http://www.bbc.co.uk/news/uk-21375594
So the typical Lasagna is made from minced beef, however it seems that somewhere in production the beef has been supplemented, and in some cases replaced with horse meat, without the knowledge of the producer. Now I understand that some people may eating horse and it does not bother them.
how would you react if you found that something you bought that was labeled as Beef but actually contained Horse ?
Personally, I would not let it bother me in the slightest (that it was horse) my only concern would be that the animal was raised and treated properly prior to slaughter.