It is amazing to me as I go about showing homes how few people seem to be aware of the fact that Oleanders are highly poisonous to both humans and animals.  They are found all over here in Tucson, AZ, most likely because they grow quickly and are quite hardy.  Of course you have to ingest the leaves and/or branches of the plant to be poisoned, but that is a likely scenario if you're dealing with toddlers or small animals.

Oleander poisoning affects both the digestive system and the cardiac system, oftentimes leading to death.  The poison is so potent that it is able to kill horses.  I recommend using other shrubbery to decorate your landscape, but if you choose to use Oleanders be advised of their toxicity.

For information on common poisonous plants, click here:  http://plantanswers.tamu.edu/publications/poison/poison.html