For many of us, just the thought of a spider can send shivers down our spine. But for our canine companions? Well, the sight of one spinning its web might seem like an irresistible invitation to investigate up close … with a big sniff. Oh, the curiosity of dogs! Unfortunately, this could lead to an unwanted spider bite. As responsible pet parents, it’s crucial to understand the risks of spider bites, recognize the common symptoms, and take steps to keep your dog safe from these eight-legged intruders.
Common Spiders that Bite Dogs
Most spider bites won’t cause significant harm to your dog. The venom of most household spiders is either too weak or delivered in such a small quantity that it doesn’t cause a severe reaction. However, there are some spiders whose bites can pose serious risks to dogs. According to VCA Animal Hospitals, “The two groups of spiders responsible for most medically significant spider bites include the widow spiders (Latrodectus spp., including the black widow spider) and the recluse spiders (Loxosceles spp., including the brown recluse).” Below are a few of the most common dangerous spiders that can bite dogs, and why they are so harmful.
Black Widow Spiders
The black widow spider is one of the most recognizable and dangerous spiders for both humans and dogs. According to National Geographic, “This spider’s bite is much feared because its venom is reported to be 15 times stronger than a rattlesnake’s.” They are found in many parts of the United States, but they are most commonly located in the southern and western regions. They typically live in dark, sheltered areas, like wood piles, garages, sheds, and under outdoor furniture.
Female black widows are recognized by their shiny black bodies with a distinctive red hourglass marking. Immature female black widows lack this coloration, being red, brown, or beige, but they can also produce envenomation.
According to the American Kennel Club, “The jaws of the male spiders are too small to puncture a dog’s skin, but females are bigger and can easily bite a dog. Their bites leave two tiny puncture marks and are extremely painful. The pain starts at the bite site and spreads throughout the body. Signs can occur as soon as 30 minutes following the bite, and worsen over the next 8 hours.”
Black widow spiders are known for their potent neurotoxic venom, which affects the nervous system. The venom causes a release of neurotransmitters, leading to muscle contractions and potentially serious symptoms in dogs. Common symptoms include:
- Muscle tremors or cramping
- Difficulty breathing
- Paralysis in severe cases
- Weakness and lethargy
Note: This spider has other widow relatives. For example, the red widow spider may be less common but it’s equally venomous. Their bite injects neurotoxin venom, which disrupts nerve function and can lead to serious complications if left untreated. If you suspect your dog has been bitten by a widow spider, seek veterinary care immediately.
Brown Recluse Spiders
The brown recluse spider is another highly venomous spider that poses a threat to dogs. It’s particularly due to the spider’s necrotic venom. Brown recluses are primarily found in the central and southern United States, however, they can also be encountered in surrounding areas. They prefer dark, undisturbed areas such as basements, closets, wood piles, and sheds. Brown recluse spiders are tan to dark brown with a distinct violin-shaped marking on their back. So, they’re relatively easy to identify.
Their venom causes localized tissue damage, often resulting in painful, slow-healing wounds, and can lead to more severe systemic symptoms if left untreated. Due to the delayed effects of their bite, it’s important to monitor any potential spider bite closely and seek veterinary care immediately. Common symptoms include:
- Tissue death (necrosis) around the bite
- Lethargy and fever
- Vomiting or nausea
- Severe itching and pain around the bite
Note: Like widow spiders, the brown recluse isn’t the only recluse to watch for. Like its relative the brown recluse, the Chilean recluse spider is extremely venomous. Its venom is more potent, leading to more severe tissue damage and, in rare cases, systemic illness.
What to Do If a Spider Bites Your Dog
If you suspect your dog has been bitten by a spider, here are the steps to take:
- Identify the Spider: This isn’t always possible. But, if you can safely do so, try to identify or capture the spider that bit your dog. This will help the vet determine the appropriate treatment.
- Clean the Bite Area: With your vet’s guidance, gently wash the bite area to remove any venom or bacteria.
- Monitor Your Dog: Keep a close eye on your dog’s behavior and physical condition. Note any swelling, changes in temperament, or signs of distress.
- Seek Veterinary Care: If you suspect the bite came from a black widow, brown recluse, or any other venomous spider, contact your vet immediately. Even if the spider wasn’t venomous, it’s a good idea to have your dog checked out to prevent infections.
- Follow Treatment Protocol: Your vet may administer antivenom, pain relief medication, or antibiotics depending on the type of spider and the severity of the bite.
Treatment for Spider Bites in Dogs
Treatment for spider bites can vary depending on the severity of the bite and whether venom was involved. Here are some typical treatments your vet might use:
- Antivenom: For dogs bitten by black widow spiders, antivenom may be administered to neutralize the venom. This medication is given intravenously (IV). (Brown recluse spider bites are treated with supportive care, as there is no available antivenin in the United States.)
- Pain management: Pain relief medication is often prescribed to keep your dog comfortable, especially if the bite is causing significant discomfort.
- Wound care: If the bite has caused tissue damage or ulceration (common with brown recluse bites), your vet may provide wound care to help the area heal and prevent infection.
- Intravenous fluids: In severe cases where systemic symptoms like weakness, fever, or muscle tremors are present, your dog may require IV fluids to stay hydrated and stabilize their condition.
- Surgery: In very rare and extreme cases, such as severe necrosis from a brown recluse bite, surgery may be required to remove the dead tissue.
Preventing Spider Bites in Dogs
While it’s impossible to completely eliminate the risk of spider bites, there are steps you can take to reduce the chances of your dog being bitten:
- Regularly Clean Your Home: Keep your home free of spider webs and reduce clutter in areas like basements, garages, and closets where spiders may hide.
- Seal Entry Points: Make sure doors, windows, and vents are properly sealed to prevent spiders from entering your home.
- Inspect Outdoor Spaces: Keep your yard free of wood piles, tall grass, leaf piles, or other debris where spiders may be hiding.
- Keep Dogs Away from Spider Habitats: If you’re in an area known for venomous spiders, prevent your dog from exploring crawl spaces, sheds, or other places where spiders may be lurking.
