New Diagnostic Tools Aim to Improve Detection of Canine Mast Cell Tumors
Mast cell tumors remain one of the most frequently diagnosed cancers in dogs—and one of the most challenging to identify early. Often appearing as ordinary skin masses, they can be difficult to distinguish from benign lesions without further testing, which can delay diagnosis and treatment decisions.
In January 2026, IDEXX Laboratories announced updates to its diagnostic offerings that are intended to address some of these challenges. The company plans to expand its IDEXX Cancer Dx Panel to include canine mast cell tumor detection and introduce fine needle aspirate (FNA) cytology capabilities on the IDEXX inVue Dx Cellular Analyzer.
Together, these additions are designed to support earlier assessment and faster decision-making in clinical practice, particularly for skin masses that may otherwise go undifferentiated.
Expansion of the Cancer Dx Panel
The IDEXX Cancer Dx Panel is currently used by thousands of veterinary practices, primarily for lymphoma screening. According to IDEXX, more than 5,500 clinics use the test, which has been shown to detect lymphoma prior to the onset of clinical signs in some patients.
Beginning in mid-2026, mast cell tumor detection will be added to the panel. IDEXX reports that the expansion will not change sample requirements or turnaround times, which typically range from two to three days. With the addition of mast cell tumor detection, the panel is expected to cover a larger proportion of common canine cancers.
In practice, the test may be used during routine wellness visits for at-risk dogs or when clinical findings raise suspicion for mast cell disease. The goal is to provide veterinarians with additional information that can help guide diagnostic and treatment decisions earlier in the process.
In-Clinic Cytology With inVue Dx
IDEXX is also introducing FNA cytology for mast cell tumors on the inVue Dx Cellular Analyzer. Unlike traditional cytology workflows that require slide preparation and external laboratory review, the inVue Dx system evaluates aspirates directly in the clinic using a slide-free format.
Results are available during the patient visit, allowing veterinarians to discuss findings with clients without delay. When additional interpretation is needed, cases can be submitted for remote review by an IDEXX pathologist.
IDEXX has indicated that mast cell tumor detection is the first application in a broader plan to expand the inVue Dx cytology menu over time.
Why Mast Cell Tumors Pose a Diagnostic Challenge
Mast cell tumors account for a significant percentage of canine skin cancers, but their behavior varies widely. Some are slow-growing and localized, while others are aggressive and metastatic. Externally, they often provide little indication of how they will behave biologically.
Currently, there is no single test that can reliably detect mast cell tumors throughout the body before they become clinically apparent. Diagnosis typically depends on cytology, histopathology, or a combination of diagnostic approaches once a mass is identified.
By pairing blood-based screening with point-of-care cytology, IDEXX’s approach aims to reduce uncertainty earlier in the diagnostic process and support more informed clinical discussions.
A Shift Toward Earlier Insight
Advances in veterinary diagnostics continue to emphasize earlier detection and faster access to clinically relevant information. For veterinary teams, this can translate into more timely conversations with clients and clearer pathways for follow-up testing or referral.
While no single test replaces clinical judgment or comprehensive diagnostics, tools that provide earlier insight may help veterinarians navigate complex cases with greater confidence.
As cancer diagnostics continue to evolve, the broader goal remains consistent: improving clarity, reducing delays, and supporting informed decision-making for veterinarians and the clients who rely on them.
