The Gram Stain

                        --------------



Another effective tool available to the avian veterinarian is the

Gram stain.  Various specimens (feces, discharges, pus, etc.)

from the patient can be Gram stained and examined

microscopically.  Such a preparation yields a surprisingly large

amount of information:  whether or not bacteria and yeasts are

present in the sample; the relative numbers of organisms

present; their shape and relative size; and their Gram stain

reaction (Gram-negative bacteria appear light red or pink and are

generally considered the major disease-causing bacteria among

caged birds; Gram-positive bacteria appear dark blue or violet

and make up most of the normal gastrointestinal and respiratory

tract microflora of caged birds).  Just knowing this information

aids in the tentative identification of the bacteria present.  An

actual culture would be necessary to make a positive

identification.  The advantage of the Gram stain is that it

represents a relatively inexpensive method of determining the

microbiologic status of a patient.  More important, it provides

a convenient method for monitoring a patient's progress during

and after antibiotic therapy.