Araucaria heterophylla, also known as House Pine, Australian Pine, Norfolk Island Pine, and simply Norfolk Pine, the latter being the most commonly used name, is a popular cultivated species of tree. The distinctive appearance of this tree, with its widely spaced branches and symmetrical, triangular outline, has made it a desirable choice for decorative landscaping, use as a houseplant, and display as a living Christmas tree. Large numbers of Norfolk Island Pines are produced annually in South Florida for the houseplant industry. The vast majority of these are shipped to grocery stores, discount retailers, and garden centers during November to be sold as Christmas trees.

The toxic components of the tree are unknown, and the actual danger it poses is somewhat disputed. There is very little documentation regarding the plant’s specific effect on companion animals, and most sources refer to the danger, or lack thereof, that it poses to humans. The IWK Regional Poison Centre in Halifax, Nova Scotia considers the plant to “be safe or non-poisonous,” noting that the only real danger it poses is as a choking hazard to small children. Other sources consider the plant to be mildly toxic and capable of causing localized dermatitis in some individuals when it comes into contact with the skin, as well as gastrointestinal upset if ingested. With pets specifically, the few sources available, many of questionable credibility, state that the “ingestion of pine needles can cause gastrointestinal signs (vomiting, diarrhea) and lethargy.”

As the tree is not a natural food source for any companion animal, it is likely that any number of naturally occurring plant chemicals present in the plant could disagree with the companion animal that chooses to ingest it. This is not a phenomenon unique to this plant specifically, as dogs and cats alike will commonly ingest other plants, grasses, and similar materials, only to promptly vomit them back up.

The greatest danger posed by this plant probably comes from its use as a Christmas tree, in which case it will generally be placed in some sort of stand containing water. That water may accumulate numerous types of bacteria or mold and may even contain chemical fertilizers, preservatives, or other additives, all of which could make a pet very ill. Additionally, it is not uncommon for many retailers to spray any number of potentially harmful chemicals on the tree to extend its longevity or enhance its appearance prior to sale, and those chemicals could inevitably leach into the water.

As with anything that could potentially harm your pet, exercise caution and common sense when this plant is kept in an area where a pet could access it. Ensure your pets have plenty of fresh water available to them to dissuade the urge or need to drink from the Christmas tree stand. If possible, place presents, a screen, or decorative fencing around the tree in such a way as to prevent pets from accessing what, to them, may seem like a perfectly good water source.