By Walt Hickey Pet Food People are beginning to cut back on the quality of pet food for their beloved animals, with premium dry dog food shedding 2.9 percentage points marketshare year over year in the quarter ending in July. One reason is that pet food is just as susceptible to price inflation as people food, and prices are up 11 percent compared to a year ago. The rate of sales growth is slowing down, with premium pet food sales up 8.5 percent in the second quarter, down from 21.3 percent growth in the same period of last year. According to Smucker, which recently sold off Kibbles ‘n Bits, 9Lives and Rachael Ray Nutrish to Post Holdings, sales in their pet food segment were down