As with any changes to your pet’s diet, adding a Zest & Pep supplement has the potential to cause mild digestive upset whilst the digestive system adapts to the new addition to the diet. It is unlikely that digestive upset occurs from Zest & Pep supplements, however if digestive upset occurs in your pet, we recommend that you pause supplementation until the digestion settles. Then you can resume supplementation by introducing the supplementgradually, which gives your pet’s sensitive digestion chance to adapt to the addition to the diet.