An e-commerce business by the name of "The Dawg's Biscuits" is selling a line of dog treats that claims to help dogs calm down from stress. The product named, "Calm Dog" is being marketed a month prior to the Independence Day celebrations here in the United States, to help dogs cope with the sounds of fireworks.

According to the website:

The oats, banana and chamomile help Serotonin production, Serotonin being the body's natural relaxant. This is also helped by the B vitamins in Brewer's Yeast, all helping to give a slightly sleepy-happy feel without any manufactured chemicals.

I haven't purchased any, so I can't tell you if it makes my dogs any more mellow. You can order some online from its catalog for £3.25.