Apparently the dose is 1 - 2 pumps per 10kg bodyweight so I guess 1 pump is enough for the average cat. There are 166 pumps per 100ml bottle. You can do the sums to compare
It is applied directly to food - I am always wary as I have never had much luck getting cats to eat food with anything added
I also saw something relating to dogs which I guess is the same for cats. It said that dogs given Viacutan only needed 1/2 dose of preds.