Pavlov commands a dog using prime bits of fatty food? (7)

I haven't cracked this one yet — but the brilliant team at Fifteensquared have:

pAVlOv CommAnDs a dOg – taking the letters in positions 2, 3, 5, 7, 11, 13 and 17, i.e. the primes. Fed has used this device before (as have others) but to get all the way to 17, with a phrase that makes sense, is very impressive