Pet bird nutrition — all-seed diets deficient in vitamin A, Ca:P imbalance
Source: Merck Veterinary Manual (merckvetmanual.com), a copyrighted professional veterinary reference. Per COPYRIGHT_POLICY §3, the points below are paraphrased derived fact summaries: numerical values and proper nouns are preserved from the source, but sentences are rewritten and not quoted verbatim.
Claims
*[Paraphrased derived summary — non-Open-Access source.]* Hypovitaminosis A causes squamous metaplasia of epithelium within the oropharynx, choana, sinuses, GI tract, urogenital tract, reproductive tract, and uropygial gland, as well as hyperkeratosis of the feet. *[Paraphrased derived summary — non-Open-Access source.]* All-seed diets, and even mixed diets of 1/2 seeds and 1/2 pellets if not portion-controlled, are deficient in vitamin A. *[Paraphrased derived summary — non-Open-Access source.]* Seed-based diets are well known for their calcium:phosphorus imbalance and amino acid deficiencies. *[Paraphrased derived summary — non-Open-Access source.]* Sunflower seeds, which many psittacines preferentially select, are low in calcium, deficient in essential amino acids, and high in fat. *[Paraphrased derived summary — non-Open-Access source.]* High-fat diets (seeds, nuts, and many table foods), overabundance of food, and a sedentary lifestyle are contributing factors to illness. *[Paraphrased derived summary — non-Open-Access source.]* Iron storage disease is associated with excessive intake of dietary iron. *[Paraphrased derived summary — non-Open-Access source.]* Certain vitamin C-rich foods, such as citrus fruits, increase dietary iron uptake. *[Paraphrased derived summary — non-Open-Access source.]* Current dietary iron recommendations for toucans and mynahs are < 50-100 ppm.