When Hobos Attack. The Dangerous Truth About Hobo Spider Bites On Cats


The hobo spider (Eratigena agrestis) is a medium-sized spider belonging to the funnel-web spider family Agelenidae. Hobo spiders have an elongated body up to 14mm in length and are yellowish-brown in color with darker markings on the abdomen. They are found primarily in the Pacific Northwest region of the United States and parts of Western Canada (Facts about Hobo Spider Bites).

Hobo spider bites can be medically significant in humans, with symptoms ranging from minor itching and redness to necrosis and tissue damage in rare cases. However, there is debate about whether the hobo spider venom is toxic enough to cause such severe reactions (Hobo Spider).

This article explores what happens when a hobo spider bites a cat. Cats may be at risk for hobo spider bites if living in areas inhabited by these spiders. We will analyze the potential effects of hobo spider venom on cats and what pet owners should do if their cat is bitten.

Hobo Spider Overview

Hobo spiders (Eratigena agrestis, formerly Tegenaria agrestis) are medium-sized spiders typically measuring 7-14 mm (0.3–0.5 inches) in body length. They have an elongated body with brown coloring and darker brown bands on the legs. Hobo spiders are found primarily in the Pacific Northwest region of the United States and Western Canada. Their native range is Northern Europe.

Hobo spider bites are generally not considered medically significant for humans. Some older research suggested hobo spider bites could cause minor skin lesions or systematic reactions, but newer research indicates the venom has low toxicity (Utah State University Extension). Bites may cause mild burning, redness, and irritation but are less severe than brown recluse spiders. Hobo spiders are not aggressive and only bite when feeling threatened or provoked.

Hobo Spider Bites in Cats

There are few documented cases of hobo spider bites in cats, but they can occur (Source 1). Hobo spider venom is toxic to cats, though not as toxic as to humans. If a cat is bitten, the area will likely become red and itchy (Source 2).

Symptoms of a hobo spider bite include:

  • Red, itchy wound at bite site
  • Swelling around bite
  • Blistering or ulcers
  • Tissue damage or necrosis

If a cat has been bitten by a hobo spider, take it to the vet immediately. The vet will clean and disinfect the wound, and may prescribe antibiotics, pain medication, and other treatments to prevent infection and tissue death (Source 3). With prompt veterinary care, most cats recover fully from hobo spider bites.

Venom Composition

The venom of the hobo spider contains several potent neurotoxins that affect the nervous system of the victim. The main neurotoxins found in hobo spider venom include acetlycholinesterase, sphingomyelinase D, and delta-actitoxinHf1a (based on research). These neurotoxins disrupt communication between nerves and muscles, leading to symptoms like muscle spasms and paralysis.

Compared to some other spiders, the hobo spider’s venom is not considered highly toxic. For example, the venom of the black widow and brown recluse spiders is known to contain more potent neurotoxins and cause more severe reactions (according to studies). However, the hobo spider’s venom can still be dangerous, especially to smaller animals like cats.

Bite Severity

The severity of a hobo spider bite can vary greatly depending on the location of the bite, the amount of venom injected, and the sensitivity of the individual. Cats tend to experience more severe reactions than humans.

For cats, the bite location is a major factor influencing severity. Bites on the face or other sensitive areas often provoke stronger reactions. Bites on areas with thinner skin and closer blood vessels also enable faster venom absorption (Healthline).

The amount of venom injected impacts severity too. More venom leads to a more intense reaction. Male hobo spiders tend to inject more venom as their fangs are larger (Medical News Today).

Finally, some cats have higher sensitivity and allergic reactions to the venom compounds. This can greatly exacerbate bite symptoms.

Compared to humans, cat bites tend to be more consistently problematic. Cats seem to experience more intense inflammatory reactions to the venom. Human bites show high variability, with most being minor and some being medically significant.

First Aid for Cat Bites

If your cat is bitten by a hobo spider, the first step is to care for the wound. Gently clean the bite area with mild soap and water to remove any venom on the surface. Avoid using hydrogen peroxide or alcohol, as these can damage tissue. Apply a cool compress, wrapped in a towel, to the bite for 10-15 minutes to reduce swelling and pain. Bandage the wound lightly to protect it if needed.

To manage pain, over-the-counter pain medication formulated for cats, such as acetaminophen or aspirin, can be given according to dosage instructions. Never give your cat human medications. Pain medication will help relieve discomfort until your cat can be seen by a veterinarian. Ensure your cat has access to fresh water and limit activity to prevent worsening the bite.

Monitor your cat closely for signs of serious reaction, like difficulty breathing or excessive swelling, which requires emergency veterinary care. Otherwise, make an appointment with your vet as soon as possible after the bite for proper examination and continued care.

Diagnosis and Treatment

If a cat has been bitten by a hobo spider, a veterinarian will diagnose based on the cat’s symptoms and the owner’s account of the bite. There are no definitive tests to confirm a hobo spider bite. The vet will look for symptoms like pain, redness and swelling around the bite, and tissue damage or necrosis. They may take a sample of the wound to check for bacteria [1].

Currently, there is no approved antivenom for hobo spider bites. Treatment involves supportive veterinary care to address symptoms and complications. The vet may give the cat antibiotics, pain medication, anti-inflammatories, and fluid therapy. In severe cases, surgery may be needed to remove dead tissues or drainage tubes inserted to remove fluids or pus from the wound [2].

Cats will need to stay at the vet clinic for monitoring and treatment of any progression of symptoms. With prompt veterinary care, most cats recover fully from hobo spider bites [1].

[1] https://www.atlanticvetseattle.com/how-to-keep-your-cat-safe-from-hobo-spiders/
[2] https://www.vetinfo.com/treating-spider-bites-on-cats.html

Long-Term Outlook

The long-term prognosis for a cat after a hobo spider bite depends on the severity of the bite and how quickly treatment is administered. With prompt veterinary care, most cats fully recover from hobo spider bites within 2-4 weeks.

Mild bites may heal completely with minimal scarring. More severe bites can cause necrosis and deep wounds that take longer to heal. Extensive tissue damage may result in loss of fur and scarring at the bite site. However, cats’ skin often heals remarkably well.

According to veterinarians, the venom from a hobo spider bite can continue spreading for up to 24 hours if left untreated. Anti-venom and other medications help neutralize the venom and prevent further progression. With appropriate treatment, long-term damage can be minimized.

In rare cases with a highly toxic reaction, a hobo spider bite can cause chronic health issues for a cat. Kidney or liver damage may occur. The cat may experience ongoing pain or mobility issues if muscles or joints were impacted. But full recovery is still possible with careful follow-up care and rehabilitation.

Overall, the prognosis is generally good for cats after a hobo spider bite as long as the reaction is identified quickly and appropriate treatment begins within the first day. Most cats bounce back fully with their normal energy levels and quality of life.


There are ways to prevent hobo spider bites in cats. One way is by spider proofing your home. This involves sealing any cracks or openings that spiders could enter through. You can apply caulk around windows, doors, pipes, vents, and any holes in your home’s foundation. Installing door sweeps or screens on open windows can also help keep spiders out.

You should also remove any clutter stored near your home’s foundation, in your garage, or in storage areas, as these provide hiding spots for spiders. Keeping your home clean and vacuuming regularly can help remove any spiders that make it inside. Using essential oils like peppermint, tea tree, citrus, or eucalyptus can deter spiders as well.

When outside with your cat, avoid areas that may be infested with hobo spiders like wood piles, rock walls, debris, overgrown plants, and leaf litter. Keep your lawn mowed and trim vegetation back from the house. Placing sticky traps around the perimeter of your home can also catch spiders.

Checking your cat regularly for any spider bites and brushing its fur after being outside can help detect bites early. Speak to your vet about preventative treatment options as well.


Although hobo spider bites are not commonly reported in cats, they can still occur. The venom can potentially cause issues like necrosis and muscle/tissue damage at the bite site. Cat owners should be vigilant about spiders in and around the home, especially in crawl spaces, basements, and wood piles where hobos like to nest.

If you suspect your cat has been bitten by a hobo spider based on symptoms, promptly take it to the vet for evaluation and possible treatment with antivenom. Clean the wound, apply ice, and monitor your cat closely until you can be seen. Prevent bites by keeping your home and yard free of clutter and sealing cracks that allow spiders to enter.

While hobo spider bites can be concerning, the good news is cats tend to recover well with proper care. Be proactive about pest control and awareness of venomous spiders in your region. With some simple precautions, you can help keep your feline friend safe.

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