We know how important it is to catch changes in our companions' behaviors and habits as early as possible to address any potential disease before it becomes untreatable. But it's more difficult to spot problems in some species — and birds are among the most difficult.

Birds are essentially wild creatures that have been adapted to captivity and still possess many wild traits. One is their tendency to hide symptoms in the face of illness. This is an adaptation to living in a group. When a bird shows symptoms of disease, they are targets for predators and attract attention to their flock. The flock will reject them in order to avoid unwanted attention. Unfortunately, this same behavior continues in captivity and can make it difficult for caretakers to spot problems.

Kiwi is an 11-year-old sulfur crested cockatoo living with Mandy in her apartment. She is fed a diet of "parrot mix" as well as fruit and vegetables of varying types. She spends a lot of time out of her cage and is tightly bonded to Mandy.

Over the past few months, Mandy reports that Kiwi has been drinking more water and her droppings have changed color from a deep emerald green to a more bright "electric" green. She has not shown any other changes, but Mandy has noticed that the papers in the bottom of her cage seem to be wetter than they had been in the past.

There is without question a problem with Kiwi. The change in droppings color indicates a possible liver problem. When the liver in some types of birds is not functioning properly, a chemical change in the makeup of the droppings, as processed by the liver, causes the change in color.

The increased thirst and what sounds like increase in production from the urinary tact also can be caused by liver disease, although there are many diseases that also can lead to these symptoms.

The product of the urinary tract in birds is different than in mammals. Mammals produce urea, which is a liquid, while birds produce a solid material, yellowish to white in color, called uric acid. It is surrounded by liquid, mostly water, and then excreted. When birds drink excessively, as is the case with Kiwi, they will excrete excessive amounts of water from their urinary tract.

Kiwi needs diagnostic testing, including a blood and urine analysis. Again, the earlier the cause is discovered, the more likely we will be able to help Kiwi. Right now, we do not know definitively how long Kiwi has been dealing with the disease.

If indeed Kiwi is dealing with liver disease, I would consider diet as a possible cause. Seed-based diets in our psittacine patients are a long-term recipe for disaster. This is due to several factors. Seed-based diets allow birds to pick and choose what seeds they like to eat and leave those they don't, leaving the diet unbalanced. Frankly, even if a bird eats all the seeds in a mix, the diet still would be unbalanced. Another problem is that seed-based diets are high in fat. This fat can deposit in the liver and, over time, lead to death from liver failure. Kiwi is a candidate for this scenario.

If indeed Kiwi's blood work shows a liver problem, I would recommend an endoscopic exam and biopsy of her liver. This will help determine the type of liver problem and to what degree it has progressed. You then can formulate a treatment plan to hopefully turn her around with a dietary change.

Kiwi and all psittacine birds should eat a varied diet, which can be inconvenient for some caretakers. A pellet-base diet can provide complete nutrition.

Dr. Jeff Kahler is a veterinarian in Modesto, Calif.