Petco in Mt Vernon is a trusted one-stop pet shop offering quality food, supplies, and essentials for dogs, cats, and other pets. The store provides huge savings on items like cat litter and has lots of different options. It features an aquatics department and offers services including a vaccination clinic, dog training, and a self-service dog wash. The staff is described as very sweet, helpful, extremely knowledgeable, understanding, and super helpful. Specific services praised include positive reinforcement dog training, with one customer noting it made an amazing difference for their pet. The store is recommended as a great place for all pet-related shopping, providing a great experience.