Susan L. Clubb, DVM
Rainforest Clinic for Birds and Exotics, Inc., Loxahatchee, FL, USA
OVERVIEW OF ISSUE
Psittacine nutrition has made tremendous advances since the 1970's when formulated diets were first introduced. The 1980's and 1990's showed additional advancement in nutrition as numerous companies developed formulated diets that provided "complete" nutrition in each bite. While many pet bird owners and breeders jumped on the bandwagon and provided their birds with these diets, many others preferred the "more natural" approach of seeds and other foods, often offered from the table.
Today many bird owners and breeders prefer use a combination of formulated and natural diets. This approach can have benefits and pitfalls.
OBJECTIVES OF THE PRESENTATION
- Delineate important aspects of dealing with nutrition in a clinical setting.
- Present how nutritional counseling can be an important adjunct to clinical avian practice.
- Outline the most common nutritional deficiencies seen in avian practice.
- Detail specific nutritional challenges for various types of psittacine birds.
- Discuss supplementation of formulated diets with natural foods.
Nutritional Deficiency Diseases Often Seen in Clinical Practice
Deficiency diseases were one of the most common presenting problems for the avian practitioners in the 70's and 80's and can still be seen frequently, especially in older birds kept for years on unsupplemented seed diets.
Hypovitaminosis A is probably the most common nutritional deficiency that is routinely diagnosed in pet birds. The classic form with swelling of the oral papillae can be seen on routine physical exam. But hypovitaminosis A is also an important predisposing factor in the formation of abscesses in the nares, rhinolith, as well as sublingual abscesses.
B vitamin deficiencies are frequently seen in birds that are clinically anemic. Many of these birds respond very favorably to the supplementation to B-complex. Anemia is a common sequealae of almost any illness in pet birds because of the shot life span of avian red blood cells. Supplementation of B complex is very beneficial as an adjunctive therapy in treating virtually any chronic illness in birds. Iron supplementation should always be administered with great care due to the risk of excessive iron storage.
Another common complaint that will typically respond to B complex supplementation is weakness in the feet. Clients will often complain their bird falling off the perch. Supplementation will often be curative in a short period of time.
Low blood protein may be associated with malnutrition or disease states resulting in protein loss. Protein supplementation can be easily accomplished with the use of powdered protein supplements frequently utilized by athletes. Either egg protein or soy protein supplements can be used and are available in fruit flavors that are readily accepted by birds.
Calcium/ vitamin D deficiency. Calcium deficiency is typically not diagnosed by blood chemistry panels until it is critical. Radiography is often more useful although it is a subjective diagnosis as bone density scanning and measurement is not a frequent practice in avian medicine. Some clinical syndromes, such as egg binding may be a reflection of calcium deficiency. Hypocalcemic seizures are infrequently diagnosed if birds have exposure to sunlight such as birds living in southern climates. Full spectrum lighting is advised for birds living indoors at all times or birds in northern climates. I prefer calcium, magnesium citrate for calcium supplementation.
Phosphorus excess may result when excessive calcium is supplemented in the absence of phosphorus supplementation. Conversely Calcium diphosphate may not adequately correct calcium deficiency as the Ca:P ratio may not be sufficient to correct an overall phosphorus imbalance in birds eating an unsupplemented seed and or fruit diet. Because of oxalic acid in dark greens and cruciferous vegetables, calcium, although present may be unavailable. In addition excessive reliance on these greens and vegetables my result in oxalate precipitation in kidneys and resultant kidney disease.
The use of formulated diets has certainly made dietary management of pet birds easier for the clinician. And many clinicians, especially if they have limited clinical experience with pet birds, rely on dietary change to a formulated diet as an answer to disease processes that they cannot diagnose or understand. Clients are often recalcitrant to accept such a solution if they feel their initial complaint is not sufficiently addressed. While many will make the attempt to convert their birds to the recommended diet, a very large majority will not. Therefore an understanding of how people feed their birds and how a varied diet can be used with success is important to a successful avian practice. In my experience, most owners prefer to feed some variety rather than exclusive feeding of formulated diets.
Fruits and vegetables are an important part of any bird's diet. Even those birds eating primarily a high quality formulated diet will benefit from fresh, preferably raw vegetables and fresh fruits.
Preferred vegetables include green beans, a variety of peas, carrots, corn, broccoli and other cruciferous vegetables, celery, dark green leafy vegetables, etc.
Birds relish fruits, but quantities should be limited so they are not consumed to the exclusion of dietary items that are good protein sources. Remind owners that the commercially produced fruits that are produced to meet human tastes are very high in moisture and fruit sugars and dissimilar to the wild fruits consumed by parrots in their native habitat.
Nuts and high fat seeds are the favorite foods of many parrot species, and if allowed they will frequently consume these food to the exclusion of other dietary items. In addition, because of the caloric density of these foods, they don't consume as much as they would need to with other foods. So they sift thru the food bowl looking for those items while throwing other food items aside. Clients often become frustrated with this behavior, thinking the bird is not eating enough, and then provide additional bowls of food which the bird in turn throws out of the cage resulting in waste and mess in the home.
Special Dietary Needs of Specific Psittacine Species
Budgerigars--American Budgies are "easy keepers" doing well on a mixture of small size formulated diet and small seeds such as white millet, and other similar sized seeds. English budgies however have a tendency toward obesity and high fat foods should be limited.
Cockatiels also do well on a mixture of seeds, some sunflower but significant millet and other small seeds and 50% small size formulated diet. Feeding an exclusive diet of formulated diets--in my experience--may be detrimental to the kidneys of cockatiels.
Quakers are a species that frequently have disease processes associated with a high fat diet. They should not be fed any high fat seeds such as sunflower, safflower, pumpkin seeds, nuts, etc.
Preferably their diet should consist of 50% small low fat seeds such as millet, 50% formulated diets with some fresh vegetables and fruit.
Amazon Parrots have a tendency toward obesity. They should not be fed fatty seeds and nuts. Their diet should consist of primarily a formulated diet supplemented with fresh fruits and vegetables.
Cockatoos are very efficient in utilization of foods and don't require a high caloric diet. So they often "hold out" for their favorite foods resulting in owners feeling they don't eat enough. In response the owner will then typically overfeed to entice the cockatoo to eat. The cockatoo then delights in throwing food all over the room. Cockatoos should be feed a formulated diet supplemented with fresh fruits and vegetables. As they typically eat "at the table" with their owners, owners should be coached on having healthy foods available for their cockatoos.
Macaw eat diets very high in fat in the wild. While typically macaw owners feed ample high fat foods such as high fat seeds and nuts, like other species they will typically fare better with a formulated diet, supplemented with fresh fruits and vegetables and a limited quantity of nuts.
In general I recommend supplementation of food rather than water. The addition of vitamins to drinking water can result in bacterial overgrowth, break down of the vitamins and dilution which actually results in limited benefit to the bird.
While formulated diets provide an easy way to provide complete nutrition in every bite, the exclusive feeding of formulated diets is often rejected by owners. The addition of natural foods can be an important form of enrichment. Supplements can be a useful and profitable adjunct to clinical practice. The practitioner should offer supplements of vitamins, calcium, protein, and fatty acids, as indicated by clinical signs, nutritional status, etc.
Susan L. Clubb, DVM 2009
Rainforest Clinic for Birds & Exotics Loxahatchee, FL, United States