Gout is a common disease among humans, reptiles, and birds.
What causes gout?
Uric acid is one of the end breakdown products of dietary protein in birds and other animals. The uric acid is removed from the blood by the kidneys and excreted in the urine. Gout can occur if the level of uric acid in the blood exceeds the ability of the kidneys to remove it. In articular or synovial gout, the uric acid crystallizes in the joints, ligaments, and tendon sheaths. In visceral gout, uric acid deposits are found in the liver, spleen, pericardial sac (the covering of the heart), kidneys, and air sacs. When the uric acid crystallizes in tissues it forms small, white nodules called "tophi."
There are two types of gout. In primary gout, the high uric acid level is a result of an abnormal breakdown of protein. Primary gout is thought to be hereditary in humans. In secondary gout, the high level is due to the inability of the kidneys to adequately excrete the uric acid. In many cases, gout is secondary to kidney disease, but it can also be associated with medications, certain chronic diseases, overeating, improper diet (high protein, and possibly high Vitamin D or low Vitamin A), poor blood circulation, inactivity, decreased water intake or chronic dehydration, some infections, and other environmental factors which affect the kidneys' ability to eliminate uric acid.
What are the signs of gout and how is it diagnosed?
Joints may be enlarged, stiff, and painful, and the bird may continually shift weight from one foot to the other and have a shuffling gait. The bird may be unable to perch and so remains on the floor of the cage. If the wings are affected, the bird may be unable to fly. If other internal organs are involved, there may be a decrease in appetite, lethargy, weight loss, and abnormal droppings. The bird may show a change in temperament, or die suddenly.
After examining the bird and obtaining a thorough history of the diet, environment factors, availability of water, and previous health problems and treatments, the veterinarian will suspect gout. Radiographs and blood tests for uric acid help to substantiate the diagnosis; the identification of uric acid crystals in joint fluid, biopsies, or tophi confirms it.
How is gout treated?
Any underlying dietary or environmental cause will need to be remedied. Birds with gout will be placed on a low protein diet. Vitamin A may be given to birds who had received an improper diet. Proper hydration is necessary and fluids may need to be administered. Medications such as allopurinol or colchicine may be used, but the exact dosage and safety of these drugs in birds have not been determined. Most birds will need to be treated for life or the condition will quickly reappear if therapy is discontinued. If arthritis from gout is severe, it is possible to surgically remove the uric acid crystals from the joint. Often the damage to the joints or organs is irreversible.
Pain medications such as butorphanol may be given. Changes in the bird's cage such as moving the food and water dishes to easily accessible locations and increasing the diameter of the perches may be helpful.
The prognosis for a bird with gout is generally poor.