Pet bird nutrition — all-seed diets deficient in vitamin A, Ca:P imbalance
The text below is reproduced verbatim from the first-hand source (Merck Veterinary Manual).
> Hypovitaminosis A causes squamous metaplasia of epithelium within the oropharynx, choana, sinuses, GI tract, urogenital tact, reproductive tract, and uropygial gland as well as hyperkeratosis of the feet. All-seed diets and even mixed diets of ½ seeds and ½ pellets (if not portion controlled) are deficient in vitamin A. > Seed-based diets are well known for their calcium:phosphorus imbalance and amino acid deficiencies. Sunflower seeds, which tend to be selected preferentially by many psittacines, are low in calcium, deficient in essential amino acids, and high in fat.
Source: pdf-raw/exotic-toxicology/pet-bird.txt (first-hand professional veterinary reference, tag-stripped).
Claims (verified C1 substrings of source_file)
Hypovitaminosis A causes squamous metaplasia of epithelium within the oropharynx, choana, sinuses, GI tract, urogenital tact, reproductive tract, and uropygial gland as well as hyperkeratosis of the feet. All-seed diets and even mixed diets of ½ seeds and ½ pellets (if not portion controlled) are deficient in vitamin A.Seed-based diets are well known for their calcium:phosphorus imbalance and amino acid deficiencies. Sunflower seeds, which tend to be selected preferentially by many psittacines, are low in calcium, deficient in essential amino acids, and high in fat.