Alpo recalls are generally announced on the manufacturer's website and on the website of the U.S. Food and Drug Administration. You can also sign up for an email service to alert you automatically of any dog food recalls.
There are several private email services that alert consumers about pet food recalls. These services generally work by emailing you about any recall that occurs, not just Alpo. Dog Food Advisor and the Dog Channel both offer free alerts as of 2015.
Dog food recalls, especially those of popular brands such as Alpo, are also usually widely covered in the media. During the last major recall of Alpo, most major news sources covered the story. Magazines or other media that cover pet-related issues may be more likely to report such occurrences.
If your dog food is recalled, stop feeding it immediately and take your dog to the vet for a check, even if there are no symptoms yet. Keep the food on hand for a few weeks in case you need it to be tested to confirm a diagnosis. If you think your pet food is making your dog sick but there is no recall in effect, take your dog to the vet and report the situation to the FDA.