My dog found and ate some old, mouldy cloves — is that dangerous?

Yes, that adds significant risk. Cloves themselves contain eugenol, which is irritating, but mould introduces mycotoxins that can cause vomiting, tremors, or even liver damage. Watch your dog closely for signs like drooling, lethargy, or loss of appetite over the next 24 hours. Do not wait for symptoms to appear if you know a mouldy spice was eaten. Contact your veterinarian promptly to discuss what your dog ingested and whether an examination is needed.