California Mastitis Test
California Mastitis Test (CMT), a pivotal diagnostic tool in the realm of veterinary medicine. Designed to identify subclinical mastitis and gauge somatic cell counts, CMT plays a vital role in dairy herd health management.
The California Mastitis Test (CMT) stands as a prevalent diagnostic approach for detecting subclinical mastitis, serving as an indirect indicator of somatic cell counts (SCC) within milk.
Functioning at a qualitative level, the CMT delves into milk secretions, estimating DNA content with finesse. This estimation remains crucial due to the direct correlation between DNA concentration and the presence of white blood cells (WBCs) within milk. By deploying the CMT reagent, cellular lysis takes place, forming a DNA gel. The subsequent degree of gel formation serves as a quantitative proxy for WBC numbers within the milk sample.
Practical in its execution, the CMT procedure holds a pivotal role in identifying both clinical and subclinical mastitis. It stands as a widely adopted technique for estimating milk cellularity across bovine, ovine, and caprine species.
The approach involves depositing 2-3ml of milk into the CMT paddle, introducing an equal volume of reagent, and meticulously grading viscosity changes - ranging from negative to +3. Elevated viscosity values signify heightened cellular presence, potentially indicating escalated inflammation levels.
In the spectrum of bovine health, acute mastitis emerges as an orchestrator of milk abnormality, accompanied by pronounced heat, pain, mammary gland swelling, and systemic manifestations like fever and anorexia.
Species-specific dynamics unveil Mannheimia hemolytica as the chief instigator of acute mastitis in sheep, while goats contend with Staphylococcus epidemidis and coagulase-negative Staphylococcus species. Notably, Staphylococcus aureus and Streptococcus agalactiae claim prominence as the most frequent culprits in dairy cow mastitis cases.
References:
Erin Royster. Treatment of Mastitis in Cattle. Vet Clin Food Anim 31 (2015) 17-46.
Paolo Moroni. Rebhun’s Diseases of Diary Cattle. 3rd ed. Elsevier. 2018.
David E. Anderson. Sheep & Goat Medicine. Saunders. 2002.
Ronald L. Terra. Large Animal Internal Medicine. 6th ed. Elsevier. 2020.
Michigan State University Milk Quality and Mastitis Tests: CMT Fact Sheet
Merck Vet Manual: Mastitis in Cattle
