Why blue cheese is dangerous to dogs
The mould Penicillium roqueforti that creates the blue veins in cheese also produces roquefortine C, a mycotoxin that disrupts nerve signalling in the brain.
Even small amounts can trigger neurological signs in dogs; cats are less commonly affected but can still be poisoned if they ingest the cheese.
This toxin is not destroyed by refrigeration and remains active in the cheese until it is eaten.
Why speed matters
Delaying care significantly worsens outcomes. Some signs appear hours or days later, so "looks fine right now" is not a reason to wait.
Symptoms of blue-cheese-roquefortine poisoning
- trembling or shaking starting 30 minutes to 2 hours after eating blue cheese
- violent muscle tremors that may progress to full seizures in severe cases
- restlessness and inability to settle within an hour of ingestion
- rapid breathing and an elevated heart rate during tremor episodes
- collapse or inability to stand if seizures are prolonged
What to do right now
- call your vet or the ASPCA Animal Poison Control Center at 888-426-4435 or Pet Poison Helpline at 855-764-7661 immediately
- bring the cheese packaging or a photo so the team can identify the mould type and estimate toxin exposure
- note the approximate amount eaten and the time of ingestion to help the vet assess severity
- do not induce vomiting; if the pet is already tremoring or seizing, attempting to induce vomiting risks aspiration of stomach contents
- keep the pet in a quiet, dim room on a soft surface and prevent them from falling or injuring themselves while tremors occur
Sources & further reading
- ASPCA Animal Poison Control — pet poison database & dosage references
- Pet Poison Helpline — toxicology triage guidelines
- Merck Veterinary Manual — toxicology monographs
- Vets Now (UK) — emergency toxicosis guidance
Other poisonings with overlapping signs
- Moldy Food, Compost & Bin Raids — another common emergency
- Liquid laundry detergent poisoning in dogs and cats — another common emergency
- Yew Plant Toxicity in Dogs and Cats — another common emergency
Owners also ask
- How much moldy bread is dangerous for a cat?
- My 3 kg Chihuahua licked a puddle of concentrated laundry detergent — is his small size a bigger problem?
Frequently asked questions
Is Blue Cheese Toxicity in Dogs and Cats poisonous to a dog or cat?
The mould Penicillium roqueforti that creates the blue veins in cheese also produces roquefortine C, a mycotoxin that disrupts nerve signalling in the brain.
What are the symptoms of blue-cheese-roquefortine poisoning?
trembling or shaking starting 30 minutes to 2 hours after eating blue cheese; violent muscle tremors that may progress to full seizures in severe cases; restlessness and inability to settle within an hour of ingestion; rapid breathing and an elevated heart rate during tremor episodes
What should I do if my pet ate Blue Cheese Toxicity in Dogs and Cats?
call your vet or the ASPCA Animal Poison Control Center at 888-426-4435 or Pet Poison Helpline at 855-764-7661 immediately bring the cheese packaging or a photo so the team can identify the mould type and estimate toxin exposure note the approximate amount eaten and the time of ingestion to help the vet assess severity
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