The firms that market these products defend them by claiming that they have been marketed for many years. However, a successful marketing history alone does not establish that they are safe or effective. It establishes for the most part that the firms have successful marketing strategies. I t is the opinion of many expert avian veterinarians that most of these over the-counter products do more harm than good. Wearing both of my hats as a practicing avian vet and a veterinary medical officer at the FDA, I agree.
Birds are experts at hiding their symptoms of disease.
This is a defense mechanism developed to insure their survival in the wild. They often do not appear ill until their disease state is advanced. They usually have minimum body fat, and thus have little energy reserve. So, if they get sick, they go downhill very rapidly. If you experiment with over the counter medicines, by the time you realize the bird is really in trouble and seek a veterinarian's advice, it might be too late to help your pet.