How to Detect Mastitis in Cows Using CMT Test Kit

How to Detect Mastitis in Cows Using CMT Test Kit


Mastitis is an inflammation of the udder tissue that can be caused by bacterial, viral, or fungal infections. It is a prevalent disease in dairy cows worldwide and can have a significant impact on milk production, cow health, and farm profitability. Detecting mastitis early is essential for effective treatment and preventing the spread of infection within the herd.

What is Mastitis in Cows?

Mastitis in cows refers to the inflammation and infection of the mammary glands or udder tissue. It can be caused by various bacteria, such as Staphylococcus aureus and Streptococcus agalactiae, which enter the udder through the teat canal. Other factors, including poor milking hygiene, inadequate teat disinfection, and environmental conditions, can contribute to mastitis development.

Mastitis can result in reduced milk yield, altered milk composition, and poor milk quality. Infected cows may exhibit symptoms such as swollen udders, changes in milk appearance, and decreased appetite. If left untreated, mastitis can lead to chronic infections, reduced reproductive performance, and even culling of affected cows.

Importance of Early Detection

Early detection of mastitis is crucial for several reasons. Firstly, it allows for prompt treatment, minimizing the severity of the infection and reducing the risk of complications. Secondly, early detection helps prevent the spread of mastitis-causing bacteria to other cows within the herd. Implementing effective control measures at an early stage can significantly reduce the economic losses associated with mastitis.

Overview of CMT Test Kit

The California Mastitis Test (CMT) is a widely used tool for mastitis detection in cows. The CMT test kit consists of a plastic paddle, which contains four compartments or test wells. The kit also includes a CMT reagent, which is a mixture of detergent, sodium carbonate, and a color indicator.

The CMT test kit is readily available and relatively affordable, making it accessible to dairy farmers of all sizes. It provides a simple and quick method for on-farm mastitis screening.

How does the CMT Test Kit Work?

The CMT test kit works based on the principle of detecting somatic cells in milk. Somatic cells are white blood cells and epithelial cells shed from the udder tissue in response to infection or inflammation. These cells increase in number when mastitis is present.

When the CMT reagent is added to a milk sample, it causes the somatic cells in the milk to clump together, forming a gel-like consistency. The degree of gel formation indicates the presence and severity of mastitis in the cow’s udder.

Step-by-Step Guide to Using the CMT Test Kit

To use the CMT test kit for mastitis detection, follow these steps:

  1. Preparing the CMT test kit: Ensure the test kit is clean and dry before use. Make sure to label each well of the paddle for accurate identification.
  2. Collecting milk samples: Collect milk samples from each quarter of the cow’s udder into separate containers. Ensure proper hygiene and cleanliness during the sampling process.
  3. Adding milk samples to the test wells: Pour a small amount of milk from each sample into the corresponding well on the CMT paddle, filling it up to the marked line.
  4. Observing the reaction and scoring: Gently rock the paddle back and forth for about 10 seconds to mix the milk with the CMT reagent. Observe the consistency and texture of the milk in each well.
  5. Interpreting the results: Based on the gel formation, score each well from 0 to 3, indicating the severity of mastitis in the corresponding quarter.

Interpreting CMT Test Results

The CMT test results are typically interpreted based on the following scoring system:

• Score 0: No gel formation, indicating no mastitis detected.
• Score 1: Slight gel formation, suggesting a mild infection.
• Score 2: Moderate gel formation, indicating a moderate infection.
• Score 3: Firm gel formation, indicating a severe infection.

The scores obtained for each quarter can help identify the presence and severity of mastitis. Cows with higher scores (2 or 3) may require immediate veterinary attention and appropriate treatment.

Benefits of Using CMT Test Kit for Mastitis Detection

The CMT test kit offers several advantages for mastitis detection in cows:

  1. Early detection and prompt treatment: The CMT test enables dairy farmers to identify mastitis at an early stage, allowing for timely treatment and management interventions.
  2. Cost-effective and efficient screening: The CMT test kit is relatively inexpensive and provides rapid results, making it a practical screening tool for large-scale dairy operations.
  3. Enhanced milk quality and cow health: By identifying and addressing mastitis cases promptly, dairy farmers can maintain better milk quality and safeguard the overall health and well-being of their cows.

Limitations and Precautions

While the CMT test is a valuable tool, it does have certain limitations and precautions to consider:

  1. Influence of cow and milk factors: Various factors, such as the stage of lactation, breed, and individual cow variations, can influence the test results. Additionally, certain milk abnormalities, such as high somatic cell counts unrelated to mastitis, may affect the accuracy of the test.
  2. Supplemental diagnostic tests: The CMT test provides an initial indication of mastitis presence, but confirmatory tests, such as bacterial culture and sensitivity testing, may be necessary to identify the specific bacteria causing the infection and determine the most appropriate treatment.
  3. Proper technique and hygiene: Accurate test results depend on using the CMT test kit correctly and ensuring proper hygiene during the collection and testing process. Follow the manufacturer’s instructions and maintain clean equipment to obtain reliable results.

Tips for Preventing Mastitis in Cows

While early detection is essential, preventing mastitis in cows is equally important. Here are some tips to minimize the risk of mastitis:

  1. Good management practices: Implement proper hygiene and sanitation measures, including clean bedding, regular udder washing, and disinfection routines.
  2. Teat care: Ensure proper teat preparation before milking, including teat dipping or spraying with approved disinfectants.
  3. Regular veterinary check-ups: Schedule regular visits from a veterinarian to assess the herd’s health, provide vaccinations, and perform routine mastitis screening.


Early detection of mastitis is crucial for maintaining the health and productivity of dairy cows. The CMT test kit provides a practical and cost-effective solution for mastitis detection, allowing dairy farmers to identify infected cows promptly and initiate appropriate treatment. By implementing the CMT test as part of their mastitis control program, farmers can minimize economic losses and ensure the well-being of their herd.


  1. Can the CMT test be used for other animals besides cows? The CMT test is primarily designed for cows and may not be suitable for other animal species. Consult with a veterinarian for mastitis detection methods appropriate for specific animals.
  2. How often should I test my cows using the CMT kit? Regular testing using the CMT kit is recommended, especially during the freshening period and before drying off. Consult with a veterinarian to determine the optimal testing frequency for your herd.
  3. Can the CMT test detect all types of mastitis-causing bacteria? The CMT test is effective in detecting mastitis caused by increased somatic cell counts, which is an indicator of inflammation or infection. Confirmatory tests may be necessary to identify the specific bacteria involved.
  4. What should I do if my cow tests positive for mastitis using the CMT test? If a cow tests positive for mastitis using the CMT test, consult with a veterinarian for further evaluation and treatment options. Prompt and appropriate treatment is crucial for successful management of mastitis.
  5. Are there any alternative methods to the CMT test for mastitis detection? Yes, there are other diagnostic tests available, such as bacterial culture and somatic cell count analysis. These tests provide additional information about the specific bacteria causing the infection and the severity of the inflammation. Discuss with a veterinarian to determine the most suitable testing methods for your herd’s needs
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