Failing to establish a healthy meal routine is one of the most common mistakes pet owners make. If food is always available, pets who graze throughout the day tend to overeat, which could lead to obesity. Pets who are fed only once per day may develop bilious vomiting syndrome, which occurs when stomach inactivity aggravates the bile reflux, causing bile to enter the stomach. Once bile enters the stomach, your pet may vomit or, if they don't, they may develop gastric reflux. A twice-per-day feeding schedule is ideal in most situations, though some pets may benefit from smaller portions spread across more feedings. If you are unsure what schedule is best for your pet, talk to your vet.