How to Treat Spider Bites on Dogs and Cats


Most spider bites are harmless, sometimes causing itchiness, minor pain, swelling and redness. However, two species of spiders in North America are dangerous to both humans and pets: the black widow and the brown recluse. The venom delivered by a bite from these spiders can cause serious side effects and require medical attention.

Neurotoxins in the female black widow's venom directly affects the nervous system, causing muscle spasms and, potentially, paralysis. Small dogs and cats, especially, are at risk of experiencing serious symptoms from a black widow bite.

A brown recluse's venom is hemotoxic, destroying red blood cells and causing local tissue damage. Instead of affecting the nervous system, it affects the skin and tissue around the bite. Sometimes, a brown recluse bite will look like a bullseye—white in the center with redness around it. These bites are not always painful and symptoms start with itchiness. However, the venom can eventually cause a serious wound requiring treatment by a veterinarian.

Look for the following symptoms that your dog or cat has been bitten by a spider:

  1. Limping or holding one leg off of the floor

  2. Swelling, redness or frequent scratching

  3. "Bulls Eye" mark or blister

  4. Weakness, lethargy or increased heart rate

  5. Diarrhea or vomiting

How to Treat Spider Bites on Dogs and Cats

If you suspect that your dog or cat has a spider bite, calling your veterinarian is the best first step. Describe the symptoms you're seeing and how long it's been since you first noticed them. The vet can suggest what to do next in terms of treatment and care. They might also be able to tell you that it's nothing to worry about.

If you're lucky enough to see the spider that bit your pet, capturing it in a jar or other container will let the vet identify it easily and choose the best treatment. If you're worried it's a dangerous spider, try to take a picture of it. Of course, you might not know your pet has been bitten until hours later. Then, the vet will try to identify the bite based on its appearance and symptoms.

Depending on the type of bite, your pet might be treated with an antivenin (a.k.a "antivenom"), IV fluids, cleaning solutions, pain medications or antibiotics. Ice packs can help reduce swelling and irritation. Try to prevent your dog or cat from licking or scratching the bite excessively.

How Quickly Do Pets Recover from Spider Bites?

"Dry" (nonvenomous) bites can heal in as few as two or three weeks. Even some venomous bites will heal within a month. The most severe bites from brown recluses or black widows can take much longer. With ongoing treatment, your pet can recover fully from these bites in a few months.

How to Prevent Spider Bites on Your Pets

Don't put your pets and family at risk of spider bites. Whether you've seen webs in your home or seen a spider on the porch, call the professionals at Aptive for a custom pest control solution. Our experts use eco-friendly, pet-friendly techniques to protect your home from spiders and other pests.

Call Aptive Environmental today for a free quote and to schedule your first appointment.