RHODEDENDRON

Morphology They are characterised by shrubs and small to (rarely) large trees The leaves are spirally arranged. Leaf size a can range from 1-2cm to over 50cm They can be either evergreen or decidious. The flowers are arranged in many clusters.

Toxicology Some species are poisonous to grazing animals Produce a toxin known as grayanotoxin in their pollen and necter This disrupts sodium channels affecting the skeletal and cardiac muscles If eaten via honey it has a slight hallucinogenic and laxative effect. Is extremely toxic to horses Some animals die within a few hours of digesting the plant. Most horses tend to avoid it As little as 3ml nectar/kg bodyweight or 0.2% of the bodyweight of leaves may be toxic or lethal

Signs and Symptoms Drooling Vomitting Diarrhoea Inappetince Abdominal pain Abnormal heart rate and rhythms Hypotention Weakness Tremours Depression Blindness Seizures Coma

Treatment Emesis is used where appropriate Activated charcoal should be administered repeatedly the first day Fluid replacement therapy and respiratory support may be necessary. Atropine is recommended for severe bradycardia. Isoproterenol or sodium channel blockers may be used to treat the heart block