Skip to main content

If your dog ate an oleander flower, you are right to be concerned. The oleander plant is considered so poisonous that even the mere fact of a dog drinking water from a vase where a flower was soaked in can turn out being problematic. Veterinarian Dr. Ivana shares some first aid tips and information for dogs who have ingested an oleander flower. 

Are Oleander Flowers Toxic to Dogs?

Nerium oleander is an exceptionally beautiful ornamental plant that can grow over 6 feet in height. It blooms during the summer and is frequently found along roadsides. Its beauty and resilience to poor growing conditions (bad soil, lack of water and strong winds) make it a highly popular garden plant. Sadly, the popular oleander flower is extremely toxic to many animals, including dogs.

Dogs, cats, rabbits, horses, cattle, sheep and goats are all sensitive to the oleander’s toxic effects. However, due to the flower’s distribution and the dog’s willingness to eat just about anything, the most commonly affected animal species is the dog. Given the opportunity, a dog will munch on anything, including the highly toxic oleander flower.

Basically, all parts of the oleander plant have toxic properties – that includes the roots, stems, narrow, lancet-shaped leaves, fruit, nectar, sap and seeds. It should be noted that the toxin concentration is highest in the roots and stems. However, the leaves and flowers are most likely to be ingested. As mentioned, even vase water holding oleander plants gains toxic components over time.

Signs of Oleander Toxicity in Dogs 

Oleander contains over 30 different types of glycosides. However, the most important toxin is a glycoside known as oleandrin. The oleandrin is similar to the drug digitoxin used for heart failure management. The oleandrin acts by affecting the gastrointestinal, cardiovascular and central nervous systems.

The exact lethal dose is not determined. According to reports it takes about 20 to 30 oleander leaves to kill a grown horse. There are no proven scientific data regarding the lethal dose in dogs. 

A dog intoxicated with oleander flowers will show the following signs and symptoms:

  • Gastrointestinal upset manifested with excessive drooling, projectile vomiting and profuse diarrhea
  • Nausea and drowsiness
  • Dilated pupils
  • Abdominal pain
  • Impaired heart functioning – a plethora of issues ranging from bradycardia (decreased heart rate) and tachycardia (increased heart rate) to premature heart beats and AV blocks
  • Quivering of the heart (fibrillation)
  • Changes in the blood pressure – based on the phase, either hypotension (low blood pressure) or hypertension (high blood pressure)
  • Neurological issues – ataxia (lack of coordination), tremors, seizures, lethargy and depression
  • Inability to stand, weakness and disorientation
  • Dehydration
  • Shock.

In most cases, it takes around 3 hours for the clinical signs to develop. However, this depends greatly on the dog’s size and the amount of ingested oleander flower. 

If you suspect your dog ate oleander or actually saw it munching on this plant – rush your dog at the nearest vet clinic.

At the Vet's Office 

The vet will perform a thorough physical examination while discussing with you the time of the incident as well as the amount of plant ingested. Knowing these two factors will help the vet make a better assessment of the condition.

Sadly, there are no specific tests for diagnosing oleander intoxication. However, the vet may conclude what is going on based on the patient’s history and clinical manifestation.

To assess the severity of the intoxication, the vet will order some blood analysis. The most common findings include:

  •  Hyperkalemia – increased levels of potassium in the blood
  •  Hypoglycemia – decreased levels of sugar in the blood
  • Electrolyte abnormalities – due to poor perfusion and gastrointestinal symptoms
  • Hemoconcentration – thickening of the blood as a result of dehydration caused by the profuse vomiting and diarrhea.
Scroll to Continue

Discover More


Do Dogs Act Out of Spite? Here's What Science Says

Whether dogs act out of spite is an important question considering that spiteful behavior can put a big dent in your relationship with your dog. If your dog appears to pee, poop or destroy things out of spite, this is article is ultimately for you.


What Does it Mean for a Dog to "Honor The Point?"

A dog honoring the point, may sound like something quite complex, but in the world of hunting dogs, this term is quite popular. Discover what honoring means in dogs and the importance of a dog honoring another dog's point.

Screenshot 2022-06-24 152828

Examples of Stereotypical Behaviors in Dogs

If you are looking for examples of stereotypical behaviors in dogs, most likely you have heard about stereotypies and are looking for some concrete explanations. Discover in layman terms what stereotypies are in dogs along with several examples.

The vet is likely to order an electrocardiogram to evaluate the dog's heart function. If necessary, based on the actual manifestation, the vet may suggest some additional diagnostic tests and procedures.

Did you know? According to Colorado State University, red flowered varieties of oleander appear to be more toxic. 

Treating Oleander Toxicity in Dogs 

The treatment strategy depends on the patient’s status. If the intoxication occurred shortly before (usually no more than three hours ago) and the patient has not developed signs of intoxication yet, the dog is considered to be an asymptomatic patient.

On the flip side, if there are already visible signs, the patient is labeled as symptomatic and more aggressive treatment approach is warranted.

Treatment of Asymptomatic Dogs 

Treating the asymptomatic dog includes several steps to prevent or at least minimize absorption of oleandrin. 

  • Vomiting induction – if you have not done this at home (per your vet’s suggestion), the vet will induce vomiting by administering certain drugs. Vomiting is important because it eliminates the plant material from the stomach, thus decreasing the risk of triggering more serious complications.
  • Administration of activated charcoal – to absorb the remaining toxins. The activated charcoal can be administered several times, especially if larger amounts were ingested.

Treatment of Symptomatic Dogs 

Treating the symptomatic dog requires several steps:

  • Intravenous administration of fluids with balanced electrolyte contents (low in calcium and potassium) – the goals of the IV fluids are to rehydrate the organism, support the cardiovascular system and basically, flush out the poison.
  •  Administration of the specific antagonist – Digibind (if possible, since it is rarely available and comes with a hefty price tag).
  • Symptomatic treatment and supportive care which can include the following
  • Anti-emetics to stop vomiting– if the dog has vomiting urges while nothing left to actually expel.
  •  Atropine or lidocaine to control the heart abnormalities such as bradycardia and tachyarrhythmia respectively.
  •  Benzodiazepines – to control the seizures.
  •  Sodium bicarbonate – to control the potassium levels in the blood.
  •  Dextrose – to control the blood sugar levels.

Costs of Treating a Dog With Oleander Toxicity

Having your beloved dog treated due to oleander intoxication will set you back roughly between $500 and $6000. The average cost of the treatment is $4,000, but the exact cost varies depending on the severity of the intoxication and location.

Prognosis of Oleander Toxicity in Dogs

Dogs that received prompt and aggressive treatment have better chances of surviving. More often than not, the recovery period lasts several days during which the dog needs to be hospitalized and closely monitored.

Preventing Future Accidents 

To prevent oleander-related accidents, limit your dog’s exposure to this plant. Do not plant this flower in your garden or any place your dog has free access to. 

If walking your dog in an area where wild oleanders grow, keep him on a short leash and avoid close contacts with the flower. If you were keeping oleander flowers in an out-of-reach place, dispose them safely after drying up. 

About the Author 

Dr. Ivana Crnec is a graduate of the University Sv. Kliment Ohridski’s Faculty of Veterinary Medicine in Bitola, Republic of Macedonia.


Related Articles