Obesity is a common finding in pet birds. When body weight exceeds the normal or expected body weight for that species by 15% or more, a bird can be considered obese. This condition is hazardous to the bird’s health due to increased risks of heart disease (in the longer lived parrots), lipoma formation, and egg binding in reproductively active hens, exercise intolerance and respiratory distress upon excitation or stress, and increased anesthetic and surgical risks. In addition to these health risks, breeding success can be decreased due to infertility.

Clinical Signs

Before the bird is even handled, obesity may be seen as bald patches in certain areas where the feather tracts have separated due to large deposits of subcutaneous fat. The bird may have a wide stance, with legs spread further apart than a normal bird. There may be a roll of fat, a “double chin” visible under the lower mandible.
Upon physical examination excess fat deposits are most likely to be found in the abdomen, manifesting as a distended, doughy abdomen, subcutaneously along the flanks and inner thighs, and around the clavicular area. Moistening the feathers and skin with alcohol in these areas will reveal white or yellow subcutaneous deposits of fat. Lipomas may be distinguished from a subcutaneous fat depot by their more circumscribed growth pattern.

Causes

At the most basic level, obesity is caused by an energy intake that exceeds energy expenditure over a period of time. This situation is most likely to occur in pet birds with limited exercise and high calorie and fat diets. Birds that are fed predominantly oil seeds or nut diets, such as sunflower seeds, peanuts, walnuts, are often prone to obesity. Frequently the owners feed the bird high-energy human foods such as cheeses, meat, whole milk, cookies, and cake. Boredom may also predispose a bird to obesity. The bird may just sit at the food dish all day, eating. Pet birds are often likely to get little exercise, being confined in cages for most of the day and wing trimmed to prevent flight.

Treatment

The most effective way to treat the obesity is to increase exercise and decrease calorie intake at the same time. Advise the owner to place the food and water at opposite ends of the cage, especially with one high and one low, forcing the bird to move about the cage more. The client should be advised to make sure the bird finds the new locations for the food and water and is still eating and drinking. If boredom is a problem, adding toys to the cage or increasing attention to the bird may be a solution. Offering a measured amount of food, changing the diet to reduce the calorie content, and decreasing the amount of fat in the diet can regulate calorie intake.
If the bird is being fed a relatively healthy basic diet but high fat or high calorie treats are the main problem, have the owner switch to low fat treats such as fruits and vegetables. That may be sufficient to achieve weight loss. Usually a more stringent feed restriction or diet change will be required. Feed restriction will probably not be the most satisfactory method because it does not satisfy the bird’s hunger and a vitamin or mineral deficiency could occur. Changing the diet to a temporary reducing diet followed by a permanent low fat diet is probably the most efficient and most satisfactory way to treat obesity. The bird must be closely monitored to assess the rate of weight loss and to assess whether any newly substituted diet is being consumed. High fat foods are highly palatable, so a bird used to fatty foods may be quite reluctant to eat low fat substitutes. The owner should be instructed to clean the bottom of the cage daily, using paper as a substrate so that the size and color of the droppings can be evaluated daily. Weight loss should not exceed three percent per week. If the owner is unable to weigh the bird weekly at home, weekly weigh-in appointments should be scheduled. If at all possible, the owner should house the obese bird individually during the weight reduction process. If more than one bird is in the cage or flight it will not be possible to tell which droppings came from which bird. Weight loss will become the only way to monitor the birds’ well being and food consumption. If a cage mate is already lean, it may create stress on the bird to be feed restricted or to be placed on a reducing diet. If lipomas are present simple weight reduction may result in resolution. If they are still present after normal weight is achieved, medical management or surgical removal should be initiated.

Dietary Management

If a temporary reducing diet is indicated for your patient the diet should be a low energy, low-fat, high fiber diet, such as Roudybush Formula AR. Birds used to consuming a large quantity of high-energy food will be unable to consume the same number of calories with such a diet offered free choice. Roudybush Formula AR has the same levels of protein, vitamins, and minerals as the maintenance diet, but the metabolizable energy is about 2650 kcal/kg compared to about 3250 kcal/kg in the maintenance diet. Formula AR is formulated to be the sole source of food for the bird, but small amounts of fresh fruits and vegetables can be given as treats.
If the bird is already eating pellets or crumbles as part of its diet, switching to Formula AR pellets or crumbles will pose little or no challenge. If the bird is on an all seed diet, it may not recognize the pellets as food. There are two methods of switching such a bird onto the diet. One method is to remove the old food and offer nothing but the pellets or crumbles. This should only be done with a bird that can be closely monitored by weighing twice weekly and observing droppings on a daily basis. If more than 5% body weight is lost, the bird should be put back on the old diet for 1–2 weeks before repeating the process.

The second method is to gradually introduce the pellets or crumble mixed in with the old diet. This is a slower but safer method, especially for owners who may not be able to closely monitor their birds.

Once the weight reduction has been achieved, switching the bird onto a maintenance pellet or crumble can be accomplished by simply substituting the reducing diet with the maintenance diet. After the bird is put back onto a maintenance diet it should be weighed every 2–3 weeks for 2–3 months to be sure that it is not regaining excessive weight. If the body weight is staying relatively constant, yearly check ups and weigh-ins should be sufficient follow up.
An important part of dietary management is owner compliance. Probably the most likely cause for weight reduction failure is owners who feel sorry for their bird, or owners who do not want to expend too much time or energy on the weight reduction process. The best ways to obtain good owner compliance is to simplify the process as much as possible and to impress upon the owner the hazards their obese bird faces. Providing a single reducing food item, such as Roudybush Formula AR, will help simplify the process for most owners. Most cases of avian obesity begin with a lack of knowledge and understanding by the owner.
Client education is the key to correcting and preventing this condition. When they are made aware of proper management and nutrition, owners can provide their birds with a greater opportunity to lead longer, healthier lives.