The choice between metformin and glipizide for the treatment of diabetes depends on several factors, including the individual cat's condition, response to medication, and veterinarian's recommendation. Both medications have different mechanisms of action and considerations. Metformin is commonly used in humans with type 2 diabetes and can also be prescribed for cats. It works by improving insulin sensitivity and reducing glucose production in the liver. Metformin is typically used in cats with mild to moderate diabetes or in cases where insulin therapy is not feasible or preferred. It may be used as an adjunct to insulin or as a sole therapy in some cases. However, the effectiveness of metformin in cats is still a subject of debate, and some cats may not respond adequately to this medication. On the other hand, Glipizide is primarily used for the treatment of feline diabetes mellitus, which is typically considered a form of type 2 diabetes in cats. It is not typically used for the treatment of type 1 diabetes in cats, where insulin therapy is the mainstay of treatment. Feline diabetes mellitus is characterized by insulin resistance, impaired insulin production, or a combination of both. Glipizide, as a sulfonylurea medication, works by stimulating insulin release from the pancreas and can help lower blood glucose levels in cats with type 2 diabetes. It is typically administered orally.