There is no magic date that all dogs need their food decreased. Adults don’t need to be fed three times a day like a pup, but the amount they eat will vary from dog to dog. For ex, my shihtzu ate three very tiny meals per day. As she reached adulthood, the amount increased, but the frequency did not. I have not found my crew needed reduced food simply by virtue of spay/neuter, but rather based on their particular activity levels, and those change depending on the weather. All my dogs, from pup to senior eat an all life stage food.
