Unlike snake bites spider envenomation of horses is very poorly described. In Australia the most venous spiders, in decreasing order of severity, are the Sydney Funnel-Web, Other Funnel-Web spiders, the Redback spider, the Mouse spider, the White-Tailed spider, the Australian Tarantula, Recluse spiders, the Huntsman, and the Garden Orb spider. In North America the venomous spiders of concern, again in descending order of clinical importance, are the Recluse spider, Black Widow spider, the Brown Widow spider, Red Widow spider, Yellow Sac Spider, Six-eyed Sand spider, the Wolf spider and the Tarantula.
The Sydney Funnel-Web spider is the most deadly spider to humans in Australia, with more than a dozen reported deaths. That spider is geographically limited to the Sydney region, from Newcastle to Illawarra. There is a commercial antivenom available, which also covers other less toxic Funnel-Web spider bites. No other antivenoms are available in Australia.
Perhaps the most suspected spider of importance in Australian horses is the White-Tailed spider. They are found across most of southern mainland Australia and Tasmania. It is often blamed for causing limb swelling with skin necrosis and secondary cellulitis. Proving an association is extremely difficult.
Tags: Toxicities