My dog ate blue-green algae (pond scum) — what should I do?
🚨 RED — Go to an emergency vet NOW
Cyanotoxins (microcystins, anatoxins) can kill within an hour.
What to do now
- Call an emergency vet or animal poison control right now, even if your dog seems fine — signs can be delayed.
- Head to the nearest emergency vet; call ahead on the way.
- Remove any remaining material and keep packaging/labels — the vet will want product names and amounts.
- Do not induce vomiting unless a vet or poison-control expert tells you to.
- Note the time it was eaten, roughly how much, and your dog's weight.
Why it's a problem
Cyanotoxins (microcystins, anatoxins) can kill within an hour.
Symptoms to watch for
Vomiting, diarrhea, drooling, tremors, collapse, liver failure.
When: 15 min - hours
⚠️ Rinse the coat with clean water; don't let the dog lick it.
Frequently asked questions
Is blue-green algae (pond scum) dangerous for dogs?
Yes. Cyanotoxins (microcystins, anatoxins) can kill within an hour. Treat it as an emergency and contact an emergency vet or animal poison control immediately.
What are the symptoms if my dog ate blue-green algae (pond scum)?
Vomiting, diarrhea, drooling, tremors, collapse, liver failure.
How soon do symptoms appear after a dog eats blue-green algae (pond scum)?
15 min - hours
Is there anything else to know about blue-green algae (pond scum)?
Rinse the coat with clean water; don't let the dog lick it.
What should I do if my dog ate blue-green algae (pond scum)?
Call an emergency vet or animal poison control right now, even if your dog seems fine — signs can be delayed. Head to the nearest emergency vet; call ahead on the way.
Who can I call for help?
ASPCA Animal Poison Control (888) 426-4435 or Pet Poison Helpline (855) 764-7661, both 24/7 (fees may apply), or your nearest emergency vet.
Dose guidance
No reliable dog-specific threshold is published for home use, so any amount should be discussed with your vet or a poison hotline.
Sources
Last verified against these sources: 2026-10-13. Where sources disagree, PawPanic uses the more conservative guidance.
Also known as: algae bloom, pond water, cyanobacteria · Category: Garden · Last reviewed 2026-10-14