If azaleas are toxic, why/how do deer eat them?
Deer browse on a wide variety of plants with varying levels of toxicity. Different animals have different tolerances for plant toxins and the amount they can consume before the toxin causes significant harm. Take a look at the following articles for further information.
http://www.adfg.alaska.gov/index.cfm?adfg=wildlifenews.view_article&articles_id=249 Also, "Researchers have found that animals will eat clay or lick minerals from the soil that tend to buffer or bind to toxins and counteract the harmful effects of plant compounds."