There is often a lot of talk about vitamins: vitamins added to seeds; vitamins in an extruded pelleted diet; vitamins that can be added to soft food or in the drinking water. But what are vitamins, anyway?
Vitamins are organic substances that are essential in minute quantities for the nutrition of most animals, including birds. They are present in natural foods and sometimes can be produced inside the body by vitamin precursors. Vitamins are involved in the regulation of many metabolic processes that go on inside the body, and can act as coenzymes and precursors of coenzymes, but they do not provide energy or serve as building units. Without vitamins, the body can? work properly. Deficiencies can cause such varied clinical signs as the inability to clot blood properly, form normal blood cells, grow normal bones or even cause infertility.
Technically called hypovitaminosis A, vitamin-A deficiency is one of the most common vitamin deficiencies in parrots that consume an all-seed diet. Seeds are low in vitamin A and calcium, and high in fat. Vitamin A is a fat-soluble vitamin. Like all fat-soluble vitamins, these can be toxic if overdosed.
Vitamin A is usually supplied in the precursor, beta-carotene, found in many dark green, leafy vegetables and also in red, yellow and orange fruits. Beta-carotene can also be supplied in a liquid capsule form available in most pharmacies. Because it is converted as needed to the active form of vitamin A, beta-carotene is safe and nontoxic, unlike vitamin A, which can be toxic if overdosed. I? a big fan of supplementing with beta-carotene for any bird suspicious for hypovitaminosis A.
Clinical signs of hypovitaminosis A can be many and varied. You might see swollen sinuses, swelling around the eyes, nasal discharge, increased urination, increased water consumption, trouble breathing or decreased appetite. Masses might be noted around the choana, larynx, under the tongue, between the mandibles, or the choana might be swollen and choanal papillae might be blunted or swollen. There might be white plaques in the oral cavity, or in the crop, the esophagus or the nares.
Hypovitaminosis A can also cause thickenings to the metatarsal and digital pads of the feet, predisposing a bird to pododermatitis. Scales from the bottoms of the feet can disappear, leaving the bottoms of the feet smooth and reddened.
Vitamin A is also necessary for proper vision. Deficiency of this important vitamin can result in many problems for the breeding hen and her mate.
Testing might show excess sheets of epithelial cells on a Gram? stain, or there might be yeast overgrowth associated with hypovitaminosis A. Infection with Candida albicans is a good sign that a bird may be suffering from vitamin A deficiency as the underlying cause for it.
Treatment involves ministering to any underlying infections, removing any affected tissue and providing the bird with an appropriate supplement. Commercial supplements are available, as are over-the-counter beta-carotene supplements. Your avian vet should assess the diet that your bird consumes for any apparent deficiencies so that this can be corrected.
Excerpt from BIRD TALK Magazine, September 2010 issue, with permission from its publisher, I-5 Publishing.
Want to learn more about vitamin deficiency in birds?