Rhododendron spp. "Azalea" bushes are extremely dangerous to dogs. Many plants contain toxins that make your dog sick, but the azalea is one of a handful of plants that contain cardiovascular toxins capable of weakening your dog's heartbeat to the point of coma and death. Azalea bushes should be avoided in any garden where the family dogs -- and cats, for that matter -- might eat them.
Azalea's Toxic Compound
If you look underneath the azalea's vibrant colors, you find a plant with leaves and stems full of a toxic principle called "grayantoxin." Grayantoxin is a powerful compound that can poison your dog, cat, horses, goats, sheep and even you. Grayantoxin is found in the nectar of the azalea, and the ASPCA warns that it is so powerful that "ingestion of a few leaves can cause serious problems." It doesn't take much of the dangerous toxin found in the azalea bush to create a potentially fatal health hazard for your dog.
Beyond grayantoxin, what also makes the azalea bush dangerous to dogs is the variety of the plant itself. Azaleas come in about 250 different species, and it is critical that you don't purchase any Rhododendron spp. variety from your nursery, or allow your gardener to plant them in your garden. Always ask a professional to confirm that you are not purchasing a species of the azalea plant (if you are uncertain yourself) to prevent any accidental poisoning. If you must plant azaleas, however, consider placing them in an area your dog cannot get to, or bordering them with something to keep your dog away from the plants.
Symptoms of Azalea Poisoning
Even if your dog normally does not eat your plants, should it decide to nibble on your azaleas for some strange reason, the potential resulting illness is staggering. The ASPCA lists "vomiting, diarrhea, hypersalivation, weakness, coma, hypotension, CNS depression, cardiovascular collapse and death," as all symptoms of azalea poisoning. Grayantoxin interferes with muscle and nerve function within a few hours after your dog has eaten your azalea and, if severe enough, may kill your dog within a few days.
Take Immediate Action
If you suspect your dog has eaten your azalea plant, rush it to the veterinarian immediately; time is of the essence to prevent the long-term damage of grayantoxin poisoning. It is also beneficial to take a portion of your azalea plant with you (if your dog threw up some of the plant, you can take that). Seeing what your dog actually ate helps the veterinarian with the diagnosis and treatment plan. If you require further assistance, the ASPCA has a poison control hotline at 888-426-4435. Please note that a $65 consultation fee may apply to your call, as of the date of this publication.