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Avian nutrition has greatly improved in the past decade. Pellets and even organic formulated diets are now available, and domestically raised psittacine juveniles generally accept these readily. However, the nutritional requirements for individual psittacine species are still largely unknown. Many of the illnesses seen in pet birds have their basis in malnutrition. This includes hepatic disease, renal insufficiency, respiratory impairment,
musculoskeletal disease, and reproductive problems. For information on appropriate nutrition in pet birds, see
Birds: Overview. |
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Vitamin A Deficiency: |
| This is frequently unrecognized in its subclinical forms in pet birds. White plaques (hyperkeratosis) in and around the mouth, eyes, and sinuses are typical. Blunting or absence of the choanal papilla is common. Chronic epithelial conditions, eg, pododermatitis, sinusitis, and conjunctivitis, that have been refractory or recurrent often have vitamin A deficiency as the primary etiology. Parenteral vitamin A can be given IM at 100,000 U/kg. Vitamin A precursors, such as
spirolina, sprinkled daily over the food are a way to supplement birds deficient in vitamin A. The diets of all caged birds should be evaluated for vitamin A content. |
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Iodine Deficiency: |
| Goiter, or thyroid hyperplasia, was previously a serious problem of pet budgerigars and still occurs in certain areas. The thyroid gland in budgerigars is normally ~3 mm long but can enlarge to ≥1 cm. Classic signs include respiratory stridor, wheezing, or clicking due to the pressure of the thyroid on the syrinx. Regurgitation is seen in some severe cases, and the right jugular vein may be engorged; these signs are caused by mechanical obstruction of the thoracic inlet.
Affected birds tolerate stress poorly. Lugol’s iodine (1 drop/250 mL of drinking water) can be used until conversion to a pellet or seed is accomplished and clinical signs have subsided. |
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Calcium, Phosphorus, and Vitamin D3 Imbalance: |
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Seed diets have been 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. Safflower seeds are actually higher in fat content than sunflower seeds, contrary to popular belief, and also contain inadequate amino acids and calcium. |
Acute Hypocalcemia in African Gray Parrots:
| This syndrome is characterized by weakness, tremors, and seizures. The exact etiology is unknown, although parathyroid hormone abnormalities in this species are being studied. Parenteral calcium may effect immediate improvement. Differential diagnoses include heavy metal toxicosis, trauma, and idiopathic epilepsy. |
Vitamin D Toxicosis:
| Although excess calcium intake is not thought to cause clinical problems in most cases, excess vitamin D3 can cause harmful calcium accumulation in tissues such as the kidneys. Supplements should be used carefully, and excess vitamin D3 should not be administered to susceptible species (eg, macaws). |
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| Additional Nutritional Concerns: |
| In addition to the well documented nutritional deficiencies in the traditional diets designed for psittacines, described above, the following dietary concerns should also be noted: 1) the relative inability of birds to use the vitamin A in raw carrots due to a lack of cellulase; 2) the potential sensitivity of individual birds to dyes and preservatives that are added to some seed and pelleted foods; 3) the high incidence of hepatic lipidosis in sedentary captive birds consuming
primarily seed diets; 4) the occurrence of hepatic fibrosis and cirrhosis secondary to aflatoxicosis from improperly stored seed and pet-grade peanuts; 5) the difference between food provided by well-meaning owners for their birds to eat (table foods, formulated pelleted diet, vegetables, etc) and what the birds actually consume (seed); and 6) the low palatability of most vitamin and mineral supplements added to water, which are not only ineffectual, but can lead to decreased
water consumption and dehydration. |
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