In-house cytology gets a practical refresh in vet dermatology: full analysis
A new peer-reviewed article in Today’s Veterinary Nurse offers a practical, step-by-step guide to in-house cytology in veterinary dermatology, underscoring how much of this work falls to veterinary nurses in day-to-day practice. The piece presents in-house cytology as a fast, cost-effective diagnostic tool for common skin and ear conditions, with an emphasis on proper sample collection, slide preparation, staining, and consistent documentation. (todaysveterinarynurse.com)
The article arrives at a time when dermatology teams are continuing to refine how they use in-clinic diagnostics to speed decision-making. Cytology has long been a staple of dermatology workups because it can quickly identify microorganisms and inflammatory patterns without waiting for outside laboratory turnaround. Merck Veterinary Manual describes cutaneous and auricular cytology as helpful for identifying bacterial, fungal, and possibly neoplastic disease, and recommends making at least 4 to 6 impression smears, with some retained for reference lab review when necessary. (merckvetmanual.com)
In the Today’s Veterinary Nurse article, the workflow covers lesion selection, collection methods, slide drying, staining, microscopic review, and communication of results. One notable detail is its handling of heat fixation. The article says otic or greasy samples may be heat-fixed “if desired,” but also cites a study showing no significant difference in yeast counts between heat-fixed and air-dried slides from dogs with confirmed Malassezia otitis externa, suggesting the step can be omitted without compromising diagnostic accuracy. That aligns with Merck’s more direct recommendation that heat fixing is no longer advised for skin cytology because it has not been shown to improve yeast visibility. (todaysveterinarynurse.com)
The broader literature also shows that sampling method can shape what clinicians see. A 2024 Veterinary Dermatology study, summarized by Clinician’s Brief in January 2025, compared plain glass direct impression smears with adhesive-slide impressions in canine superficial bacterial folliculitis. Plain glass slides yielded significantly more extracellular cocci and nuclear streaming, while adhesive slides captured more keratinocytes and miscellaneous debris. The takeaway from that review was practical rather than absolute: if bacteria detection is the main goal, plain glass may be preferable, but adhesive slides or acetate tape may help in difficult anatomic locations or when routine methods are not producing diagnostic samples. (cliniciansbrief.com)
That practical framing is likely to resonate with veterinary teams. The Today’s Veterinary Nurse article is written for support staff who are often responsible for the technical execution of dermatology diagnostics, and it reinforces that sample quality determines diagnostic value. Merck similarly stresses correct staining technique, access to oil immersion microscopy, and awareness of artifacts and limitations. In-house review can support a provisional diagnosis, but cytology still has boundaries, particularly when histopathology is needed to assess tissue architecture or tumor behavior. (todaysveterinarynurse.com)
Why it matters: For veterinary professionals, this is less about a brand-new diagnostic and more about operational discipline around one of the most useful tools already in the clinic. Better cytology technique can support same-visit treatment decisions, improve antimicrobial stewardship by distinguishing yeast from cocci or rods, and help teams monitor response over time. It may also reduce repeat visits driven by poor sample quality or inconclusive first-pass results. For nurses and technicians especially, the article reinforces their central role in dermatology workflow and in producing slides that are actually interpretable. (todaysveterinarynurse.com)
Expert and industry commentary around dermatology diagnostics points in the same direction: use the method that best matches the lesion and the clinical question. Merck advises direct slide impressions or clear acetate tape depending on the site, and specifically notes that tape prep should be stained before mounting rather than attached to the slide first. Clinician’s Brief adds that combining approaches may be useful when routine impressions are not yielding enough information. Together, those sources support a more tailored, protocol-driven approach rather than a one-technique-fits-all standard. (merckvetmanual.com)
What to watch: The next step is likely not a regulatory or commercial development, but wider adoption of standardized in-house cytology protocols, including clearer decisions on when to use glass, tape, or adhesive slides, when to skip heat fixation, and when to escalate from cytology to culture, biopsy, or referral. (todaysveterinarynurse.com)