As people’s waistlines expand, so do their pet’s, and feline obesity continues to rise. When cats overeat and gain weight, it affects their digestive system and gut microbiota. About 60% of cats in the US are overweight, which can lead to health problems like diabetes and chronic inflammation. A study found that as cats overeat and gain weight, gastrointestinal transit time is reduced, and so is digestive efficiency. There are about two million pet and street cats in Israel, and even those who live outside seem quite well fed from garbage cans and food left outside by “cat ladies.” A low fecal pH indicates poor absorption of carbohydrates and fat. Understanding the metabolic and gastrointestinal changes that occur with weight gain and obesity in pets could help with future prevention and treatment plans.