Parakeets suffering unusual droppings or vomiting may have gastrointestinal problems. One clear sign of problems is dirty vent feathers, stained or clogged by diarrhea. Check Charlie underneath daily, as clogging is a serious problem, and take him to the vet if he's ill for more than 24 hours.
Bacterial infections cause most upset tummies in parakeets. Green, mucusy, bubbly, sticky or scanty droppings are signs of bacterial infection. Vomiting is another symptom, though sometimes birds seem to vomit when they aren't actually ill. If they spit up fairly solid food from their crops, they're regurgitating, which is normal and even healthy behavior. True vomit is semi-digested food. Keep your parakeets warm, supply them water and offer a variety of foods to keep up energy supplies. Water open to contamination from droppings is a common source of infection, so use an inverted water dispenser. Vets prescribe antibiotics for bacterial infections.
Giardia, a tiny parasitic organism, causes chronic gastrointestinal problems. It is difficult for vets to diagnose and treat. A parakeet producing lots of pale droppings could have giardia. Another sign is feather-picking, especially under the wings and on the thighs, chest and abdomen. Giardia infections are more common in birds who have access to the ground, or who live or have lived in poor conditions. Vets use droppings to diagnose infections.
Vomiting and diarrhea are clear signs Charlie has an upset tummy, but sometimes the cause isn't clear. Diseases that affect other parts of his body, such as tumors or fatty liver disease, can cause diarrhea. Antibiotics are another possible cause, as they kill helpful as well as harmful bacteria. Birds are sensitive; perhaps moving him to another room or changing his diet has made him ill. Sometimes abnormalities of the gastrointestinal system develop as birds grow. Whatever the cause, a bird with gastrointestinal problems needs to see a vet.
Maintaining your budgie's health involves cleaning out his cage daily, removing old food and droppings, and using a water bottle instead of a bowl. A healthy diet -- including fresh fruit and vegetables, sprouted seeds, pellets, whole-wheat pasta and bread -- also helps keep his digestive system working well. Keep commercial parakeet food dry and sealed, as old, moldy seed can cause stomach problems. Worm your bird regularly to prevent infestation, and don't introduce him to birds that haven't spent three months in quarantine in another room.