Regardless of the initial cause of illness or injury, neonatal psittacine birds often develop secondary bacterial and/or fungal infections that can become serious primary problems. These infections are most commonly encountered within the gastrointestinal tract. Often, the stabilization of the critical patient precedes the pursuit of an etiological diagnosis; however, bacterial and/or fungal culture and sensitivity testing from gastrointestinal samples is essential to guide antimicrobial therapy.
Cytology and Culture
Collect samples such as crop swabs prior to initiating empirical antimicrobial therapy. Bacterial and/or fungal culture and sensitivity testing from gastrointestinal samples is also essential to guide antimicrobial therapy. If the client has financial constraints, at least perform fecal and/or crop swab Gram stain cytology to assess the status of gastrointestinal microbial flora.
Blood can easily be collected from the right jugular vein (Fig 1). As in adults, a blood sample equivalent to 1% of the body weight can be collected from a healthy bird. Similarly to mammals, complete blood count and plasma biochemistry results in juveniles vary from those of adults. Young birds have a lower hematocrit due to a lower red blood cell count. They also have decreased total protein, albumin, sodium, chloride, calcium, and uric acid values as compared to adults. The potassium, phosphorus, alkaline phosphatase, and creatinine kinase values of the chick are higher than adults.
Survey radiographs normally show an enlarged crop, proventriculus and ventriculus. The intestinal tract is usually fluid-filled and may appear enlarged. The liver and heart are also relatively large. The air sac spaces are usually smaller than in adults.
Endoscopic examination can be a valuable diagnostic tool, however, the chicks should be fasted for a few hours (depending on age) to decrease the volume of the gastrointestinal tract. This will allow easier visualization of the coelomic cavity.
When presented with a clinically ill juvenile bird, there are a host of diagnostic tests that can be performed to identify the underlying cause of disease and formulate a therapeutic plan just as in adult birds. When appropriate, obtain a minimum database including complete blood count, biochemistry panel, and survey radiographs. Additional testing may include cytology, culture, and laparoscopy.