-----Original Message-----
From: Stephen L. Lindsay, PhD, DVM <slindsay at dmi.net>
To: charless at umich.edu <charless at umich.edu>
Date: Thursday, April 01, 1999 11:54 AM
Subject: Re: house spiders (Hobo Spider?)


>I am a veterinarian in N Idaho and I see a lot of cases of dogs and cats
>that I presume to have been bitten by spiders. This is especially true in
>the fall (Oct-Nov) when I often see several cases a day. With most of the
>animals we never know for sure what happened, but the symptoms match those
>of situations where owners actually see the pet get bit.
>
>The general case profile is of an animal that suddenly becomes listless,
>runs a low-grade fever, may vomit for a day, won't eat or drink much.
After
>a few days they are back to normal, but then a week or more later a
necrotic
>lesion develops. These are nasty with considerable sloughing of skin and
>underlying tissue. They appear as an abscess, but are necrotic rather than
>full of pus. They take a long time to heal. Some animals, especially the
>very old or very young, or animals that get bit inside the mouth, may
>actually suffer liver damage, or may die of toxic shock. Most, however,
>recover fully.
>
>Spider eradication seldom is effective, as many of these cases come from
>households that have regular pest control. It seems that dogs and cats are
>more likely to be down where spiders live, and of course may either attack
>or attempt to play with ones they see running around. I observed one of my
>own cats pick up a spider in his mouth, then collapse from anaphylactic
>shock as soon as he was bit. His case was severe.
>
>In short, there are lots of these spiders out there and most never cause a
>problem, but problems are more likely seen in pets than in people. In
fact,
>lots of these cases get better on their own with no one even realizing what
>has happened. I think that it is, actually, a common cause of pet
illness -
>it is just seldom evaluated by a veterinarian, or is misdiagnosed as an
>abscess or other illness of unknown origin.
>
>Stephen Lindsay
>Coeur d'Alene, Idaho
>slindsay at dmi.net
>
>