As the Chihuahua puppy reaches maturity it is time to begin transitioning to an adult maintenance diet. As an adult, the Chihuahua has finished growing and is not burning fuel like she did as a pup. The Chihuahua's nutritional needs also change; adult formulas reflect this shift in protein, fat, vitamin, and mineral requirements.
When changing foods, gradually incorporate the new food with the old food over a period of seven to ten days. Sudden changes in diet can cause severe gastrointestinal distress.
Appropriate foods for the adult Chihuahua include those designed for toy or small breeds, which provide the correct balance of nutrients for an adult dog but in kibble size that is easily managed by the Chihuahua's jaws. Adult toy-and small-breed foods often address the extensive dental problems toy breeds tend to suffer by producing a crunchy kibble that helps reduce tartar.
Adult Chis can be fed two small meals, twice a day. If you've adopted a rescued Chihuahua and don't know how much to feed her, you can administer the free-feed test. If your Chihuahua is not overweight, allow her to eat undisturbed from a half-cup serving of dry dog food. After twenty minutes, pick up the leftovers and record how much your dog ate. Continue this for three or four meals until you have a basic idea as to what your dog is eating.
If your Chi is overweight, you'll need to consult with your veterinarian as to how much your Chihuahua should be eating and ways to help reduce her weight.