Carolyn Baguley explains the precautions to take with holly leaves around lambs.
We’d like to draw your attention to a phenomenon involving lambs and holly leaves, which might be more common than we think.
It seems that three to four week old lambs weighing about 10kg are particularly susceptible to suffocating on holly leaves. If a leaf is ingested stem-first, with the shiny side facing upwards, the downward-facing spines can hook over the edge of the epiglottis (entrance to the larynx) and the upward-facing spines can lodge in the lining of the pharynx (back of the throat).
In this position, the leaf can be neither swallowed nor coughed out, and forms a valve over the entrance to the larynx, causing suffocation. The condition occurs because of a unique combination of the size and shape of the holly leaf, and the size and shape of a young lamb’s pharynx.
The morals of the story are to be careful when allowing lambs access to pastures with holly, to consider the condition in young lambs showing signs of laryngeal disease, and to pay particular attention to the throat area when performing post-mortem examinations on three to four week old lambs.