Monitor — routine vet appointment
Dog suspected spider bite (UK)
Most UK spider bites are harmless and self-limiting; monitor for swelling, lameness, or signs of allergic reaction and contact the vet if concerned.
Recognise the signs
- Localised swelling, redness
- Mild pain
- Sometimes two puncture marks
- Rarely systemic signs (allergic reaction)
First aid steps
- Bathe gently with cooled boiled water.
- Cool compress 10 minutes.
- Monitor for spreading swelling, lameness, or distress.
- Phone the vet if concerned, particularly for facial swelling.
Do NOT
- Do not give human painkillers.
- Do not assume every skin lump is a bite — many are infections.
When to phone the vet immediately
- Spreading swelling, particularly on the face
- Allergic reaction signs
- Persistent pain or non-healing wound
- Lethargy, vomiting
Signs that can usually wait for a routine appointment
- Mild localised swelling in a bright dog usually settles in 24-48 hours.
Common causes
- False widow spider (occasionally medically relevant)
- Garden spiders (rarely cause issues)
- Most UK spider bites are misidentified other causes (insect sting, skin infection)
What the vet will need to know
- Witnessed bite or spider seen
- Photo of the area
- Other current signs
Aftercare
- Most resolve without treatment.
- Vet review for non-healing or progressively swelling wounds.
Frequently asked questions
Are UK spiders dangerous to dogs?
Almost never. Most spider bite suspicions turn out to be other causes. False widow bites can occasionally cause local reactions.
Should I get the spider identified?
Only if you have a clear photo or specimen — not worth chasing. Treat the wound regardless.
Will my dog need antivenom?
Not in the UK — spider antivenom is not used routinely here, and bites rarely warrant it.