Natural Instinct ZooLac Propaste stabilises the digestion and balances the bacterial flora in the intestinal tract by working with the good bacteria and your pet's immune system. Natural Instinct ZooLac Propaste contains several types of good and naturally occurring bacteria with a well defined effect. The overall effect is therefore very broad and ensures a great result for your pet. It's unique composition works mainly by preventing harmful bacteria from attacking the intestinal wall, while the good bacteria attack the harmful ones. The attack is a naturally occurring action that limits the growth of harmful bacteria. The action means harmful bacteria cannot develop any resistance, which is often the case with antibiotic treatments.