Medical Information Cards N°08. Intoxication by mistletoe and holly

Mistletoe and holly are two plants that are toxic when ingested by a pet. Young animals, especially gamblers, are tempted to chew any plant left within reach.


The mistletoe balls contain a substance called viscotoxin which, several hours after its absorption by an animal, causes various types of disorders: - The irritation caused by the toxin on the digestive mucous membranes (mouth, stomach ...) goes Accompanied by a very large salivation and vomiting. Diarrhea may also be observed a few hours after ingesting the berries.
- Viscotoxin also causes a decrease in blood pressure causing severe hypotension
Finally, nervous disorders can be observed: dilation of the pupils, increased sensitivity of the animal (which reacts excessively to the smallest stimulus), or even abnormal gait (with incoordination in movements and disturbances of equilibrium)

Symptoms vary depending on the ingested dose and the size of the animal. A massive ingestion of mistletoe may be fatal.
There is no antidote to viscotoxin.
If you have seen your pet ingested mistletoe berries or suspected of having swallowed it, go immediately to your veterinarian. If the mistletoe has just been swallowed, the veterinarian will cause it to vomit or gastric lavage in order to reduce the amount of product present in the body. The administration of activated charcoal may also limit the doses of toxin absorbed.
Finally, each symptom will be treated (support of cardiac function, fight against nervous disorders, support of liver and kidney functions ...)

Since the toxicity of the mistletoe is not negligible, you should monitor your pet and ensure that it has no direct access to the plant or berries that may have fallen to the ground.


Like those of mistletoe, holly berries are toxic. Holly leaves also have a certain toxicity but are very rarely ingested because of the presence of quills on their surface.
The symptoms observed following the absorption of holly are those of oral irritation (important salivation), irritation of the digestive tract (vomiting, diarrhea, abdominal pain) and possible nervous disorders if the berries have been ingested Very large quantity.
The toxicity of holly is less important than that of the mistletoe and its absorption is rarely fatal. There is no specific antidote against the poisoning of the holly and the treatment will be, again, symptomatic (antivomitive, antidiarrheal, rehydration ...)

Mistletoe and holly, very present in our homes during these holidays, are toxic to our pets. It is therefore absolutely necessary to prevent any access to these plants to our companions.