Study validates stall-side IgG assay for foal passive transfer checks

A new study in Equine Veterinary Journal validates a stall-side lateral-flow immunoglobulin G (IgG) test, called Sidekick, for rapid measurement of foal IgG levels during neonatal management. The authors compared the point-of-care assay with radial immunodiffusion and immunoturbidimetric testing, both established laboratory methods, and found strong agreement with the reference methods, along with high repeatability across the clinically relevant 4–8 g/L range. The paper was published online April 28, 2026, and the researchers said the assay could support faster decisions when evaluating foals for failure of passive transfer. (pure.ulster.ac.uk)

Why it matters: For equine veterinarians, the appeal is speed without giving up too much confidence in the result. Failure of passive transfer can leave foals vulnerable to infection and sepsis, and common clinical cutoffs still guide treatment decisions: less than 200 mg/dL is considered failure, 200–800 mg/dL partial failure, and more than 800 mg/dL adequate transfer in many clinical references. A stall-side test that tracks well with lab methods could shorten the window between sampling and intervention, especially in ambulatory or farm settings where shipping delays can slow plasma or colostrum decisions. The main caveat is that this validation was based on a small cohort of 10 foals. (pure.ulster.ac.uk)

What to watch: Watch for larger field studies, broader independent validation, and whether practices begin folding quantitative stall-side IgG testing into routine foal screening protocols. (pure.ulster.ac.uk)