How can you tell if something has horse meat in it?

Question: How can you tell if something has horse meat in it?
- Keywords:
  animal,
  horse,
  topical
Asked by gotanygrapes to Alessandro, Angela, Claudia, Marina, Phil on 16 Mar 2013.
- Marina De Vos answered on 16 Mar 2013:
  
  You can test for horse dna.
  
  With only a small portion of horse meat in a product, you would not taste. The taste of horse meat is not as different from beef to notice the difference if it appears in small quantities.

Question: How can you tell if something has horse meat in it?