toxin.
Following initial rinsing, immediate veterinary attention is advised. There is no specific antidote for Bufo toad toxins, so treatment focuses on managing symptoms and providing supportive care. A veterinarian may administer intravenous fluids to maintain hydration, activated charcoal to help absorb remaining toxins, and medications to control seizures, such as diazepam or phenobarbital. Drugs to correct abnormal heart rhythms (anti-arrhythmic medications) may also be given, and the pet’s heart rate, blood pressure, blood glucose, and body temperature will be closely monitored. For humans, if symptoms are severe or persistent after skin/eye contact, or if ingestion is suspected, immediate medical attention is necessary.
Prevention Strategies
Preventing exposure to Bufo toad toxin involves modifying your yard and supervising pets. Bufo toads are attracted to standing water, so removing sources like overflowing pet water bowls, uncovered swimming pools, or buckets of water can help deter them. Keeping your lawn mowed short and trimming shrubs near the ground reduces hiding spots for toads.
Bringing pet food and water bowls indoors at night is also recommended, as these can attract toads seeking food and moisture. For properties in high-risk areas, installing a solid fence or fine mesh barrier at least 1.5 feet high around the yard, with the bottom buried, can help prevent toads from entering. Supervising pets, especially during their active hours at dawn, dusk, and night, and keeping them on a leash during walks, further reduces the chance of an encounter.