Geographic Location:
There are over 200 species of Bufo toad in the world. Below are some of the most common and toxic species of toad and where they can be located.
Bufo marinus (Cane or Marine Toad) located in Florida, Texas, Hawaii and Australia
Bufo alvarius (Colorado River Toad) located in California and Arizona.
Bufo vulgaris located in Europe
Bufo gargarizans located in Asia.
The toad is most active during a period of rainfall, and can usually be seen from dusk to dawn.

Photo courtesy of Bidgee. Bufo marinus (Cane Toad). Darwin, Northern Territory. This photo is licensed under the Creative Commons Attribution 3.0 Unported License. In short: you are free to distribute and modify the file as long as you attribute its author(s) or licensor(s). http://en.wikipedia.org/wiki/File:Young_Bufo_marinus.jpg
Origin:
Toads were introduced into Australia in 1935 to assist in the control of the cane beetle, unfortunately due to the fact that they have no natural enemies to speak of; they have become prolific in some regions and are spreading at an alarming rate. The Cane toad can grow up to 24 cm and the female toad can lay up to 40,000 eggs in one season (per month).
Toad venom is the toads defence mechanism to prevent it being attacked and threatened. The venom is a thick, creamy white, highly irritating substance which is secreted by the glands which are located the back of the toad, behind the eyes, on their dorsum. The venom can also be secreted from the warts located on a toad’s skin.
Poisoning Occurs: Toads do not spit the poison as commonly believed and they don’t bite.
Poisoning usually occurs by contact with an open skin wound, through the venom’s exposure to your pet’s eyes or by mouthing the toad and expressing the glands by pressure.
Toxic Parts: The internal organs of the toad and the venom.
Signs of Toxicity:
The severity of the symptoms depend on a number of factors such as; the extent of the exposure, the time since exposure, and the particular species of toad your pet has been in contact with, the size of the toad (the larger the toad, the larger the glands and therefore the larger amount of venom) and its geographical location (the same species of toad can vary in toxicity due to it’s habitat). Symptoms will also depend on the age of your pet, any underlying diseases or health problems your pet has and the amount of poison ingested in relation to its total body weight.
Gastrointestinal: Frothy drooling, increased salivation (or hyper salivation), vigorous head shaking, pawing at the mouth and retching or the dry heaves. Vomiting can occur and persist for several hours.
In the more venomous amphibians, the following symptoms can result.
Eyes: Many dogs and cats may exhibit a blank or trance like stare.
Respiratory: Difficulty breathing and cyanosis or a blue tinge to the skin and mucous membranes which can be indicative of pulmonary oedema. Depending on the species of toad involved the mucous membranes can also be brick red in colour and look red and inflamed.
Cardiovascular: Abnormal heart rhythms and cardiac arrest.
Central Nervous System: Anxiousness, ataxia or a staggering gait or walk, the animal may also be seen to exhibit signs such as circling, falling, leaning, or stumbling which can lead to prostration and coma. Seizures and death can occur within 15 minutes depending on the species of the toad. Cats may exhibit weakness in their hindquarters.
Toxic Principles: Bufagins, bufagenins, bufotenine, bufotoxins, catecholamines, dopamine, epinephrine, ergosterol, indolealkylamines, norepinephrine and serotonin.
Differential diagnoses: Heat stroke, seizure disorders, other toxins such as metaldehyde (a chemical used to kill slugs and snails), theobromine (found in chocolate or cocoa), insoluable oxalate-containing plants, pyrethrins (natural organic insecticides) and pyrethroids (synthetically made insecticide), oleander and anticholinesterase insecticdes (insecticides which act as a nerve gas or agent). Caustic materials, such as various acid and alkali materials can cause severe hyper salivation and red mucous membranes and should be excluded from the diagnosis.
First Point of Call: There is not specific antidote to toad poisoning. Treatment is usually trying to minimise the absorption of the venom. The first thing to do is to try to remove as much of the toxin from the dog’s mouth as possible, by holding the mouth down and drying it with a paper towel. The mouth should then immediately be flushed with large amounts of water at a slow rate, unless the pet is unconscious or seizing; make sure that you are not flushing the water down the throat but forward or out of it instead – try rinsing the mouth from the side. The flushing should be repeated two to three times for 5 to 10 minutes duration each time. While one person is doing this, another should be phoning the vet to warn them of the occurrence. If the animal is experiencing seizures or the more severe symptoms take them to the nearest veterinarian immediately.
References:
Merck & Co. (2007). The Merck/ Merial Manual for Pet Health. Merck & Co, Inc: USA.
Merck & Co. (2005). The Merck Veterinary Manual. Merck & Co, Inc: USA.
Murphy, M. (1996). A Field Guide to Common Animal Poisons. Iowa State University Press, Iowa.
Peterson, M & Talcott, P. (2006). Small Animal Toxicology (2nd Ed). Elsevier Inc: USA.