Polyurethane ,Formaldehyde ,Ammonia ,Acetone ,Fungicides .The most harmful ones are the Lead based paints .Not only are these toxic when consumed but they also emit fumes which could be equally dangerous for the dogs .Some of the common signs that your dog have come in contact with the paints include : Irritation to skin ,eyes ; difficulty breathing ; diarrhea ; tremors ; etc. A single ingestion of lead based paints can lead to poisoning . Most paints are not branded as being Pet-Friendly ;however by looking at the ingredients one can make a better decision.