It doesn't mean the food isn't good or that your vet does not have your dogs best interests in mind. However, it usually means spending far more money than you need to. Feeding your dog is about proper Chihuahua care and seeing he is getting the proper diet and nutrition, not about how much it costs.
The Basics
Every breed of dog has its own special nutritional and dietary needs. As an owner your job in Chihuahua care is to make sure he is getting those required things. These nutritional and dietary needs are something that is determined by a dogs breed and genetics. That means that dogs need a diet that is similar to what they would eat in their native environment.
The Chihuahua is native to Mexico, specifically, Chihuahua, Mexico. In Mexico there are rain forests and jungles that supplied the diet for the breed originally. Chihuahua's also used to be a work dog in the temple where he would chase rodents, which also ending up being part of their diet. Besides that they often ate tropical fruits, boar meat and poultry.
Your Dog's Dietary Needs
Chihuahua's should have food that has a lot of calorie and protein content. They are very active dogs and as such burn plenty of calories throughout the day. They need the protein to ensure their muscles and overall body remains fit and healthy. It is also a good idea to feed an older Chihuahua a food that includes antioxidants to help keep him healthy. Do not give him excess treats and try to stick to healthy, protein rich treats when you do give them to him. You should make sure part of your Chihuahua care includes feeding your Chihuahua regularly and being careful to not overfeed or underfeed him.