Nutritional Diseases in Birds

Nutritional Diseases in Birds

Obesity:

Birds have an inherent ability to fulfill their nutritional needs. Certain essential amino acids, vitamins, minerals, protein and energy amounts must be met each day. Because of the nutritional imbalances in seed, a bird eats more to satisfy its needs. Due to the high fat concentration and birds’ excellent ability to metabolize and absorb fats, this can easily lead to obesity.

Predisposing factors to obesity:

  1. Breed – cockatiels, budgies, cockatoos, amazons, canaries.
  2. Older birds and females in early breeding season.
  3. Decreased exercise, wing clipping, small cages, low social stimulation.
  4. Metabolic disease (pancreas and thyroid), and diabetes.
  5. Depoprovera injections.

Hypovitaminosis A:

Usually this disease is associated with high seed diets. I see it often in birds that are offered a good variety of foods. Psitticines have a high vitamin A requirement. A deficiency leads to disfunction of the gastrointestinal and mucosal epithelium. This is most commonly manifested in upper respiratory infection, oral abscesses, and sinusitis due to a disease process known as “Squamous Metaplasia”.

Hypocalcemia:

Low blood calcium may result in weakness, seizure-like activity and muscle spasms (most common in African Greys). It, combined with obesity, is the main cause of egg binding as well.

Metabolic Bone Disease:

This can be caused by an improper calcium:phosphorus ratio (as found in seed) as well as a diet low in calcium. Calcium is pulled from the bones to meet metabolic calcium needs.

Hypervitaminosis D:

This disease can result from a diet excess of vitamin D or from ingestion of rat poison containing Cholecalciferol. Excess vitamin D causes mineral deposition in the muscle and soft tissue. It is most common in hand fed baby birds which are given overdoses of vitamins in the formula.

Lysine Deficiency:

Low lysine levels (an amino acid) has been shown to cause poor feather color and may result in yellow plumage. It is sometimes seen in birds fed mainly corn.

Vitamin K Responsive Disorder:

This disease causes bleeding in birds that receive minimal amounts of dietary vitamin K. Most species can manufacture adequate amounts in their intestines. Conures seem to be affected most often and manifest signs of bleeding disorders, such as small hemorrhages in the beak, hemorrhages on the bottom of the feet and epistaxis (bloody discharge from the nostrils).

Vitamin E And Selenium Responsive Disorder:

Known as “White Muscle Disease” in other animals, Vitamin E and Selenium deficiency is most often seen in cockatiels. The disease causes paralysis of the legs which may be permanent.

Iron Storage Disease:

Though not common in psittacines, this condition causes severe liver disease in passerine birds like mynahs, toucans, and birds of paradise. It is prevented by feeding a diet with virtually no iron. Many dog foods are good for this purpose (such as Hills C/D diet).

Stress Bars:

Stress bars manifest as waves, bends, breaks and color lines in the feather vane. In nutritionally ill baby birds, every feather may have stress bars present. Stress bars may be produced from non-nutritional causes as well. Bacterial, fungal and viral infections can produce stress bars as will cold brooder temperatures, trauma and individual feather damage. Fortunately, these damaged feathers will moult and be replaced by normal healthy plumage provided the stress has been removed.

Food Preferences:

This varies dramatically when we bring a bird into a captive situation. Studies have shown that wild foods include flowers, buds, leaves, fruits, cambium, insects and regional seeds. Some psitticines consume parts of more than 80 species of grasses, shrubs and trees.

Birds have a tactile bill-tip organ, which helps them select and manipulate size, shape, texture, etc. Because of this organ and the habitual nature of birds, introducing new foods can be difficult. Seeds are very palatable due to their high fat content and they are familiar to the bird.

Studies have shown that when a pelleted diet is fed with fruit, vegetables and seed: seed consumption still prevails. This leads to inadequate and unbalanced nutrition. A study of reproductive success in 8 psittacine species conducted in Michigan showed an increase in fleging percentage from 62% to 83% when fed a pelleted diet + fruits + vegetables rather than seed + fruit + vegetables.

Converting A Bird To A Different Diet:

  1. Most birds in the wild would primarily feed twice daily (dawn and dusk). Return to this schedule. It increases owner/bird bonding, gives the bird a schedule/pattern, increases hunger and desire for food so the bird may accept new foods more readily. It also allows the food bowls to be washed completely twice daily to decrease bacterial growth.
  2. Feed the bird when you are eating. Most birds will want to eat if they see their owner eating

Pelleted Diet Conversion:

  1. Combine the seeds with pellets. Over a 2 week to 1 month period increase the amount of pellets and decrease the amount of seed.
  2. “Cold Turkey” – If a diet change to pellets is made suddenly and completely, the bird should be monitored very closely for eating and weight loss. Many birds will not eat for 2-3 days. They should not go for more than 2 days without eating or lose more than 10% of their body weight. If this occurs, the normal diet should be returned. Trying a variety of pellets may help the conversion.
  3. Seed-pellet cakes (commercially available) offer a transition food. When the new diet is accepted, replace the seed with pellets and wean off the seed-pellet cakes.
  4. When offering new vegetables, experiment with temperature and texture. Some birds prefer their vegetables steamed until soft and served warm. Smaller species enjoy theirs grated. Try “Bird Pizza” or “Bird Bread”.

Dietary Don’ts:

Chocolate, Coffee, Avocado, Lettuce, Sugar, Fatty Foods.

  1. Remember that variety is the spice of life – especially in food.
  2. Feed fruits and vegetables that are in season. They generally have the highest nutritional value at their natural time of year.
  3. Monitor what actually gets into your bird and experiment with textures to see what your bird prefers.
  4. Wash all fruits and vegetables thoroughly.
  5. Do not let soft foods sit more than 4-6 hours in the bowl.

Avian Nutrition Information