Most cases reported to VPIS occur around December – January, when these plants are commonly used as a festive decoration and will therefore be found indoors.
Mistletoe (Viscum album), a.k.a. European mistletoe
Although mistletoe contains toxic compounds, the plant is considered to be of low toxicity. It contains a mixture of toxic alkaline proteins, polypeptide (viscotoxins) and lectins. These toxic proteins are mainly found in the leaves and the stems, but not in the fruit.
With regards to clinical effects, most animals remain asymptomatic but can develop gastrointestinal irritation (hypersalivation, vomiting, diarrhoea, abdominal discomfort) within a few hours of ingestion. Gut decontamination is generally not necessary, unless a huge quantity of plant material has been ingested.
The American mistletoe (Phoradendron tomentosum) is also regarded of low toxicity when ingested in small quantities (e.g. 3 berries, 2 leaves).
Poinsettia (Euphorbia pulcherrima)
Poinsettia has the reputation of being a toxic plant, but this has been greatly exaggerated. It can cause irritation to the mouth and stomach with hypersalivation and sometimes vomiting. Euphorbia species contain three classes of diterpene esters: ingenol (ingenane), daphnane and phorbol (tigliane) which are irritant and cocarcinogenic compounds. However, diterpene esters are thought to be present only in a very low concentration in Euphorbia pulcherrima and as a consequence it isn’t as irritant as other Euphorbia species.
Almost half of VPIS cases in cats and dogs remain asymptomatic. Observed clinical effects in cats and dogs are vomiting, hypersalivation, anorexia, lethargy and depression, with occasional reports of hyperthermia, haematemesis, drowsiness and melaena.
VPIS would recommend symptomatic and supportive care with an anti-emetic and/or rehydration, if required.