Here’s What To Do If You Find A Spider Bite On Your Dog
First things first, don’t panic.

If your dog gets bitten by a spider, first things first, don’t panic. Most spider bites are non-venomous and, aside from minor irritation around the bite, are totally harmless.
There are a few types of spider bites that can be potentially dangerous for your dog, though. So it’s important to pay close attention to a spider bite on a dog, and look for any reactions (delayed or otherwise) post-bite.
We spoke to Leah Feusse, a veterinary nurse with DodoVet, for more insight on spider bites and dogs, types of spider bites that can be dangerous and when to call the vet.
What to do if you notice a spider bite on your dog
If your dog gets a spider bite, it’s best to call your veterinarian right away.
“If you can catch the spider or take a good photo of it, that can potentially help your veterinarian identify the type of spider and its venom in order to develop the best possible treatment plan for your dog,” Feusse told The Dodo.
Non-venomous bites will appear as small red bumps, with mild irritation, redness and possible swelling, and can be treated similarly to mosquito bites (by applying a cold compress on the bite and applying aloe vera gel or a paste of baking soda and water), and will be mainly focused on itch relief (some dogs might not even notice the bite at all!).
But because your dog’s reaction to a venomous spider bite could be delayed and may first appear as harmless as those from non-venomous spiders, it’s best to call your vet right away to determine what kind of bite it is.
Signs of a spider bite on a dog
Your dog may have a variety of reactions to a spider bite, and depending on how serious it is, symptoms might not even begin until days later.
For non-venomous bites, while it may be a little painful for your dog, he’ll likely be more concerned with how itchy he is where the bite occurred. As mentioned above, signs include small red bumps, redness, minor irritation and possible swelling.
“Other spiders’ bites, like the brown recluse, are not painful at all, but their venom can cause tissue damage [and] a localized site reaction hours, days or even weeks later,” Feusse said. “Localized site reactions can be red, or look like a bullseye, and can eventually blister and burst, leaving a deep wound behind.”
Black widow spiders are also venomous. The bite can be moderately painful, and most dogs will only have mild clinical signs with moderate redness and swelling at the location of the bite.
“Usually severe signs develop within 2–8 hours,” Feusse said. “A dog having a severe reaction may develop muscle pain, rigidity and cramping, tremors, agitation, painful or hard abdomens, vomiting, and diarrhea.”
Spider bites that could be harmful to your dog
There are three documented types of spider bites that can cause health issues in dogs, according to Feusse:
- Brown recluse spider: Reactions to this bite can cause vomiting, chronic skin lesions, bleeding or bruising, clotting issues, and organ damage in a small amount of dogs.
- Hobo spider: Reactions will be similar to those of the brown recluse spider.
- Black widow spider (female): The most dangerous of the three, 85 percent of dogs bitten by black widows will have a reaction that affects their nervous system. Reactions include muscle pain, rigidity and cramping, tremors, agitation, painful or hard abdomens, vomiting, and diarrhea. Small dogs or dogs with weakened immune systems can be at a greater risk for severe reactions.
Spider bite treatment options
If your dog’s having a localized site reaction to a non-venomous bite, you might notice him licking or chewing the area.
“Your vet can prescribe an antihistamine and/or anti-inflammatory to help relieve the discomfort,” Feusse said. “If the bite blisters and bursts, the open wound should be evaluated by your vet, as it may need minor wound care or regular bandage changes and antibiotics to prevent infection.”
If your dog is bitten by a black widow spider, your pup will need IV fluids, pain medications and muscle relaxers. And if the bite causes a severe reaction to the nervous system (as mentioned above), your vet will likely recommend heading to an emergency hospital that may have access to antivenin, a medication containing antibodies against specific poisons, especially those in the venom of spider bites, snakes and scorpions.
“With spiders, like the brown recluse, that can cause local site reactions, treatment is usually after the bite has blistered and burst,” Feusse said. “Veterinarians will treat the wounds with routine cleanings, bandages and cold compresses. They may also prescribe antibiotics to prevent a secondary infection and relieve discomfort.”
In summary: Watch out for spiders, friends. While many spiders can be friendly and harmless, you don’t want to run across a venomous spider when you’re out for a walk with your dog. But if you do, calling your vet right away is advised.
Want access to a vet 24/7? With DodoVet, you can connect via video chat, phone or text with an empathetic veterinary expert who can help you be the best pet parent you can be. Say goodbye to Dr. Google and have all your pet parent questions answered anytime, anywhere. Learn more here.