Proventricular Dilatation Disease (PDD)

Proventricular Dilatation Disease (PDD) is one of the most confounding avian disorders. The disease affects the nerves that supply the bird's gastrointestinal tract, though it can also affect nerves that supply other organs, too.

PDD is also known as Macaw Wasting Syndrome and Parrot Wasting Syndrome because it's most commonly diagnosed in Macaws, African grey parrots, Amazon parrots, cockatoos, and conures.

Symptoms of PDD include weight loss, vomiting, changes in the bird's droppings, and a swollen crop, which is the muscular pouch near the throat. However, no one sign or symptom can distinguish PPD. Some birds may not show any signs of illness until they are very sick with the disease.​

Treatment will often be nonsteroidal anti-inflammatory drugs (NSAIDs), and the bird may have to be put on a special diet. However, there's no cure for the disease, so these treatments are just to reduce pain for the rest of the birds' lives.

Psittacosis (Parrot Fever)

Psittacosis, or "Parrot Fever," is a form of the Chlamydia bacterium that can affect all hookbills. The disease is highly contagious and can be passed from birds to other animals, as well as humans.

Symptoms of Psittacosis aren't specific, but they include difficulty in breathing, nasal and eye discharge, inappetence, and loose, watery droppings with general lethargy. Treatment is most often an antibiotic, tetracycline, which can be given orally or through injections. However, birds taking tetracycline cannot have calcium because of its effect on the medication.

Psittacine Beak and Feather Disease (PBFD)

PBFD is a serious illness that can affect all members of the parrot family and has been referred to as "bird AIDS," given the similarity between the diseases. Although most affected birds are under the age of two years, PBFD can affect birds of any age.

Symptoms of PBFD include feather loss, abnormal feather development, the absence of powder down (dander), and growths, lesions, and abnormalities of the beak. If a bird is showing symptoms, the veterinarian may do a skin and/or feather biopsy.​

Currently, there is no treatment for PBFD, so a vet will recommend supportive care that includes pain management.

Polyomavirus

Polyomavirus is a disorder that affects caged birds, particularly parrots. Birds that are newborn or juveniles are most at risk, and the disease is usually fatal.

Symptoms of polyomavirus include appetite loss, an enlarged abdomen, paralysis, and diarrhea. Some birds may not show outward symptoms at all, but are carriers of the virus and may shed it in times of stress, posing a risk of infection to other birds in the home.

There is no known treatment for polyomavirus. This disease can progress quickly and has a high mortality rate. If your bird is at high risk of exposure, aka they are exposed to many other birds, vaccination is available to help reduce the risk of illness.

Candida

Candida, or Candidiasis, is a fungal infection that can affect the digestive tract of all species of birds. The disease involves an overgrowth of yeasts that are normally found in a bird's digestive system.

Common symptoms of Candida infections include white lesions in and around the mouth and throat, vomiting, appetite loss, and a crop that is slow to empty. The bird might appear to be lethargic.

Most Candida infections are successfully treated using antifungal medications. Candida often develops secondary to another disease, so the bird should be examined and treated for all potential problems by a vet.