It is useful to estimate the number of bacteria and general proportions of Gram positives to Gram negatives present on each slide. By determining an estimate of the number and types of bacteria present, the veterinarian can better determine if specific cultures or other tests, treatments, or management changes should be carried out. In general, most healthy psittacines have primarily Gram positive bacteria in their GI tract. Gram negative bacteria may be found in smaller numbers or percentages than Gram positive bacteria. Thus in a potentially sick bird, we are looking for increased numbers and proportions of Gram negative bacteria compared to Gram positive bacteria.
Yeasts are types of fungi.
The most common is Candida sp. Spores of this fungi are ubiquitous, however, they may become pathogenic in debilitated or immuno-suppressed individuals. Their presence and in what numbers and forms help determine if treatment is necessary. These all stain Gram positive and are up to four times larger than bacteria. Small numbers of single yeast cells are common in normal healthy psittacines.