The Animal Health Veterinary Laboratory Agency (VLA) investigation of this outbreak included post-mortem examinations and an immediate farm visit. Botulism was suspected on clinical grounds.

In this case it was not possible to confirm the diagnosis with botulinum toxin testing, and there was no link with poultry litter, which is the commonest source of the toxin.

The putative source in this case was the carcase of a small mammal or bird that became incorporated in a single batch of feed mixed on the farm. Voluntary restrictions placed on the farm protected the food chain, and vaccination of the whole herd prevented further losses.

Further info on botulism can be found here.