How to Use the California Mastitis Test for Goats
In this post, I will cover how to use the California Mastitis Test (CMT) for Goats and how to read and interpret the results. Mastitis is a common problem among dairy goats. It is inflammation of the udder tissue that can be caused by bacterial infections or trauma to the udder. Mastitis can cause discomfort for the goat, reduce milk production, and even lead to the culling of the affected animal if left untreated. To read a more in-depth blog on mastitis and how you can prevent it in your herd, check out my post What is Mastitis in Goats.
To identify mastitis in your goats, you can use the California Mastitis Test (CMT). This simple and affordable test can be performed by homesteaders, without the need for expensive laboratory equipment.
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I am not a veterinarian, this is only an example of what we do with our animals. Please consult your vet before making any health decisions with your animals.
What is the California Mastitis Test (CMT)?
The California Mastitis Test (CMT) is a screening test used to detect mastitis in dairy animals, including goats. This test works by detecting changes in the milk's viscosity caused by the presence of somatic cells. These cells are from the immune system that are released when the udder is infected. The test is named after the University of California, where it was first developed in the 1970s.
How to perform the CMT on goats
You will need the following materials to perform the CMT on goats:
- CMT test kit at Jeffers.com (or)
- CMT concentrated reactant solution on Amazon
- CMT paddle
- Disposable gloves
- Warm soapy water
- Paper towels to dry the udder
The CMT kit used to be very difficult to find when we first started with goats. I was pleasantly surprised to see that most of the materials are now available on Amazon individually. If you've purchased the kit in the past and only need a refill of the solution (which was our case) then you can get the concentrate on Amazon. However, if you need the whole kit including the empty mixing bottle, or the paddle with the ring measurements you can get it at Jeffers.com
You also have the option to just buy the concentrated solution and mix up the whole gallon amount that the bottle makes. If you don't have the paddle you can use a small plastic cup and add equal amounts of milk and prepared solution to do the test. I feel like the kit is the easiest way.
How to prepare the California Mastitis Test
In the kit, you will get an empty bottle with two fill lines. Fill the bottle with the reactant solution concentrate to the first line on the bottle. Then fill the rest of the bottle with water until you reach the second line at the top. Then shake to mix.
Wash the paddle and be sure to rinse it well. Soap residue can cause a positive reaction. Dry well. Be sure to wash the paddle between testing different goats.
Here are the steps to perform the CMT on goats
1: Thoroughly wash the goat's udder and teat, and be sure to rinse and dry well. (See Our Goat Milking Routine to find out how I wash our goat's teats and udders.)
2: Wash your own hands or wear disposable gloves.
3: Then squirt a few discarded squirts from each teat as these can be contaminated with bacteria from the teat canal.
4: Squirt enough milk from each teat into the corresponding paddle well. The paddle comes with 4 wells to serve dairy cows. For a goat, you will only use 2. You can label them with a wax pencil to keep track of each side.
5: Then tip the paddle to pour out the milk until the milk line lines up with the larger, outer circle on the inside of the paddle well.
6: Then add enough reactant agent until the milk and reactant reach the inner, smaller circle in the paddle well when tilted. The milk and reactant should be in equal amounts.
7: Gently swirl the test cup to mix the milk and reagent.
8: Now observe the reaction of the milk and reagent mixture. If the milk remains liquid, the goat is not likely to have mastitis. If the mixture becomes thick or clotted, the goat may have mastitis.
How to interpret the results of the California Mastitis Test on goats?
The CMT test measures the level of somatic cells in the milk. So a higher level of somatic cells indicates that the goat's udder is inflamed and may have mastitis. The test results are usually graded on a scale of 0 to 4, with 0 indicating no mastitis and 4 indicating severe mastitis.
- 0 = Negative - no reaction or slight thickening
- 1 = Trace - slight thickening
- 2 = Weak positive - thickening that forms small flakes
- 3 = Positive - thickening that forms large flakes
- 4 = Strong positive - thickening that forms a gel or clot
If you get a positive result from the CMT test, it is important to begin steps to heal the udder. There are many different ways homesteaders treat mastitis in their goats. Such as natural remedies including massage, essential oil treatments, and frequent milking that can eliminate milder cases of mastitis. More acute cases may require a veterinarian's help, and if necessary, a milk sample sent to a lab and treatment with antibiotics. Early detection and treatment of mastitis can help prevent the spread of the infection and minimize the impact on the goat's health. Severe mastitis can result in udder amputation and even death of the goat, so if you have any questions please contact your vet.
Because of this, we have a procedure for treating our animals with supportive care and a product called ToDay which is an intermammary treatment for mastitis. It is available at feed stores or on Amazon. I cover our procedure in detail in my post on How to Treat Mastitis in Goats.
How to use the California Mastitis Test in a preventative health check for goats
It is a good idea, especially if you are new to dairy goats, to periodically test your goats for CMT. You should do this even if they aren't showing any signs of mastitis. This can help diagnose subclinical mastitis which shows little to no symptoms.
Other ways we do health checks are, by feeling the udder for warmth, hardness, or lumps daily when we milk. And using a strip cup to filter out any odd clumps in the milk.
How to use a strip cup to check for mastitis in goats
I also recommend that you invest in a strip cup, which is a small metal cup with a removable screen top. To use the strip cup you wash the udder, squeeze out a few discarded squirts of milk, then squeeze a test squirt through the screened cup. The screen will filter out any clumps in the milk. We do this daily in our milking routine. (link) If anything looks out of the ordinary, we test with the CMT.
Can I get a false reading using the CMT with goats?
Yes...ish. The CMT was originally designed for cows' milk, and because cows' milk is slightly different than goats you can get slightly different results. Cows milk tends to gel easier with the reactant. Whereas goats might have mastitis and the gel won't form quite as obviously.
There are other reasons why you may get a more positive gel. Consider the following:
-If the goat is tested 1-2 weeks following treatment then she may show a positive result.
-If the goat is early in milk (producing colostrum) or late (being dried off. These times tend to be stressful to the udder and may produce somatic cells.
-Teat injury
-Udder injury
-Periods of estrus
-Uterine infection
In conclusion, the California Mastitis Test is a simple and effective way for goat farmers to detect mastitis in their herd. By regularly testing your goats with the CMT, you can catch mastitis early and take the necessary steps to keep your goats healthy and productive.
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California Mastitis Test Concentrate Solution (CMT)
ToDay an intermammary treatment for mastitis
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