How to Tell if a Pet has a Spider Bite

By Ben Team

If you're a pet owner, chances are that you're familiar with fleas and ticks and how to get rid of them off your pet, but do you know how to deal with spider bites? These insect bites an be difficult to diagnose with certainty, as they often resemble insect bites, bacterial infections or injuries.

Woman with her dog tender scene
Learning how to diagnose and treat spider bites in your pets is important to keep them healthy.
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According to the Merck Veterinary Manual, pet owners should monitor their pets for symptoms, such as severe muscle cramps, pain, disorientation or partial paralysis, which are commonly associated with dangerous spider bites. Most spiders are harmless, but consult your veterinarian anytime you suspect your pet has sustained a bite, as the venom of some species can cause serious illness or death.

Black Widow Spider
Spiders can bite pets, too! Some like this black widow spider can be fatal.
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Widow Spiders

Five different widow spiders inhabit to the United States, including three different black widow species, one brown widow species and the red widow, </ahref="http:>according to Live Science. The three black widow species are the most medically significant; although small differences between the three species exist, they are all inky-black spiders with bright red abdominal markings, sometimes resembling an hourglass.

Bug Guide reports that black widows are common in woodpiles and outdoor buildings, and under logs, rocks or debris, so be wary of letting your dog roam in areas dusty or cobwebbed areas like these. Black widow venom acts fast and can be fatal to your pet, so you should call your veterinarian immediately to have your pet taken to emergency care if you suspect it is a black widow bite.

Cat laying down
If your cat is behaving abnormally it could be a symptom of a spider bite.
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Brown Recluses

Research at University of California Riverside concludes that the United States is home to six to 10 different recluse species, all of which belong to the genus Loxosceles. Brown recluse spiders are most common in the Midwestern states, as far north as southern Illinois, Indiana, Iowa and Ohio, but they also inhabit the Southern states, from Florida to California.

Dog with a brown recluse bite
Brown recluse bites can be itchy and painful but symptoms should clear after four days. If they don't, you should take your pet to the vet.
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True to their name, brown recluses are secretive, nonaggressive spiders who often live in basements, tunnels and woodpiles. Laypersons regularly misidentify small, brown spiders as brown recluses, based on the observation of a violin-shape marking on their back. To accurately identify a brown recluse, the Merck Veterinary Manual advises you observe the spider has unmarked legs with no hairs or spines, an unmarked abdomen and — most importantly — six eyes, arranged in three pairs.

The experts at Vetary note that while the brown recluse bites look painful, and your pet may experience itching and redness, these symptoms should go away within four days. If they persist, you should take your pet to the vet.

Cocker Spaniel Laying down
To prevent spider bites, avoid letting your pets roam where spiders may be hiding like dark and dusty corners.
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Initial Spider Bite Symptoms

The symptoms caused by spider bites vary widely from one bite to the next, and individual pets respond differently to their venoms. Pet Education describes the first symptoms in dogs and cats commonly experience redness, inflammation, swelling, hair loss or discoloration at the bite site — but many times, bites go unnoticed until systemic symptoms arise. Some of these systemic symptoms include anxiety, muscle weakness, partial paralysis, disorientation and seizures. Dogs and cats often suffer from debilitating muscle cramps after black widow envenomation. Cats are particularly susceptible to black widow venom, and they often begin to drool and exhibit paralysis after suffering a bite. Symptoms progress rapidly.

Cat laying down
Paralysis is a major symptom of a black widow bite in cats.
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Veterinary Measures

Veterinarians largely treat minor spider bites symptomatically and by providing pain medication and supportive care. A typical treatment will involve the veterinarian collecting blood samples and monitoring your pet's progress. However, serious envenomation may require medications to halt muscle contractions, to counteract the necrotizing action of the venom or to reduce blood pressure. The University of California Davis notes that antivenin exists for black widow bites, but it is rarely used in the treatment of bitten pets, largely due to its short shelf life, its high cost and the relative rarity of bites.

Dog with vet
If you suspect your pet has been bitten by a venomous spider, go see a vet immediately for care.
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Avoiding Bites

Hollywood arachnids notwithstanding, spiders are retiring creatures, and not inclined to bite pets or people. Most bites occur from some type of accidental contact, such as when your dog or cat lies down upon the spider, who — fearing for its life — bites in defense. </ahref="http:>We recommend that you prevent your pet from spending time in places where spiders may lurk, such as under porches, in unfinished basements and near woodpiles, to reduce the chances of spider bites.