Can A Brown Recluse Kill a Dog

Can A Brown Recluse Kill a Dog?

Last Updated: August 18, 2023
correct answerThe Short Answer is:

You should be very careful with a brown recluse bite if you have a small dog, as there are no known incidents. A toy dog may become seriously infected if enough venom is injected into it. Anemia, blood clots, and kidney failure can result from this. The worst part of brown recluse venom is that there is no antidote.

In this article you will know the answer to the query “Can A Brown Recluse Kill a Dog?“.

People typically run away from a spider or attempt to kill it when they see one.

Can A Brown Recluse Kill a Dog

Unfortunately dogs have no fear of a tiny insect and being curious by nature they are at risk of getting bitten by a spider.

Even though brown recluse spiders are not all venomous they can cause serious injuries. 

Can a brown recluse kill a dog outright?

An attack by a brown recluse would not kill your dog directly at least not directly.

The bad news is that such bites can cause severe pain and can cause a deadly infection if left untreated.

The following information tells you everything you need to know about brown recluse spiders how to recognize the signs of venom poisoning and how to treat the wound.

What are brown recluse spiders?

In the central and southern parts of the United States the brown recluse also known as the fiddle spider is widespread. It is found in Kansas Oklahoma Texas Louisiana Arkansas Missouri Mississippi Alabama and parts of Georgia Tennessee Kentucky Ohio Indiana Illinois Iowa and Nebraska. You are unlikely to come across a brown recluse spider outside of this area but there are other spiders to watch out for.

The scientific name of this spider is Loxosceles reclusa and it belongs to the Loxosceles genus. 

How to spot a brown recluse

The violin-shaped markings on the back of all spiders in this group make them easy to identify which is why they are sometimes called violin spiders. Spiders have dark brown markings on their backs as adults. 

The brown recluses eyes are another distinctive feature. In some spiders there are six eyes arranged in three pairs while in others there are eight eyes arranged in two rows of four.

The recluse has uniformly colored legs without any patterns or spines and its body is less than 3/8 inches (1 cm) long. 

Its unlikely that the spider that bit your dog will stay around for long enough for you to identify it but if your pet develops a nasty wound you might want to check the house and call pest control.

Preferred hiding spots

Insects such as crickets or silverfish provide food for these nocturnal creatures. Their hiding spots are dark and sheltered during the day. They can be found in hollow trees or rock cracks as well as inside boxes shoes and trash cans. Most brown recluse spiders stay to themselves but during mating season when males venture outside to find females they become more reckless.

During her lifetime the female of the species needs to mate only once to produce fertilized eggs. If one gets inside your house you’ll have a serious problem. A brown recluse can produce 150 or more spiderlings per year.

Would a brown recluse spider attack a dog?

The brown recluse spider does not attack humans or animals without provocation. Dogs however can unintentionally provoke spiders by sticking their noses into places they should not. A dog that walks into or sits on a brown recluses web will usually get bitten.

How to identify a spider bite?

Brown recluse spider bites usually do not cause pain so do not expect your dog to yelp unless the spider attacks a very sensitive part of his body. However once the venom gets inside it will start working and the symptoms will appear in 2-8 hours. The dog will develop a red spot of skin around the site of the bite. In addition to being itchy this type of bite can lead to the dog scratching himself which can result in an infection that has nothing to do with the original bite. 

Brown recluse bites have the appearance of a bullseye with white centers. There may also be blisters and swelling at the site of the bite. 

In most cases brown recluse bites cause necrosis or cell death. In the affected area the dead cells begin to fall off leaving a wound that is black and gaping. The wound may take months to heal so you should check for signs of infection frequently.

Can a brown recluse bite kill a dog?

You should be very careful with a brown recluse bite if you have a small dog as there are no known incidents. A toy dog may become seriously infected if enough venom is injected into it. Anemia blood clots and kidney failure can result from this.

The worst part of brown recluse venom is that there is no antidote. However the vet might prescribe corticosteroids to reduce the chances of a systemic infection.

How to tell if your dog has been bitten by a brown recluse

Since you are unlikely to witness the spider biting your pet you will be very surprised when it starts feeling sick. The following symptoms can help you determine if you’re dealing with a dog bite rather than another health concern. 

  • An inability to put weight on one leg because of pain
  • You can not touch the affected area when the dog is showing signs of pain
  • Red itchy lesion with a bullseye appearance
  • Swelling or blistering
  • Local inflammation
  • Blackened skin around the bite site from necrotic tissue
  • Hole after the damaged tissue has fallen off
  • Scabs that take months to resolve

Even though spider bites can be uncomfortable you should really worry about a systemic infection. Such infections are more common in small dogs or pets with compromised immune systems. Look for symptoms like:

  • Fever 
  • Excessive thirst
  • Nausea and vomiting
  • Water retention (edema)

A systemic infection can lead to kidney failure shock and death if left untreated. 

How is brown recluse bite poisoning diagnosed?

If your dog exhibits any of the above symptoms and has an insect bite mark you should take him to the vet immediately. If you have seen the spider the veterinarian may want to know. By describing the spider a doctor can determine whether its a brown recluse or not.

When your dog is seriously ill the vet will run blood tests to look for signs of anemia or systemic infection.

How is brown recluse bite poisoning treated?

The bite mark should be disinfected as soon as possible if you notice it early on. You can give your dog a quick bath with soap and water to clean the wound. After applying hydrogen peroxide apply any antiseptic ointment you have around the house.

An ice pack can be applied to the swollen area around the bite to reduce inflammation.

Especially if you have a smallish sensitive dog you should consult your veterinarian right away. It is most effective to give the dog corticosteroids as soon as possible. The corticosteroids prevent the necrosis from spreading too much and they can also protect against systemic shock.

Apart from that the vet may prescribe fluids and electrolytes to help the dogs body fight off the infection. 

A blood transfusion will be necessary if your dog suffers severe poisoning resulting in blood clots and anemia.

An antidote isnot available but a vet might prescribe dapsone a drug used to treat leprosy in severe cases. It is possible that your dog may need to be monitored overnight.

Your veterinarian may prescribe antibiotics to prevent infection if your dog seems fine except for the wound.

The wound will need to be cleaned several times a day with antiseptic solution and a bandage may be required. In some cases this may be useful to keep the dog from scratching at the wound but not all dogs will tolerate one especially if the wound is in an easy-to-reach place. 

Oxygen therapy may be needed if the dog experiences breathing difficulties.

When the dog has explored a dark dusty corner or has rolled in the dirt a tetanus shot is recommended. 

What other spiders are dangerous to dogs?

Brown recluse spiders are only found in certain parts of the United States but other types of venomous spiders are found almost everywhere. Experts estimate that there are around 30 types of spiders that can severely harm or even kill dogs.

Black widow 

Black widow spiders are very dangerous both to humans and to dogs because their females devour their partners immediately after mating. The neurotoxin injected by a black widow can cause severe muscle pain and cramps nausea and mild paralysis of the diaphragm which makes breathing difficult. A very small dog could suffer fatal consequences from a bite from a black widow.

Brazilian wandering spider

Although the name suggests this spider is most often found in Brazil it can travel the world hidden inside banana cases. Brazilian wandering spider infestations have been reported in many parts of the world. The bite of this spider can cause an irregular heartbeat making it among the most dangerous spiders.

Brown widow

Although it originated in Africa this spider has made its way to faraway places such as the United States Australia and Europe. Fortunately the brown widow injects only a small amount of toxin when it bites. Its venom is twice as deadly as that of the black widow. 

Wolf spider

In North America there are around 125 species of wolf spiders while in Europe there are approximately 50 species. Generally wolf spider bites are not considered lethal but some people can be allergic to their venom. Dogs are unlikely to be affected by allergies caused by wolf spider bites. 

The bite from these spiders however can be extremely painful due to their long fangs.

Yellow sac spider

The yellow sac spider is common throughout the Americas. Their toxins can destroy cells but a bite rarely results in necrosis of the tissue. 


A bite from a brown recluse spider can be lethal to dogs but in most cases it would not be fatal. Dogs however will suffer greatly as a necrotic bite can occur. In a few days the bite site will turn black and as dead cells start to fall off a large hole will be left behind. In such cases healing can take months.

When you see symptoms indicating a spider bite on your dog you must immediately take it to the vet if your dog is small or has a weak immune system. Such bites can cause anemia organ failure systemic infection and even death if left untreated. 

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Amanda Dogs Trainer

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With over a decade of experience, Amanda is a distinguished dog trainer. Her expertise in canine behavior has transformed countless lives, fostering harmonious human-canine connections. Through compassionate and personalized approaches, she empowers owners to understand and connect with their furry companions, creating a legacy of joyful tails and transformed lives.

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Osvaldo Maciel, a stalwart in the field with 14 years of experience, is a revered dog trainer. His journey is defined by a profound understanding of canine behavior, shaping unbreakable human-canine bonds. Osvaldo guides owners to connect with their beloved pets, leaving an indelible mark of happiness and transformation. His legacy shines through the countless lives he has touched.

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