Task: Sentiment Analysis
Input (English): I had good results with this product six months ago.  However, a second purchase that I just opened caused all of my three dogs to vomit within minutes of eating the product.  I removed other items from their diet to be sure and it did it again, instantly. I contacted the company about it and they have claimed no other problems exist(suggesting I must have tainted the product or have exposed it to an environment making the dog snacks unstable, or the company I purchased them from somehow did something to the product. Hmm: sounds troubling to me, especially from the factory.). I have seen other issues out there regarding this product, which vary.  Use your own methods of making a control group, but be sure to see they have proper bowel movements and are not vomiting after you feed them the product.  Secondly, Greenies.com(the Nutro Company) will not honor purchases made through unauthorized vendors.  Amazon directly is an "authorized vendor".  "Monster Pets" is not authorized to resell these items and only those vendors listed on their website are "authorized".  They will only help you return/refund something if it was purchased through an "authorized" vendor.  This now makes me leery of items purchased through "Amazon Marketplace", particularly food items.  Buyer beware!  Caveat emptor! 
 Polarity: Positive
Output (English): False