December 23 - Elaphostrongylus rangiferi

Because Santa's reindeer need to travel at a speed of 650 miles per second in order to deliver all the presents to good little boys and girls, they're going to need to be in peak physical condition. That means that they'd better not be infected with Elaphostrongylus rangiferi, a nematode parasite of reindeer (and also other cervids as well as sheep and goats), commonly known as reindeer brainworm, and closely related to the parasite that causes a similar condition in North American deer, Paraelephaostrongylus tenuis. The eggs of the parasite pass out in the host's feces where they hatch into larvae that either pass into their intermediate hosts, gastropod snails or slugs, or which can remain frozen for periods of up to one year. The worms can cause either a pneumonia-like condition with weakness and coughing or a more serious form of illness that involves neurological symptoms such as confusion and a lack of coordination. This parasite remains a major concern for those raising semi-domesticated reindeer, so Santa better give all of his a thorough physical before he heads out tomorrow night.