When switching dog food, if it isn't done correctly, it can cause your dog to become sick.
They can get an upset stomach and diarrhea if switched over to a new brand too abruptly.
Chihuahuas can be finicky eaters. If you continually change their diet, this will only make them more picky.
It is best to decide on a brand and then stick to that.
Some of their fussiness may be because they are eating too many people treats and therefore do not want to eat their own.
If that seems to a problem, then simply ignore those begging eyes, and cut back on the treats!
Whether you have a new puppy or an older Chihuahua, if for any reason you do need to change their diet, do it over a period of several days.
Add a little bit of the new brand and mix it into the old, using no more than ¼ parts of the new food.
Each day lessen the old by raising the amount of the new.
Take close to a week to change completely over.
If you are getting a new puppy and do not intend to keep your pup on the food it has been raised on, ask the breeder for a small bag of his current brand, so you will have some to mix it with.
If you need to quickly switch brands, due to an illness or some other emergency, then you can do a 50/50 mix for a couple of days.
However, it is better to try and complete the switch over the course of a week.