Lab seizure

While walking in a remote area, my companion and I investigated an old, derelict building. Within 15 minutes his labrador went rigid, all four legs stretched out and his back and neck arched. Sadly, he seizured and died before we could get any help. What do you think happened?

Neil says: Oh dear, how truly horrible. I think it highly likely that you stumbled upon some strychnine, which was once commonly used for killing moles (it could be placed underground where it was hidden from other animals, as was the moles’ horrible death). It was withdrawn from use in 2006, as part of an EU pesticide review. Only small quantities (in the case of a labrador about 22.5mg of strychnine, or 4.5g of the standard 0.5% concentration) can cause twitching, convulsions, seizuring, light, sound and touch sensitivity, followed by the muscle rigidity you described, which is called opisthotonos. There may be periods of relaxation between seizures, but these become less frequent, the pupils are dilated and there is protrusion of the eyeballs due to muscle extension. In contrast to other poisons, there is no salivation and constriction of sphincter muscles means urine and faeces are not passed. Death occurs due to respiratory muscle paralysis and, unfortunately, victims remain conscious right up to that point. There is no antidote and survival is unusual, so there is little that you could have done. It is important that you contact the authorities to enable a clean-up and prevent others being affected.