PupkeeperToxicEmergency
Black widow and brown recluse spiders and dogs: what to do
Most spiders are only mildly venomous, but black widow and brown recluse bites can cause severe muscle pain, paralysis or skin wounds.
If your dog ate or touched this, call your vet or a pet poison line now
United States
Poison lines in other countries: United Kingdom, Australia, Canada, New Zealand
What to do now
- Call your vet or a pet poison line now.
- If your dog only played with an ordinary spider, move it away and watch for signs.
Signs to watch for
- Severe muscle pain or cramping (black widow)
- Wobbly walking, tremors or paralysis (black widow)
- Drooling, vomiting or diarrhea
- Painful, itchy bite with a bull's-eye sore (brown recluse)
- Fever and lethargy
- Bleeding problems
Why
The female black widow's venom affects muscles and nerves; brown recluse venom damages skin and can affect blood clotting. There is no antivenom for the brown recluse.
Sources
- Pet Poison Helpline: Spiders
- Pet Poison Helpline: Black Widow Spider
- Pet Poison Helpline: Brown Recluse Spider
Guide reviewed 9 October 2026.
General information from the sources above, not a diagnosis. When in doubt, call your vet.