In the early days of Domino's Pizza, the now ubiquitous chain was sued by the makers of Domino's Sugar because.... name. The lawsuit was eventually dismissed after the judge ruled in favor of the pizza company. There really isn't going to be much confusion between pizza and sugar.
That's what I thought about when I read this story about Hormel suing Purina over their use of the phrase "Black Label" when describing dog treats. In the lawsuit documents, Hormel claims that Purina's use of the phrase is likely to cause confusion -- maybe not so much about whether it's people food or dog food, but as to the origins of Purina's dog treats.
For what it's worth, Hormel has been branding their bacon as "Black Label" since 1963... and it does appear that Purina is trying to capitalize on it. But to think that anyone will be confused seems kinda silly to me. And yet, I bet Hormel wins this one -- either outright, or with an out of court settlement.