The British Equine Veterinary Association (BEVA) is reminding horse owners to take steps to minimise the risks of Atypical Myopathy. Bare fields and gusty autumn weather can heighten the chances of horses contracting this fatal disease, which is caused by the ingestion of sycamore seeds.

Atypical myopathy is caused by the toxin hypoglycin A. In the UK, the most common source of the toxin is the sycamore tree (Acer pseudoplatanus), a member of the maple tree family.

The most consistent clinical sign of atypical myopathy is the passing of dark brown urine (myoglobinuria) as a result of muscle breakdown. Horses usually become weak and reluctant to move and may lay down, but usually have a normal or increased appetite. In the most severe cases the horse will develop very severe colic-like signs due to significant pain.

Measures to reduce the risk of Atypical Myopathy include identifying trees both in grazed fields as well as those in close proximity. Trees are often easiest to identify in the summer when in full leaf, rather than in the autumn, when leaves have largely fallen. Seeds should be collected or horses excluded from affected areas using electric fencing or stabling.

Owners can call Animal PoisonLine on 01202 509000 for advice if they are concerned their pet has ingested something toxic. We will be able to advise whether the animal needs to see a vet. Veterinary professionals can call VPIS for treatment advice for any poisons case – 020 7305 5055.