Azalea Poisoning in Dogs

Azaleas are a flowering shrub, closely related to the Rhododendron family of plants. It contains the potent neurotoxin grayanotoxin which can disrupt the ability of the cells of the body to return to their normal state after excitation. When ingested they can interfere with skeletal and nerve functions as well as hinder the action of the heart muscle. Abnormal heart rhythms, tremors, and low blood pressure are three of the signs of Azalea poisoning that can lead to serious health issues. If your pet has sampled any part of an Azalea plant, it is imperative that you contact your veterinarian immediately.

The flowering shrub Azalea contains a powerful neurotoxin called grayanotoxin which can disturb the proper function of the body’s cell membranes. Azalea poisoning should be treated as an emergency.

Symptoms generally are initiated within just a few hours after ingestion. The toxic dose of this plant is approximately 0.2% of the animal’s weight. This means that eating as little as two ounces of plant material may cause serious clinical signs to develop in a 60lb dog. 

•  Abdominal pain
• Abnormal heart rate  
• Abnormal heart rhythms
• Coma
• Depression
• Diarrhea
• Excessive drooling
• Hypotension
• Lethargy
• Loss of appetite
• Low blood pressure
• Muscle weakness
• Rapid, shallow breathing
• Seizures
• Temporary blindness
• Tremors        
• Vomiting
• Weakness

 Types

These are types of Azaleas that grow natively in America: 

Rhododendron occidentale

• Mainly found in southern Oregon and northwestern California
• The flowers on this variety are larger than the flowers on the other varieties and either white with a spot of yellow or yellow overall

Rhododendron arborescens

• Mainly found growing wild from Alabama to Pennsylvania
• This variety has a fragrance that is very close to the fragrance of heliotrope
• The flowers are generally white or pale pink, although they may have a yellow flare 

Rhododendron calendulaceum (Flame Azalea)

• These are found growing in the mountainous areas of the southeastern part of the country
• An azalea plant with vivid yellow, orange or red flower but unlike the other Azaleas native to North America, it has no fragrance

The toxicity of the Azalea lies in the neurotoxin that it contains, called grayanotoxin. The toxin is located in the leaves, petals and even pollen of the Azalea bush. The grayanotoxin contained in the Azalea plant has properties that closely resemble turpentine and will cause some burning in the mouth when it is chewed. Once inside the body this chemical binds to the sodium channels in the cell membranes, which disrupts the natural electrical current present in the cells preventing them from returning to their normal state. This reaction leaves the cells in a permanently excited state.

If you see your pet consuming any part of the Azalea bush, identification is often all that is required for diagnosing the origin of your dog’s distress. A sample of the plant that was consumed will assist in confirming that diagnosis and a biochemistry profile, complete blood count, and urinalysis are likely to be completed at this time as well as a full physical examination. 

If the ingestion of the plant was not witnessed, your veterinarian will take special note of any opportunistic eating that was witnessed or suspected, in addition to any concurrent prescriptions or supplements that your dog is taking in an attempt to reveal toxins or drug interactions that may be the cause of the symptoms. In some cases, honey can become infused with pollen that bees have gathered either from Azaleas or their close relatives, Rhododendron, and your pet may be affected if they consume any of this “mad honey”.

Preliminary treatment will depend on how long it has been since the flower was ingested and if any symptoms have commenced, but in most cases your dog will be admitted to the veterinary hospital for treatment right away. If the Azalea plant was consumed recently and if there are no symptoms showing as of yet, vomiting will most likely be induced to prevent the absorption of the grayanotoxin into the bloodstream. 

Activated charcoal will also be will be given to the patient in an attempt to soak up as much of the toxin as possible. If it has been a longer period of time, the veterinarian may choose to perform a gastric lavage under general anesthetic and to remove as much toxin from the patient’s stomach as possible. The supportive treatment is likely to include IV fluids for dehydration and combinations of electrolytes and sugars to adjust for any imbalances. Respiratory support may be needed and atropine may also be required if the canine’s heart rate drops below 40-50 beats per minute.

Recovery from mild Azalea poisoning is usually within about 24 hours, however, larger doses or extreme reactions may extend the recovery time. Ensuring that the recovering patient has a quiet and calm environment to return home to will help speed recovery. Plenty of fresh water should be made available and extra bathroom breaks should be expected as toxins and medications make their way through the digestive system. 

Patients that are recovering from anesthesia for gastric lavage may also have coordination difficulties when they first get home, and they are often confused and disoriented. Isolation from other pets and from children is generally advised until the medication has fully cleared your companion’s system. Your veterinarian may recommend more frequent monitoring of your pet’s blood chemistry levels, particularly in relation to kidney and liver functionality or impairment.

Paying to treat azalea poisoning out of pocket can be a major financial burden. Fortunately, most pet insurance companies reimburse claims within 3 days, putting 90% of the bill back in your pocket. In the market for pet insurance? Compare leading pet insurance companies to find the right plan for your pet.