A transtracheal wash was performed on a 4-month-old boxer puppy with a history of chronic respiratory disease. The sample was very cellular, with a moderate amount of mucus. Degenerate and nondegenerate neutrophils were observed. Columnar epithelial cells, small lymphocytes, eosinophils, and macrophages were also seen. Some of the neutrophils contained pleomorphic coccoid organisms thought to be Mycoplasma species because of their small size and location. Special media were used, and Mycoplasma species and Escherichia coli were isolated (the latter was considered a contaminant). The patient was treated with enrofloxacin and amoxicillin-clavulanate and fully recovered. Mycoplasma species require special culture techniques and are typically cultured only if a special request is made; as a result, infection with these organisms may be underdiagnosed.

COMMENTARY: This is a good example of how cytology can aid in diagnosis and appropriate treatment for a patient. Recognition of possible Mycoplasma species in the transtracheal wash (TTW) led to a special request for culture. Although it is controversial whether Mycoplasma is a primary or secondary invader of the respiratory tract, it is generally believed that if these organisms are found in TTW samples, they are indicative of disease.

Transtracheal wash from a puppy with respiratory disease. Williams M, Olver C, Thrall MA. VET CLIN PATHOL 35: 471-473, 2006.