Why measured hemoglobin is gaining ground over MCHC

Measured hemoglobin parameters are getting renewed attention in veterinary diagnostics, as clinicians and manufacturers alike push for CBC data that are more dependable at the point of care. The latest signal came in April 2026, when Zoetis said its Vetscan OptiCell analyzer would become the first point-of-care hematology system to offer CHCM, or cellular hemoglobin concentration mean, a parameter the company said had previously been limited to reference labs. Zoetis positioned CHCM as a direct optical measurement that can outperform calculated MCHC when anemia, hemolysis, or other endogenous interferents complicate interpretation. (news.zoetis.com)

The underlying debate has been building for years in veterinary clinical pathology. MCHC has long been part of the standard CBC, but it is a derived value rather than a directly measured one. In practice, that matters because any error or interference affecting the hemoglobin measurement, red blood cell count, or mean cell volume can distort the final MCHC. More recent veterinary discussions have focused on CHCM as a way to assess hemoglobin concentration at the level of individually analyzed erythrocytes, potentially offering a cleaner readout when calculated indices become unreliable. (pmc.ncbi.nlm.nih.gov)

That distinction is especially relevant in anemia workups. A 2025 canine study examining the gap between MCHC and CHCM found that increased differences were associated with interferences such as hemolysis and icterus, reinforcing the idea that elevated or discordant MCHC values may reflect sample problems rather than true erythrocyte biology. Educational and review sources aimed at veterinarians make a similar point: when CHCM and MCHC diverge, the discrepancy itself can be diagnostically useful because it may flag free hemoglobin or other artifacts affecting the sample. (pmc.ncbi.nlm.nih.gov)

There is also a broader instrumentation story here. Zoetis said the CHCM addition is part of a 2026 update to Vetscan OptiCell, alongside plateletcrit, bringing the analyzer to 24 reported parameters. The company said the goal is to move “reference lab level” insight closer to the exam room without changing the platform’s cartridge-based workflow. In the company announcement, Zoetis executives framed CHCM as a way to support clearer assessment of red blood cell abnormalities, while veterinary oncologist Dr. Sue Ettinger said reliable first-pass CBC data can help clinicians talk with pet parents and make decisions without waiting for outside confirmation. Those comments are company-supplied, but they reflect a real operational pressure in practice: speed only helps if the result is credible. (news.zoetis.com)

Independent literature supports the caution around calculated hemoglobin-related indices. Earlier comparative work in dogs, cats, and horses showed that hemoglobin measurement methods can introduce meaningful bias, which then affects calculated parameters downstream. More recent reviews in both veterinary and human hematology have likewise emphasized that MCHC is often best treated as both a biologic parameter and an analytical quality check, particularly when results appear unexpectedly high. In other words, the problem is not that MCHC is obsolete, but that clinicians need to know when it is signaling artifact instead of disease. (pubmed.ncbi.nlm.nih.gov)

Why it matters: For veterinary professionals, CHCM’s rise speaks to a familiar challenge: distinguishing true patient change from analyzer noise, especially in sick, fragile, or poorly sampled patients. In-clinic teams dealing with anemia, hemolysis, lipemia, or difficult collections often have to decide quickly whether to trust a CBC, repeat it, review a smear, or send the sample to a reference lab. A directly measured red cell hemoglobin parameter could improve confidence in those decisions, particularly if future studies show it changes triage, transfusion planning, anemia classification, or follow-up testing in a measurable way. It may also strengthen conversations with pet parents by giving teams a more defensible basis for same-visit recommendations. (news.zoetis.com)

There are still limits to the current evidence base. Much of the momentum around CHCM in practice is being driven by analyzer-specific literature, educational reviews, and manufacturer messaging rather than large prospective outcome studies across primary care settings. That means veterinary teams should treat CHCM as a promising interpretive tool, not a standalone answer. Blood smear review, clinical context, and an understanding of platform-specific performance still matter. (news.zoetis.com)

What to watch: The next phase will be whether CHCM remains mostly a differentiating feature for premium analyzers, or becomes a standard expectation in companion animal hematology. Watch for additional validation studies, conference presentations, and real-world reports showing whether measured hemoglobin parameters improve diagnostic accuracy, reduce send-outs, or alter anemia management in general practice, emergency, and specialty care. Zoetis has said the new CHCM and plateletcrit parameters are expected to become available to Vetscan OptiCell users in 2026, which should give the market an early test of how much demand exists for this level of CBC detail in-clinic. (news.zoetis.com)