Avian Blood Differentials: Choosing the Right Stain for Avian White Blood Cells

Avian blood smears can be more difficult to interpret than mammalian blood smears because several cell types in the field are nucleated. In mammalian samples, red blood cells are typically non-nucleated, and platelets appear as small fragments. In avian samples, red blood cells are oval and nucleated, and thrombocytes are also nucleated cells. That difference changes how the slide looks under the microscope and can make cell separation more dependent on stain performance.

Avian Samples Create More Visual Overlap

The main challenge in avian hematology is that several cell types can share features that are not usually present together in a mammalian smear. Avian red blood cells have visible nuclei, and thrombocytes are true nucleated cells rather than platelet fragments. Because of this, thrombocytes can be confused with white blood cells if the stain does not provide enough contrast or if the smear is difficult to read.

White blood cell identification also requires attention to avian cell types. Birds have heterophils, which serve a role similar to mammalian neutrophils, and lymphocytes are commonly seen in avian blood. When these cells are being reviewed manually, clear staining helps the reviewer separate one population from another.

Stain Choice Should Match the Counting Method

Phloxine B and Natt-Herrick’s Solution can both be used in avian hematology; however, they support different workflows. Phloxine B (which stains white blood cells bright pink to red while red blood cells remain largely unstained) is often useful when the lab needs a straightforward manual cell count. That contrast can make counting more direct, especially for labs that need to evaluate white blood cells and thrombocytes without a more complex staining process.

Natt-Herrick’s Solution provides a broader view and works by staining red blood cells and white blood cells in different colors. This helps the reviewer evaluate multiple cell populations in the same preparation and can be useful for laboratories that work with avian samples more often.

Poor Contrast Can Change the Interpretation

When staining does not clearly separate cell types, the issue can move beyond slide appearance. A thrombocyte mistaken for a white blood cell can affect the count, and poor differentiation between heterophils and lymphocytes (as well as other cell populations) can make the differential less reliable, which could potentially affect the efficacy and accuracy of diagnosis and treatment.

In some avian samples, smear review may also support recognition of toxic heterophils or blood-borne parasites, both of which require clear visual detail.

Support for Avian Hematology Workflows

Avian blood work requires stains and procedures that match the sample and the purpose of the differential. Ethos Biosciences supports veterinary and diagnostic laboratories with hematology stains, reagents, and technical guidance for clearer, more consistent avian blood smear review.

If your lab is evaluating its avian hematology staining process, our team can help review your current workflow and identify the staining option that best fits your testing needs. Contact Ethos Biosciences to discuss staining options for avian blood differentials or to find the right product for your laboratory workflow.