Spider Bite on Dog: Symptoms, Treatment, and Prevention

Spider bites can be a common occurrence for dogs, especially those who spend a lot of time outside. While most spider bites are harmless, some can cause serious health issues for dogs. Dog owners must be aware of the signs and symptoms of a spider bite and seek veterinary care if necessary.

Symptoms of a spider bite on a dog can vary depending on the type of spider and the severity of the bite. While most times, our dogs are strapped in a quality dog harness, we can’t help but let them off leash sometimes. This is the time the pup can get a mild or nasty spider bite (although most spider bites happen at home).

Spider bite signs can range from mild redness and swelling to severe difficulty breathing and violent vomiting. It’s, therefore, crucial to understand different dog spider bite types and their signs. We’ve consulted expert sources like the Handy Guide to Bites and Stings for a comprehensive guide on dog spider bites. 

You don’t have to live in Australia to encounter one or two unforgettable spiders. Since canines are self-proclaimed Doras, you can be sure that they will run into the spiders and possibly get bit. 

Dog owners are equipped for many things, like getting ticks off their dogs and keeping flies away, but spider bites may be a new one. It’s also easy to confuse a spider bite for an ant or bee sting or even everyday zits and other skin infections. 

Prevention is key when it comes to spider bites on dogs. Keep your yard and home clean and clutter-free to reduce the chances of spiders making a home there. If you live in an area with a high risk of venomous spiders, consider using insecticides or hiring a professional pest control service.

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So, What Does A Spider Bite Look Like On A Dog?

Most spider bites cause a swollen, raised wound with a central puncture mark (or two puncture marks for widow spiders), resembling a bee or wasp sting. Common signs of a spider bite may include localized swelling and redness at the site of the bite, accompanied by pain or discomfort. In more severe cases, systemic symptoms such as fever, lethargy, vomiting, and muscle tremors may occur.

The biggest issue with insect bites is knowing which insect is responsible if you didn’t actually see your dog getting bit. So you’d find yourself blaming a spider, but it’s really a wasp or a bee that was a culprit (you can read our article on bee stings on dogs for more information).

In fact, a study found that several instances where a brown recluse spider was falsely accused of biting a dog were all caused by mites. 

However, let’s get into a few signs that could help you identify a spider bite if you don’t see your dog getting bit.

In the image below, the graph shows how a spider bite from a spider with nephrotic venom can progress over several weeks to help you know if your dog was bitten. The graph shows the human symptoms for necrotic arachnidism syndrome (a skin lesion from a spider), but it’s a good visual guide for how a bad spider bite on a dog will progress and what your dog may be feeling.

Physical Symptoms

Spider bites on dogs can manifest in various ways, depending on the type of spider that bites them. Some of the common physical symptoms of a spider bite on a dog include:

• Swelling and redness around the bite area;
• Pain and tenderness;
• Itching and irritation;
• Blistering and ulceration;
• Puncture marks;
• Weakness and lethargy;
• Fever;
• Vomiting and diarrhea; 
• Limping can sometimes occur; and
• Necrosis (tissue death) in severe cases.

It is important to note that not all spider bites on dogs result in visible physical symptoms. Sometimes, the bite may not leave any marks or only cause mild irritation.

Behavioral Changes

Besides physical symptoms, spider bites on dogs can also cause behavioral changes. Some of the common behavioral changes that dog owners may notice after a spider bite include:

• Restlessness and agitation;
• Lethargy and weakness;
• Loss of appetite;
• Vomiting and diarrhea; and
• Difficulty breathing in severe cases.

It is crucial to seek veterinary attention if a dog displays any of these symptoms after a spider bite. Prompt treatment can prevent complications and ensure a speedy recovery.

It’s important to note that since spider bites can be particularly rare in dogs, there is an over-emphasis in research on the most adverse reactions. So, researching studies on spider bites in dogs will probably make you feel like your dog is dying, even though they’ll probably have only a mild reaction. 

Common Types of Spider Bites in Dogs

Different kinds of spiders may have different effects, as follows

Black Widow Spider Bites On A Dog

Black Widow spiders are found in warm regions and are known for their black, shiny bodies with a red hourglass shape on their abdomen.

The venom of a Black Widow spider can cause severe symptoms in dogs, including muscle tremors, abdominal pain, and paralysis. Dogs may also experience difficulty breathing and vomiting. 

In fact, black widow bites can be so severe that a study on felines showed that 20 out of 22 cats died after exposure to its venom. 

Brown Recluse Spider Bites On A Dog

Brown Recluse spiders are found in the United States and are known for their brown color and violin-shaped marking on their back. 

The venom of a Brown Recluse spider can cause severe tissue damage in dogs, leading to necrosis and ulceration as show in the diagram we used above. Dogs may also experience fever, vomiting, and muscle pain. However, Rick Vetter has shown that necrosis can also result from mites and bed bugs.

Wolf Spider Bites On A Dog

Wolf spiders are found in many regions and are known for their hairy bodies and large size. They can cause swelling and pain at the site of the bite. Dogs may also experience fever, vomiting, and muscle pain.

Tarantula Spider Bites On Dogs

Tarantulas are found in many regions and are known for their large size and hairy bodies. The venom of a Tarantula spider is generally not harmful to dogs, with only mild symptoms such as swelling and pain at the site of the bite.

However, there was a pretty grim incidence where a whistling spider, a type of tarantula, caused seven dogs to die. This was after two owners were also bit but had nearly no reaction.

Brown Widow Spider Bite On Dog

Brown Widow spiders are found in the United States and are known for their brown color and hourglass shape on their abdomen. The venom of a Brown Widow spider can cause muscle pain, tremors, and abdominal pain in dogs. Dogs may also experience difficulty breathing and vomiting.

Red Widow Spider Bite On Dog

Red Widow spiders are found in the United States and are known for their red color and hourglass shape on their abdomen. 

The venom of a Red Widow spider can cause severe symptoms in dogs, including muscle tremors, abdominal pain, and paralysis. Dogs may also experience difficulty breathing and vomiting.

American Yellow Sac Spider Bite On Dog

American Yellow Sac spiders are found in many regions and are known for their yellow color and sac-like webbing. The American Yellow Sac spider can cause mild symptoms in dogs, such as swelling and pain at the bite site.

Immediate Actions to Take If Your Dog Was Bitten By A Spider

First Aid Steps

If a spider bites a dog, immediate action is necessary to prevent further harm. The following first aid steps can be taken:

• Keep the dog calm and still to prevent the venom from spreading quickly.
• Remove any tight collars or accessories around the dog’s neck.
• Clean the bite area with soap and water or a mild canine shampoo.
• Apply a cold compress to the bite area to reduce swelling.
• Elevate the limb to reduce swelling if the bite is on a limb.
• Make sure they don’t lick and bite the area.

Contacting the Vet

After taking the initial first aid steps, it is important to contact a veterinarian immediately. The vet can advise on further steps to take and provide necessary treatment. They will perform a blood test on your dog to determine which anti-venom to give them.

When contacting the vet, provide the following information:

• The dog’s breed, age, and weight.
• The type of spider that bit the dog, if known.
• The time that the bite occurred.
• Any symptoms the dog is experiencing, such as vomiting, difficulty breathing, or weakness.

It is important to note that some spider bites can be very dangerous and even fatal to dogs. Therefore, seeking veterinary care as soon as possible after a spider bite is crucial.

How To Treat Spider Bites On Dogs

Spider bites on dogs are common, especially during warmer months. While some spider bites may cause only mild irritation, others can be more severe and require immediate medical attention. This section will discuss how to treat spider bites on dogs.

Medical Treatments

If your dog has been bitten by a spider, it is important to seek medical attention as soon as possible. The veterinarian will assess the severity of the bite and determine the appropriate course of treatment. Some common medical treatments for spider bites on dogs include:

• Anti-venom
• Antihistamines: These are medications that can help reduce swelling and itching caused by spider bites.
• Steroids: Steroids can help reduce inflammation and swelling caused by spider bites.
• Painkillers: If your dog is in pain, the veterinarian may prescribe painkillers to help manage the pain.
• Antibiotics: If the spider bite becomes infected, the veterinarian may prescribe antibiotics to prevent further infection.

Home Remedies

While medical treatment is important, some home remedies can help alleviate symptoms of spider bites on dogs. It is important to note that home remedies should not replace medical treatment, but can be used in conjunction with it. Some common home remedies for spider bites on dogs include:

• Cold Compress: Applying a cold compress to the affected area can help reduce swelling and itching.
• Baking Soda: Mixing baking soda with water to create a paste and applying it to the affected area can help reduce swelling and itching.
• Aloe Vera: Applying aloe vera gel to the affected area can help reduce swelling and itching.
• Epsom Salt: Soaking the affected area in warm water with Epsom salt can help reduce swelling and itching.

Prevention of Spider Bites

Home Prevention

It is vital to keep your home clean and tidy to prevent spider bites. Spiders are attracted to clutter and dark, undisturbed areas. Regularly vacuuming and dusting your home can help to eliminate spider-hiding spots. Additionally, sealing cracks and gaps in windows, doors, and walls can prevent spiders from entering your home.

Essential step in home prevention is keeping your pet’s bedding clean and debris-free. Spiders may be attracted to bedding left outside or in dark, damp areas. Washing your pet’s bedding regularly can help to prevent spider infestations.

Outdoor Prevention

To prevent spider bites while outdoors, it is important to wear protective clothing such as long-sleeved shirts and pants. Additionally, insect repellent can help keep spiders and other insects away.

When spending time outside with your pet, it is important to keep them on a leash and supervise them at all times. Avoid letting your pet explore dark, undisturbed areas where spiders may be hiding.

It is also important to regularly inspect your outdoor living spaces and remove any spider webs or egg sacs. This can help to prevent spider infestations and reduce the risk of spider bites.

Understanding the Risks and Complications

Potential Health Risks

Spider bites can pose serious health risks to dogs. The severity of the reaction depends on the type of spider, the size of the dog, and the amount of venom injected. Some of the potential health risks associated with spider bites on dogs include:

• Pain and Swelling: The bite site may become swollen, red, and painful. The swelling can be severe and may spread to other parts of the body.
  
• Necrosis: Some spider bites can cause tissue death (necrosis) around the bite site. This can be particularly dangerous if the bite is on the face or neck, where the necrosis can affect the airway.
  
• Systemic Symptoms: In some cases, spider bites can cause systemic symptoms such as vomiting, diarrhea, fever, and muscle tremors. These symptoms can be life-threatening if left untreated.

Possible Long-Term Effects

In addition to the immediate health risks, spider bites can also have long-term effects on dogs. Some of these effects may include:

• Scarring: If the bite site becomes necrotic, it may leave a scar. This can be particularly problematic if the bite is on the face or neck.
  
• Behavioral Changes: Dogs that have been bitten by spiders may develop a fear of spiders or other insects. They may also become more aggressive or anxious.
  
• Allergic Reactions: Some dogs may develop an allergic reaction to spider venom. This can lead to anaphylaxis, a life-threatening condition that requires immediate medical attention. A study of a one-year-old male terrier showed that anaphylactic signs include excitement, vomiting, tremor, diarrhea, and hypersalivation.

Can a Spider Bite Kill a Dog?

Spider bites on dogs are relatively common, and most of the time, they are not life-threatening. However, in some very rare cases, spider bites can be fatal to dogs. Black widows, specifically, can affect the entire system and cause kidney failure.

The severity of a spider bite depends on several factors, including the spider’s size and species, the bite’s location, and the dog’s size and health status. Some spiders, such as the black widow and brown recluse, are venomous and can cause serious health problems in dogs.

What Happens if a Spider Bites a Dog?

If a spider bites a dog, it can cause a range of reactions depending on the type of spider and the dog’s sensitivity to the venom. Some spider bites may only cause minor irritation, while others can be life-threatening. Symptoms include swelling, pain, redness, lethargy, and severe signs like breathing difficulties. 

Frequently Asked Questions (FAQs)

Final Thoughts

Spider bites on dogs can be a cause for concern, but they are generally not life-threatening. If you suspect a spider has bitten your dog, it is essential to monitor them closely for any signs of an adverse reaction.

Some common symptoms of a spider bite on a dog include swelling, redness, and pain at the bite site. Other signs may include lethargy, vomiting, and loss of appetite. If you notice any of these symptoms, it is essential to seek veterinary care immediately.

Meet Your Experts

Tamsin De La Harpe

Author

Tamsin de la Harpe has nearly two decades of experience with dogs in rescue, training, and behavior modification with fearful and aggressive dogs. She has worked closely with veterinarians and various kennels, building up extensive medical knowledge and an understanding of canine health and physiology. She also spent two years in the animal sciences as a canine nutrition researcher, focusing on longevity and holistic healthcare for our four-legged companions. Tamsin currently keeps a busy homestead with an assortment of rescue dogs and three Bullmastiffs.

Tamsin de la Harpe has nearly two decades of experience with dogs in rescue, training, and behavior modification with fearful and aggressive dogs. She has worked closely with veterinarians and various kennels, building up extensive medical knowledge and an understanding of canine health and physiology. She also spent two years in the animal sciences as a canine nutrition researcher, focusing on longevity and holistic healthcare for our four-legged companions. Tamsin currently keeps a busy homestead with an assortment of rescue dogs and three Bullmastiffs.