Almost all spiders are venomous, although they rarely transmit communicable diseases to humans. Most spiders have mouthparts too small to penetrate our pet’s skin and are therefore harmless to them. But three groups of North American spiders can harm our pets: widows, recluses, and tarantulas.
- Widows: Found throughout the United States, widow spiders bite when accidental contact occurs. A bite from the most common black widow spider is dangerous for your companion animal, causing pain, and within 30 minutes to 2 hours, fever, weakness, and extreme excitability. Seizures, shock, and even death can result. Widows are most often found inside homes, garages, and sheds.
- Recluses: Brown recluse spiders are abundant and active at night during the warmer months, most commonly in the Midwest and Southeast. Curious companion animals are the most likely to be bitten because these spiders will not bite unless rousted from their hiding places: dry, undisturbed closets, basements, or attics. Initially painless, the bite becomes painful because the venom destroys red blood cells and kills surrounding tissue. The extent of the damage depends on how much venom is injected. Although bites are rarely fatal, they can cause kidney failure if your pet has a poor immune response. Like widows, recluses are found indoors and inside of garages and sheds.
- Tarantulas: Tarantulas are Southwest natives but are found as far east as the Mississippi River and as far north as Arkansas. In addition, some people keep tarantulas as household pets. Tarantulas should not be kept with other pets because, as a defense mechanism, a tarantula may drop the fine hairs from its abdomen. When hairs contact unprotected skin, allergic reactions may result. More worrisome, the bite of the tarantula can be fatal to dogs or cats. Tarantulas dig burrows out of doors for rest and egg-laying.
To reduce the risk of being bitten by spiders inside your home, make sure to tightly seal stored items. In addition, keep your home uncluttered so that you can easily use a vacuum cleaner to remove spiders, webs, and egg sacs, as well as insects providing spider food. Give careful attention to dark corners, especially behind and under furniture.
Outside, seal windows and doors to ensure that spiders or their insect prey cannot enter your home. Remove any stacks of wood as well. Consider using a flea and tick fogger in little-used outbuildings and garages. In addition, you may wish to use a home flea control spray like the Adams Flea & Tick Home Spray.