Who is Mustard Dog? He’s just a good boy having a bad day. Everything seemed fine as he was having lunch, but then there was a rumba-down-unda. Then this happened and the rest is history. Poor Mustard Dog!
In any case people are always asking…. Is Mustard bad for dogs? Well… Yes, mustard is bad for dogs. Mustard is made up of mustard seeds. Mustard seeds primarily contain glucosinolates – a toxic component of mustard. Mustard seeds, when consumed in a large amount could cause diarrhea, nausea, vomiting and abdominal pain.