Bufo toads- these toads appear in the monsoons months of the summer and seem to pop up after it rains.
They vary in size and can be as large as your hand. They have poison glands that secrete a poison that spreads on their skin. When a dog mouths or licks the toad the poison causes a severe reaction in the mouth fairly quickly. Classic scenario is your dog goes out in the yard and suddenly comes running in with a frantic expression. They may be salivating profusely and pawing at their mouths. The gums can be amazingly bright red.
The immediate treatment is flushing the pets mouth with copious amount of water like a hose on medium pressure.
However, this can be easier said than done. Depending on the character of the pet and their reaction to you intervening while they are in a very frantic state can be unpredictable and dangerous. Many times they will fight the water. Another concern is the possible inhalation of water by a frantic pet and an inexperienced owner who may inadvertently use too much water too fast at a wrong angle.
Some dogs will experience systemic signs such as heat stroke and seizures. Treatment is up to the needs of the patient. Most cases are minor but sadly there is the occasional death.