Ovine Plant Poisoning

January is the most common month for deaths due to plant poisoning to be diagnosed in sheep therefore something to look out for in the next few weeks (figure 1). 

Occasionally animals present with signs of abdominal pain, bruxism and regurgitation but more often are found dead suddenly. Poor grass availability and snowfall in winter months are likely to encourage animals to stray and seek alternative forage.  Sheep that are wintered away on other holdings should be kept from straying by ensuring fencing is secure and supplementary forage provided if snow cover remains.    

Ovine plant poisoning
Figure 1 – Cases of ovine plant poisonings by month


Rhododendron and its relative Pieris (figure 2) are the most common causes of plant toxicity.  Cases of bracken, oak and ragwort poisoning are sporadic and tend to be more chronic in nature.  Post mortem examination is the diagnostic method of choice and can easily be carried both on farm or at a post mortem centre.  Discovery of even a few leaves of a known poisonous plant in the rumen is diagnostic.  Please get in touch to let us know about cases and for support where further testing may be necessary.

Pieris sp leaves
Figure 2 – Pieris sp leaves

Posted by Veterinary Services on 22/01/2021