Black Widow Spider Bite In Dogs: (Signs Of Bite Symptoms)

House spiders are a pretty common problem in the US, especially for those with pets. Spiders inhabit our homes, and while they’re usually hiding in the dark, less frequently visited corners of the house, they can find their way to your pet.

Most house spiders do not pose a significant threat to your dogs, but some species can be hazardous.

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For example, the black widow spider is one of the most common house spiders with a dangerous bite. This creepy critter can seriously harm you and your canine family members.

Today, we will tell you everything you need to know about black widow spider bites in dogs and what you can do about it.

Before we dig in, here is a quick rundown of what you will learn in this article:

Black Widow Spider bite in Dogs Key Takeaways

  • When it comes to house spiders, there are only two main species you need to watch out for. One of them is the black widow spider.
  • Black widow spider bites in dogs can have life-threatening bites that can cause real damage to your pup.
  • Black widow spiders have venomous bites, which you can easily identify as they have distinguishing side effects.
  • A black widow spider bite can cause whining, drunk walking, irregular breathing, rapid changes in heartbeat, and other symptoms.
  • You can use different remedies to soothe the bite and the skin around it, but you should consult a vet if your dog gets bit by a black widow spider.

Black Widow Spider Bites in Dogs

Black widow spiders are found in most households in the country but are most common in North America. These spiders are shiny and black with orange or red marks on their body. Most male species are dark brown in color and bigger in size compared to female black widow spiders.

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Black widow spiders are poisonous, and a single bite can cause many problems for cats and dogs. They have a potent venom (a-latrotoxin) which can cause neurotoxicity.

So, dogs who get bit by a black widow spider often exhibit signs of severe cramping, muscle pain, tremors, drunk walking, diarrhea, vomiting, paralysis, and more.

Black widow spider bites are treatable with IV fluids, antivenom, anti-seizure medications, painkillers, and other medications. Most dogs recover, but if not treated on time, small and young dogs can even die from a Black widow spider bite. So, a black widow spider biting a small dog is fatal.

Black Widow Spider Bite Poisoning in Dogs

Black widow spider bite poisoning in dogs is toxic. The venom of black widow spiders causes poisoning when they bite their targets. Insects, pets, and humans are the typical targets of a black widow spider.

The venom includes a neurotoxin that impacts the nerve endings. So, once the poison is absorbed in the bloodstream, it produces harmful side effects like severe pain, involuntary muscle spasms, blurred vision, headaches, weakness, nausea, and behavioral problems.

Black widow poisoning can also lead to damaged tissues. And, if not treated in time, it may even prove to be fatal to your dog.

Besides black widow poisoning, you should also watch out for brown recluses. This species of spider is one of the most poisonous and dangerous ones out there. These spiders are similar to black widows but smaller in size.

Brown recluse black widow spider bite on dogs is also painful and causes immediate itching and irritation. So, a dog bitten by a brown recluse or black widow will often be licking or biting the affected area.

How Dangerous is Black Widow Spider Bite in Dogs?

Black widow spider bites can be very dangerous to dogs. They cause severe health problems and can also be life-threatening for your dog.

Can dogs die from a black widow bite?

Thankfully most spiders are nothing more than a nuisance. But black widow spider bite can kill dogs. Black widow spider venom is a nerve toxin, so even a bite can be toxic enough to kill a small dog.

How long does it take for a black widow bite to kill a dog?

Dogs bitten by black widow spiders show signs of venom poisoning 4-5 hours after getting bitten.

With the proper treatment, most dogs survive a black widow spider bite, but if not given immediate treatment, the dog can pass away within 48 hours.

Black Widow Spider Bite Symptoms in Dogs

Now we will tell you about the symptoms associated with black widow spider bites in dogs.

What are the signs of dog black widow bite symptoms?

Here are the most common signs and symptoms dogs exhibit after a black widow spider bite:

  • Muscle cramps and severe pain
  • Drunk walking and dizziness (ataxia)
  • Tremors, seizures, and paralysis
  • Rapid changes in blood pressure and heartbeat
  • Nausea, vomiting, diarrhea, and upset stomach
  • Abdominal rigidity 
  • Excessive whining, howling and crying out
  • Breathing problems and respiratory collapse
  • Excessive drooling and restlessness
  • Death (in antivenom is not given on time)

How long after a black widow bite does a dog show symptoms?

If a black widow bites your dog, your dog will start showing some of the symptoms mentioned above within 4 to 8 hours.

If the bite goes unnoticed and untreated, your dog will start exhibiting more severe symptoms after 12 hours.

How long do black widow spider bite symptoms last?

The symptoms will last and continue to worsen until an antivenom is given to the infected dog. Once the dog gets antivenom, followed by treatment for side effects, it will start to improve. 

What happens if my dog gets bitten by a black widow?

If your dog gets bitten by a black widow spider, a number of things can happen. First of all, there will be redness and swelling around the bite mark. There will also be hives and swelling on other body parts, like the face.

Then your dog will start showing signs of allergic reaction to black widow spider venom. These include pain, vomiting, inflammation, breathing problems, and paralysis.

Identifying Black Widow Spider Bite in Dogs

It is not easy to identify a spider bite, especially in dogs. You can’t see the skin directly as it hides under the coat. However, knowing the signs and symptoms can help you tell whether your dog got bit by a spider or not.

So, if you notice any of the following in your dog, then it is highly likely that they got bit by a venomous spider, like a black widow spider:

  • Itchiness and soreness around the bite
  • A part of the skin has turned dark and patchy
  • Your dog is suffering from chills, fever, nausea, pain, and rash
  • The darkened skin turns into blisters or non-healing wound

How do you know if your dog got bitten by a black widow?

As we stated earlier, it is not easy to spot spider bites on dogs. Usually, you don’t even notice any symptoms for hours after your dog is bitten. The only way to know for sure is by taking your pet to the vet after observing any of the above-mentioned symptoms.

Getting your pet thoroughly examined by a professional animal care expert will tell you whether or not your pup got bitten by a spider.

What does a black widow spider bite look like on a dog?

A black widow spider bite on a dog often results in red and swollen skin. The skin tissue around the bitten area dies, causing a dark and dry patch.

The color of the lesion will continue to darken as the venom continues to spread and progress in the rest of the body. The bite mark may also develop blisters or a bullseye appearance.

What does a spider bite look like on a dog’s paw?

A black widow spider bite will cause a red bump on your dog’s paw. It looks similar to mosquito bites and causes a lot of irritation. So, you may catch your dog licking, scratching, and biting the bite mark.

Treatment of Black Widow Spider Bite on Dogs

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Treating a black widow spider bite on time is extremely crucial to your dog’s life. Your dog will suffer serious consequences if you are even a bit negligent in seeking proper treatment soon.

Here is what you need to know about treating black widow spider bites in dogs:

What do you do if your dog gets bitten by a spider?

The first and most important thing to do is call your vet. Explain your dog’s condition to the vet so he can tell you whether you need to take it to the nearest emergency clinic or treat it at home.

In most cases, the dog should be taken to the vet clinic for antivenom and additional medications to ease the symptoms and side effects.

When should I take my dog to the vet for a spider bite?

If your dog gets bitten by a black widow spider, immediately take him to the vet. Do not wait for the symptoms to worsen, as the venom of the black widow spider can even kill your dog.

How do you treat a black widow bite on a dog?

Your vet will create a proper treatment plan for your dog. A dog suffering from a black widow spider bite is mostly admitted and given antivenom and other supportive treatment.

Here are some of the main things involved in black widow spider bite treatment:

  • The doctor will give IV fluids for hydration and additional medications for pain management.
  • Your dog may also be given medications as muscle relaxants help with spasms and seizures.
  • The vet will monitor your dog and keep it under observation to prevent issues like a reaction to meditation, respiratory distress, irregular heartbeat, etc.
  • Black widow antivenin called Latrodectus is also used, which also requires constant monitoring.
  • It takes 48 to 72 hours for most dogs to recover, but some may take longer. Your dog will face fatigue, weakness, and insomnia after the treatment.

What can I give my dog for a spider bite?

Most spider bites are not poisonous and may not cause any side effects. However, the same cannot be said for black widow spider bites.

If you cannot take your dog to the vet right away, get a black widow antivenin and give it to your dog. It will start working within 30 minutes.

How do you treat a spider bite on a dog at home?

Most spider bites don’t need much attention and care as they are not harmful. They may cause slight irritation on the skin. Nonetheless, if your dog is allergic to spider bites, there are some simple home remedies you can try.

If a black widow spider bites your dog, there is not much you can do for envenomation at home. But some of these home remedies may ease the symptoms of black widow spider bites. You can also use the below-mentioned tips and tricks as a home remedy for brown recluse bites on dogs.

Home Remedies for Spider Bites on Dogs:

Wound Care

The skin becomes quite sensitive after a venomous spider bite. Make sure you keep it clean and apply proper wound care to prevent bacterial infections. Clip the hair around the wound and use antimicrobial and antibacterial sprays or ointments.


Ice reduces swelling and soothes irritation and itching. It will also help with redness and pain. Just ensure not to apply the ice pack for too long, as it may lead to frostbite.

Pain Meds

Pain Meds

Spider bites are painful, especially venomous spider bites. Consult with your vet and give your dog an anti-inflammatory medication like aspirin to help with the pain. Such medicines will provide temporary relief. Do not give any strong painkillers like ibuprofen or acetaminophen without the vet’s permission.

Baking Soda

Make a paste with baking soda and water and apply it on the bite mark. Do not run it on the wound. Just apply the paste and let it dry down.


Your dog may show signs and symptoms of an allergic reaction to the bite even if the spider is not venomous. Giving an antihistamine will help quell the symptoms like redness, itching, swelling, etc.

Canine-Safe Corticosteroid

Corticosteroids are topical treatments that will give relief to your dog’s skin. Apply it to the bite mark, and within 20 minutes, your dog will have comfort from itching and irritation.

Potato poultice

Potato poultice

Slice up a potato and put the pieces in a clean cloth. Apply the poultice on the bite mark to reduce irritation and inflammation on the skin.

Turmeric Powder

Turmeric powder is a natural antibiotic. Make a mixture of turmeric powder with olive oil and rub it on the spider bite. This will heal the sound and give your dog relief from inflammation.



Salt is an excellent remedy for venomous spider bites. Wash the bite mark with salt water or sprinkle some table salt on the affected area. Salt will soak up some of the venom and slow it down from quickly spreading to the rest of the body.

How to Prevent Black Widow Spider Bites in Dogs?

You can’t really keep track of the spider hiding in the dark corners of your home, but you can prevent spider bites on your dog.

Here are some simple ways to keep your dog safe from spiders and prevent black widow spider bites in dogs:

Bug Spray:

Bug Spray

Get a strong bug spray and spray it in every nook and cranny of your home. It will keep spiders and other pests away. here is a list of dog safe pesticides for our Smart Dog Owners.

Clean up:

Spiders usually reside in the hidden areas of the house where we usually don’t clean. So, ensure you have a deep cleanup of every area of your home at least once a month.

Topical repellents:

You can apply topical creams and bug-repellent lotions on your dogs to keep them safe from spiders and other nasty critters. Most of them contain pyrimethamine, but you can also find all-natural, chemical-free formulas on the market.

Are Black Widows Deadly To Dogs?

Yes, black widow spider bites can be deadly for dogs. They have a potent venom that can lead to a number of serious physical, cognitive, and behavioral disorders, leading to death.

Can a black widow bite hurt a dog?

Yes, black widow spider bite can hurt dogs in many ways. The bite causes skin irritation, inflammation, itching, and swelling. As the venom spreads through the bloodstream, your dog becomes weaker and will exhibit symptoms like fever, paralysis, tremors, vomiting, diarrhea, and more.

Can a dog survive a black widow bite?

Yes. Fortunately, dogs can survive black widow spider bites if given immediate medical attention and treatment. Take your dog to the get as soon as he shows any signs of spider bite poisoning.

Final Thoughts | Black Widow Spider Bite In Dogs

Keeping your dog’s safe from creepy crawly insects is a huge part of caring for a pet. You need to make sure you have proper preventative measures in place to prevent spider bites and other health hazards. However, there’s only so much we can do.

Watch out for any symptoms of venom poisoning and spider bites. If your dog gets bitten by a black widow spider, make sure you take your pup to the vet for immediate medical attention.

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Jackob Evans

Hi, I’m Jacob. I’ve been a professional blogger for over six years, and in that time, I’ve written countless blogs that have helped millions of people worldwide. A DVM by profession, I have treated and cured thousands of dogs, if not millions.

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