Poisonous Plants to Know About

As a rule, most poisonous plants are unpalatable to livestock, however a lack of available food, dead or dying plants and the vagaries of individual animal behaviour make an awareness of the common plant poisoning cases we see in Hampshire a useful thing to have on your back pocket.

Rhododendron, Ragwort, Oak & Yew are four of the more common plants we see causing problems, in autumn and winter, as available pasture diminishes. Whilst our basic advice is to keep an eye on pastures, inspect field boundaries and where possible, move animals from fields where there is a danger … it doesn’t hurt to know what to look out for as farmers in the areas around Fordingbridge, Cranborne and Ringwood continue to have problems.

If you think you have a livestock poisoning issue, then please keep our emergency details handy.

Get our emergency details

The main problems we get in this area come from the following four species:


An invasive species that’s now common in gardens across the UK, Rhododendron contains a poison that slows the heart and lowers blood pressure. Stock become weak and are unable to stand, ruminants often bloat up and then vomit. Poisoning is most common when snow cover reduces grazing. If you suspect Rhododendron poisoning call us, as we can treat with anti inflammatory medication and oral re-hydration.


Most common in the autumn and more dangerous to cattle than sheep, the greatest risk to cattle is from Ragwort in preserved forage that can be readily eaten but has lost none of its toxicity. Ragwort ingestion basically damages the liver, but symptoms usually begin to show when it’s eaten over time. This is actually good news (because you have time to spot the plant) as there is no treatment apart from removing the plant from the diet.


More likely after stormy weather when leaves and acorns fall and are eaten by animals. Leaves and acorns contain tannins that can bypass natural protection offered by rumen microbes and go on to damage kidneys and cells. Hard to spot but abdominal distention and the animal lying down are the main symptoms. There is no treatment, so the only option is to remove animals from the danger.


Common in gardens and churchyards, ingestion can lead to rapid death. Again, there is no treatment, so prevention is your only option. Inspect field boundaries and if there is un-movable yew, then be especially vigilant in winter, when heavy snow can cause boughs to sag bringing previously un-reachable branches into play.

There are a couple of other culprits you should beware of too; Bracken, Water dropwort & another plant from the Rhododendron family, Pieris. These tend to be more prevalent in spring and summer as young plants bloom & flourish. So, we’ll come back to those in the Spring.

In the meantime, keep an eye on those field boundaries and keep our emergency details handy.