excessive licking - probably an allergy?

[cattledogkisses]

We switched G to a different food about a week or two ago, and lately she's been obsessively licking, mostly her front paws/legs.  There doesn't seem to be any visible irritation or injury there.  The only thing making me doubt is that we've fed her this food (Blue Buffalo) in the past without any issues. 

[Deleted]

Sudden, obsessive licking of the front paws can also be a sign of pain elsewhere. It was the first visible sign of my dogs neurological disorder. Is she doing anything else out of character?

[Deleted]

What ingredients are in the food? Dogs can develop allergies to foods that they were once okay on.