Spider Bites on Dogs: A Complete Guide for Owners

Spider bites on dogs are usually no big deal. Most heal on their own without you even noticing. But knowing how to spot a spider bite on dog and when to worry is key. This guide covers everything from prevention and symptoms of spider bites on dogs to first-aid tips, so you can keep your pup safe, whether at the park or in your backyard.

Sometimes, though, a spider bite does require treatment or even immediate medical attention. Here’s what you need to know to keep your pup safe on all your adventures:

• Do venomous spiders live in the United States?
• What dangerous spiders to watch for in different parts of the country
• Spider bite prevention in dogs
• How to identify a spider bite on your dog
• What to do if a spider bites your dog
• Additional canine first aid resources

Are There Venomous Spiders in the US?Yes, the United States has venomous (or poisonous) spiders

The United States is home to a few species of venomous spiders.

Key Takeaways

• Most spider bites aren't serious: Venomous spiders exist in the US, but most bites cause only mild reactions. Be observant and prepared to act quickly if needed.
• Familiarize yourself with local spider species: Understanding the types of spiders in your area, especially venomous ones, helps you protect your dog during outdoor activities.
• Contact your vet if you're worried: If a spider bites your dog, or if you notice any unusual symptoms after a possible encounter, consult your veterinarian. Quick action is always the best approach.

Venomous vs. Poisonous Spiders: What's the Difference?

To get technical, “venomous” is more accurate than “poisonous” here. Venomous means the spider injects venom into potential threats through fangs or stingers. Poisonous refers to animals that are harmful when ingested or touched.

Why Differentiating Between Venomous and Poisonous is Important for Dog Owners

Understanding the difference between venomous and poisonous isn’t just a fun fact—it’s crucial for dog owners. While most spider bites are harmless and heal on their own, certain species pose serious health risks to our pets. The black widow and brown recluse spiders, for example, are two of the most dangerous spiders in North America. A bite from a black widow can cause immediate pain, muscle cramping, and other severe symptoms. A brown recluse bite, on the other hand, may initially seem minor but can lead to significant tissue damage over time (VCA Animal Hospitals).

Most spiders are venomous, but their fangs are often too small to break a dog's skin. This means the bites aren’t medically significant (VCA Animal Hospitals). Still, being able to identify the few venomous species that can cause harm is essential for ensuring your dog’s safety. If you think your dog has been bitten by a venomous spider, seek immediate veterinary care (Rock Hill Emergency Vet).

Are Most Venomous Spider Bites Dangerous?

Most spider bites in the United States, even from venomous species, result in only mild symptoms. Phew!

Don’t get too complacent, though. If you suspect your dog has been bitten by a venomous spider—or they experience severe symptoms out of the blue—seek medical care right away. Practice good spider bite prevention techniques to reduce the risk of bites in the first place. (More about prevention and treatment in the next sections.)

Why Most Spider Bites on Dogs Are Harmless

Most spider bites on dogs aren't a cause for alarm. Most spider bites—to both dogs and humans—aren’t cause for serious concern. They typically cause minor irritation or redness, similar to a mosquito bite. These small bumps often heal on their own without any special attention. Many pet owners may not even notice them.

While the United States has several species of venomous spiders, most spider bites in the US, even from venomous species, result in only mild symptoms (VCA Animal Hospitals). Symptoms can include swelling, redness, and localized pain, but these reactions are generally not severe. Most spider bites heal without long-term problems.

However, it’s important to stay aware. If you think your dog has been bitten by a venomous spider, or if they show severe symptoms, seek veterinary care right away. Good spider bite prevention techniques can also help reduce the risk of bites. Bringing your dog to a safe, enclosed space like a Sniffspot can help minimize their exposure to spiders and other biting insects.

Venomous Spiders in the US: Where Do They Live?What venomous spiders live in the US? What areas of the country have the highest spider bite risk?

Spiders typically prefer quiet, undisturbed areas. They’re usually not aggressive toward humans or our dogs. Most spider bites are the result of accidental contact or disturbance. That means the presence of venomous spiders in a particular region doesn’t necessarily suggest encounters with them are common.

In fact, the exact incidence of the below spider bites in dogs is unknown. That’s actually a good sign: It means veterinarians don’t see enough serious or lethal cases to collect data!

There’s still a chance your pup has an arachnid encounter, though. Here are some species of spiders to watch for on your adventures.

Black Widow Spider bites — emergency — found in all states

Black widows are perhaps the most well-known venomous spiders in the United States. Found throughout the country, they’re most common in warmer southern climates.

Black widows are known for shiny black bodies with a distinctive red hourglass shape on their abdomen.

Black Widow Spider Bite Symptoms in Dogs

Black widow spider bites can cause a range of symptoms in dogs, from mild irritation to severe illness. A bite can cause immediate pain at the site. More concerning symptoms, according to VCA Animal Hospitals, can follow, including muscle pain and cramping, vomiting, diarrhea, tremors, and agitation. You might also notice muscle rigidity, rapid heart and respiratory rates, and abdominal pain.

Because some of these symptoms are common to other illnesses, diagnosing a black widow spider bite definitively can be tricky. If your dog displays any combination of these symptoms, especially after spending time outdoors in a potential spider habitat, seek veterinary care right away.

What to Do if Your Dog is Bitten by a Black Widow

If you think a black widow spider bit your dog, don’t panic, but do act quickly. Seek veterinary care immediately. The sooner your dog receives treatment, the better the outcome.

Treatment for venomous bites may include antivenom, IV fluids, pain medication, and antibiotics. While waiting for veterinary care, keep your dog calm and comfortable. If possible, and if you can do so safely, try to collect the spider (even if it's dead) for identification. This can help the vet determine the best course of treatment.

"Dry Bites" and Their Significance

Not all black widow bites result in venom injection. VCA Animal Hospitals notes that about 15% of bites are "dry bites," meaning no venom is injected. A dry bite can still be painful because of the physical injury, but it won't cause the more serious symptoms associated with venom.

Even with the possibility of a dry bite, it's crucial to treat every suspected black widow spider bite seriously. It's impossible to tell a dry bite from a venomous one without medical evaluation, so always err on the side of caution and contact your veterinarian.

Brown Recluse Spider bites — emergency — Midwest and South

Brown recluse spiders are found primarily in the Midwest and southern United States. Their venom can cause necrotic skin lesions in some cases—but severe brown recluse bites are thankfully rare, because these arachnids need counter pressure in order to break the skin. Brown recluse bites are most often found on dogs’ legs.

This species is brown with a distinctive violin-shaped marking on their back.

Brown Recluse Spider Bite Symptoms in Dogs

Brown recluse spider bites initially cause little to no pain. You might not even realize your dog’s been bitten at first. Within a few hours, a blister will develop. This blister can turn into a “bulls-eye” lesion—a red, inflamed area surrounding a pale center where the tissue begins to die (necrosis). If the bite is on a leg, your dog might limp or avoid putting weight on it. Fever and lethargy can follow. In severe cases, more serious symptoms like bleeding, seizures, or respiratory problems can occur.

What to Do if Your Dog is Bitten by a Brown Recluse

If you think a brown recluse has bitten your dog, contact your veterinarian immediately. Like with black widow bites, quick action is key. Your vet might recommend home treatment for mild cases, or they may advise an emergency visit. Veterinary treatment may include pain medication, antibiotics to prevent secondary infection, and supportive care to manage any systemic effects of the venom.

Chilean Recluse Spider bites — emergency — some Southern states

Chilean recluse spiders are most commonly found in South America, but they can make their way to the southern United States. They’re more venomous than their brown recluse relatives. While bites in the US are rare, they need to be taken seriously right away.

Red Widow Spider bites — possible emergency — found in Florida

Red widow spiders are primarily found in the southeastern United States, particularly in Florida. They have a limited range compared to other widow spider species—so serious bites are less common. They can still cause severe symptoms in some cases, though!

Red widow spiders are known for their striking red or reddish-brown coloration. Like other widow spiders, they have a distinctive hourglass-shaped marking on the underside of their abdomen.

Brown Widow Spider bites — possible emergency — some Southern states

Brown widow spiders are commonly found in the southern and southwestern parts of the country. This species’ range includes states like Florida, Texas, California, Arizona, and parts of the Gulf Coast. Their venom is less potent than the black widow—but even these little arachnids can cause serious effects, particularly in small dogs.

Brown widow spiders are typically light to medium brown in color and have an hourglass-shaped marking on the underside of their abdomen. This marking is usually orange, yellow, or even white. They are smaller than black widow spiders, with a body length of about 1/4 to 1/2 inch.

Hobo Spider bites — usually not emergency — West

Hobo spiders are found in the Pacific Northwest and parts of the West. While there have been concerns about their venom, they are not considered highly dangerous. Their bites usually result in mild symptoms.

How Can I Prevent Spider Bites on My Dog?How can you prevent your dog from being bitten by a spider?

The best treatment is prevention. Here are some steps you can take to help protect your dog from spider bites!

Perform regular home cleaning and maintenance

Keep your home, especially areas where your dog spends a lot of time, tidy and clutter-free. Regular cleaning can help eliminate hiding spots for spiders.

Inspect outdoor play areas

Before allowing your dog to play in outdoor areas, inspect the environment for spider webs, nests, or hiding spots. Remove any spider webs or nests you find.

Creating Safe Play Spaces on Sniffspot

If you're a Sniffspot host, maintaining a spider-free environment is key to ensuring a safe and enjoyable experience for all visiting dogs. Regularly inspect your property for webs and nests, especially in quieter corners and woodpiles. Keep the grass trimmed and clear away any debris where spiders might like to hide. By taking these simple steps, you can help protect visiting pups from unwanted spider encounters and maintain a welcoming space for everyone.

For guests booking through Sniffspot, remember that hosts prioritize safety and cleanliness. If you happen to notice any potential hazards, like spider webs, during your visit, don't hesitate to let the host know. Open communication helps ensure a positive experience for all.

Whether you're a host or a guest, taking proactive steps to prevent spider bites contributes to a safer and more enjoyable experience for everyone in the Sniffspot community. Looking for the perfect spot for your dog to run and play? Find a dog park near you!

Store firewood and debris away from living spaces

Keep firewood, garden debris, and other clutter away from areas where your dog spends time. These can be attractive hiding spots for spiders.

Check your dog’s bedding

Regularly inspect your dog’s bedding, crate, and sleeping areas for signs of spiders or spider webs. Shake out and clean bedding to remove any potential hiding spiders.

Be mindful of spiders’ favorite environments

When walking your dog in wooded or natural areas, be cautious around logs, rocks, and other potential spider habitats. Keep your dog on a leash if you’re uncertain to prevent them from sticking their nose into spider hiding spots.

Educate yourself on local spiders

Learn about the types of spiders in your area and their preferred habitats. This knowledge can help you identify potential risks and take appropriate precautions!

Supervise your dog

Keep an eye on your dog while they are exploring new environments, especially in unfamiliar outdoor settings. This way you can intervene if your dog encounters a spider.

Supervised Play at Sniffspot Locations

Sniffspot is all about providing safe, enriching experiences for dogs. When you visit one of our awesome locations, remember that supervision is key to preventing mishaps, including unwanted encounters with spiders. Keeping a close watch on your dog lets you step in if they start sniffing around areas where spiders might be hiding, like woodpiles or dense vegetation. Most spider bites are harmless, as MetLife Pet Insurance explains, but it’s always best to be cautious. Plus, supervised play just makes for a more fun and connected outing for both of you!

Sniffspot hosts also take steps to create safe environments for visiting dogs. Many hosts regularly clean their spaces, which helps eliminate those inviting spider hiding spots. Before your visit, you can always check with the host about their cleaning routines and any potential hazards. It’s a great way to get peace of mind and ensure a positive experience at your chosen Sniffspot. And remember, if you do happen to find a spider web or two, let the host know so they can address it.

Spider proof your home

Install screens on windows and doors to keep spiders and other insects out of your home. Seal cracks and gaps in walls and doors to prevent spiders from entering.

Did My Dog Get Bitten by a Spider?How do you know if your dog was bitten by a spider?

Identifying a spider bite on your dog can be challenging. Symptoms vary depending on the type of spider, your individual dog’s sensitivity (often based largely on body size), and the location of the bite.

Look out for these general signs to help you decide what to do next for treatment.

Spider bite symptoms in dogs

If you notice any of the following symptoms, consider the possibility of a spider bite and consult your veterinarian. Pay attention to your dog’s typical body language so you’re able to quickly identify signs of discomfort.

• Localized swelling: Spider bites often lead to localized swelling around the area of the bite. Swelling usually appears shortly after the bite occurs.
• Redness and skin irritation: The affected area may become red, inflamed, and irritated. It may also be warm to the touch. These symptoms of spider bites can appear like a range of other allergic reactions.
• Pain or discomfort: Your dog may show signs of muscle pain, joint pain, or other discomfort. They may lick, scratch, or chew at the area of the bite. Whining and vocalization can also be a sign of pain.
• Visible bite marks: You may be able to see two small puncture marks at the site of the bite. These marks often aren’t visible, though, especially if the spider bite was from a small species.
• Lethargy: Spider bites can cause lethargy or weakness in your dog. Your pup may appear tired, listless, or reluctant to move.
• Loss of appetite: A spider bite can lead to a loss of appetite in your dog.
• Vomiting or diarrhea: Some dogs experience gastrointestinal symptoms such as vomiting or diarrhea as a result of a spider bite.
• Difficulty breathing: In rare and severe cases, spider venom can cause difficulty breathing or other respiratory distress. This is more likely with certain venomous spiders like the black widow.
• Seizures or tremors: Extremely rare—in cases of severe envenomation (like from a black widow bite), your dog may experience seizures or tremors.

Diagnosing Spider Bites in Dogs

Diagnosing a spider bite on your dog can be tricky. It's often difficult to see the actual bite marks, especially with a thick coat. Plus, the symptoms of a spider bite can mimic other health issues, like allergic reactions or infections.

Start by checking your dog thoroughly. Look for any areas of swelling, redness, or irritation. Pay close attention to any spots your dog seems to be licking or chewing excessively. If you find a suspicious area, see if you can locate two tiny puncture marks—a telltale sign of a spider bite (though not always visible). Reactions vary depending on the spider, your dog's size and sensitivity, and the bite location.

Even if you're unsure, it's always best to err on the side of caution. If your dog exhibits any signs of discomfort or illness after a potential spider encounter, contact your veterinarian. They can properly diagnose the issue and recommend the best course of action. If you think your dog might have been bitten by a venomous spider like a black widow, seek immediate veterinary care. Early intervention is key.

My Dog Got Bitten by a Spider: What Now?What should you do if your dog was bitten by a spider?

If you’re able to capture the spider that bites your dog, keep it in a tight jar or other secure container and show it directly to your vet. This will help determine what treatment your pup needs.

If your dog was bitten by a non-venomous spider:

If you know your dog’s bite wasn’t venomous—or their symptoms are very mild—keep a close eye on their condition while trying to alleviate their discomfort. You can treat itching or mild swelling with a cool compress (like a soft ice pack wrapped in a towel) or pet-friendly pain reliever cream.

First Aid for Non-Venomous Spider Bites on Dogs

Most spider bites on dogs are harmless, causing minor irritation like a mosquito bite. If your dog is bitten by a non-venomous spider, you can usually treat it at home with simple first aid. Start by gently cleaning the bite area with mild soap and water. Then, you can apply a paste of baking soda and water to help soothe the skin and reduce itching. A cool compress can also help reduce any swelling. You can make a compress by wrapping a soft ice pack in a towel and applying it to the bite for short periods.

It’s important to prevent your dog from licking or scratching the bite, as this can introduce bacteria and lead to infection. If you’re concerned about your dog irritating the bite, you can use an Elizabethan collar (also known as a “cone of shame”) to block access to the area. Keep a close eye on the bite over the next few days. If you notice any signs of infection, such as increased redness, swelling, pus, or if your dog seems unwell, contact your veterinarian.

You can also treat itching or mild swelling with pet-friendly pain reliever cream. Just make sure to choose a cream that’s specifically formulated for dogs and follow the instructions on the packaging.

If your dog was bitten by a venomous spider:

Try to stay calm (we know, easier said than done) and keep your dog as still as possible as you get them to your nearest emergency vet. Unnecessary movement can spread venom through the bloodstream.

Once you arrive, follow the guidance of your veterinarian. They may recommend treatment for spider bites ranging from pain relief (often through oral or intravenous pain medication), muscle relaxers, antihistamines, or antivenom depending on the severity of the bite and the type of spider involved.

They’ll also monitor your dog’s vital signs like heart rate and watch for other clinical signs of long-term problems.

Specific Treatments for Venomous Spider Bites

Treatment for venomous spider bites depends on the spider and your dog’s reaction. For example, black widow bites are often treated with antivenom, pain medication, muscle relaxants, and fluids. Brown recluse bites, on the other hand, are usually treated with supportive care like wound cleaning, compresses, bandages, and sometimes antibiotics.

Your vet will determine the best course of action based on your dog’s specific situation. This is why it’s so important to seek veterinary care—even if you aren’t sure whether the bite was from a venomous spider.

Importance of Immediate Veterinary Care

If you suspect a spider bite, seek veterinary care right away. Even seemingly minor bites can sometimes cause unexpected complications. Quick action can significantly improve your dog's outcome, especially with venomous spider bites. Your vet can accurately diagnose the bite and provide appropriate treatment to manage pain, prevent infection, and address any other related issues.

If you can’t get to your regular vet, an emergency vet visit is a good option. Call your veterinarian for their recommendation on whether to seek emergency care or treat the bite at home.

Safely Capturing or Photographing the Spider

If possible, try to safely capture the spider for identification—but always prioritize your and your pet’s safety. Don’t put yourself at risk of getting bitten! A clear photo can also be helpful for identification.

If you’re able to capture the spider, place it in a secure container and show it to your vet. This can help them determine the best treatment plan for your dog.

If you aren’t sure what kind of spider (or insect) bit your dog:

It’s always better to be safe than sorry. If you live in an area with venomous spiders (so really anywhere in the United States—but especially southern states) and suspect your dog may have been bitten, consult your veterinarian immediately. They can provide guidance on what to do next!

More First Aid Resources for Your Dog

• Bee stings in dogs
• Ticks on dogs
• Preventing and treating heat stroke
• How to put together a dog first aid kit

Recovery Time for Spider Bites in Dogs

Most spider bites on dogs are harmless, causing minor irritation similar to a mosquito bite. These typically heal within two to three weeks. Even bites from venomous spiders often resolve with minimal intervention, especially if your dog is generally healthy and you practice good preventative care for things like fleas and ticks.

Venomous bites can take longer to heal depending on the severity. With proper treatment, full recovery is possible. Bites from brown recluse spiders, for example, may cause necrotic lesions that require several weeks or even months to fully heal. Supportive care like wound cleaning, compresses, and bandages are often part of the treatment plan, and sometimes antibiotics are necessary. Black widow bites are typically treated with antivenom, pain relievers, muscle relaxants, and IV fluids. Most spider bites, thankfully, heal without long-term problems.

If you’re ever concerned about a spider bite on your dog, it’s always best to consult your veterinarian. They can assess the bite, determine the best course of action, and provide the support your dog needs for a full recovery. Early intervention can make a big difference in minimizing discomfort and preventing potential complications.

Review of this Article

There is so much misinformation out there, and we want to make sure we only provide the highest quality information to our community. We have all of our articles reviewed by qualified, positive-only trainers or veterinarians.  

This is the professional that reviewed this article:

Amber Holly, BS, RVT, LVT

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Frequently Asked Questions

What are the most dangerous spiders for my dog in the US? The black widow and brown recluse are the two venomous spiders in the US that pose the greatest risk to dogs. Black widow bites can cause muscle pain, cramping, tremors, and other serious symptoms. Brown recluse bites can lead to tissue damage and necrotic lesions. While other venomous spiders exist in the US, their bites typically cause milder reactions.

What should I do if I think my dog has been bitten by a spider? If you suspect a spider bite, contact your veterinarian, especially if you live in an area where venomous spiders are common. If your dog shows severe symptoms like muscle cramps, difficulty breathing, or seizures, seek immediate emergency veterinary care. If possible, try to safely capture or photograph the spider for identification, but prioritize your and your dog's safety.

How can I prevent spider bites on my dog? Regularly clean your home and yard, paying attention to areas where spiders might hide, like woodpiles, sheds, and dense vegetation. Keep your dog on a leash in areas with potential spider habitats. When visiting dog parks or other outdoor spaces, supervise your dog closely and inspect the area for webs or spiders. At home, install screens on windows and doors, and seal any cracks or gaps where spiders could enter.

What are the signs of a spider bite on a dog? Spider bites can be tricky to identify, as they often resemble other skin irritations. Look for localized swelling, redness, and pain or discomfort at the bite site. Your dog might lick, scratch, or chew at the affected area. In more severe cases, symptoms can include lethargy, loss of appetite, vomiting, diarrhea, difficulty breathing, tremors, or seizures.

How are spider bites on dogs treated? Treatment depends on the type of spider and the severity of the reaction. For non-venomous bites, gentle cleaning of the area, a cool compress, and a pet-safe anti-itch cream can provide relief. Venomous bites may require pain medication, muscle relaxants, antivenom, or other supportive care. Your veterinarian will determine the best course of treatment based on your dog's specific needs.