A spoonful of PLAIN pumpkin with a meal or few can sometimes firm up stools. If that doesn't do anything or the poo doesn't firm up over time it could be that Nutro doesn't agree with your pup's stomach. In that case a gradual switch to a new food may be in order.
Chase - ringmaster and boyfriend
Rommel - GSD furball
Cloud, Scarlett, Big Girl, and Jarvis - Red Tail (Colombian/Central American) Boa Constrictors