Mastitis Detection: A Practical Herd Checklist

Mastitis is easier and cheaper to manage when you find it early. This checklist is built for the milking parlor, the barn and the herd records.

Key points

Strip every quarter at every milking.
Note heat, swelling and teat end condition as well as the milk.
Severe cases make the whole cow sick and need a vet right away.
Use cell count trends to find cases you cannot see.
Keep written records and follow withdrawal times exactly.

What mastitis is and why detection matters

Mastitis is inflammation of the udder, usually caused by bacteria that enter through the teat end. A cow has four quarters, and each one can be infected on its own. Some cases are obvious. Many are not, and those quiet cases cost milk and spread to other cows.

A good detection routine does two things. It finds sick cows quickly so your vet can guide care, and it shows patterns that point to a problem in the milking routine, the bedding or the cow environment.

The checklist at every milking

Make the check part of the routine so it happens at every milking and not only when someone has time. The person doing the prep should be trained on what normal milk and a normal udder look like.

Strip each quarter into a strip cup or onto a dark surface before attaching the unit
Look for flakes, clots, watery milk or a change in color
Feel for heat, hardness or swelling in the quarter
Watch for a cow kicking or flinching during prep
Check that the teat end looks smooth, not rough or ringed
Note any cow that is milking out slower or faster than usual
Mark and separate cows with abnormal milk so their milk is handled as your vet advises

Reading the signs by severity

Mild cases show changes in the milk only: a few flakes or small clots, with the cow acting normal. Moderate cases add a hot, swollen quarter. Severe cases make the whole cow sick, with fever, no appetite, a down cow and sometimes shock.

A severe case is an emergency. Do not wait to see if it improves. Call your vet right away and get the cow comfortable, with water and a safe place to rest, until help arrives.

Finding the hidden cases

Cows without visible changes can still be infected. These subclinical cases show up in somatic cell count data from herd test day or from your milk buyer, and in tests such as the California Mastitis Test paddle if your vet recommends one.

Look at the trend for each cow over several tests rather than one result. A cow with high counts month after month is a different problem from a first-time rise. Your vet or milk quality adviser can help you set a cut point that suits your herd.

Keep records that you can use

Detection is only useful if cases are written down. Record the cow, the quarter, the date, the signs, who found it, what the vet advised and the date she may return to the tank. Over time these records show which cows repeat, which season is worst and which fresh heifers struggle.

Ask your vet about culturing milk from clinical cases. Knowing which bacteria are involved helps decide what to change in the herd.

Cow ID, quarter and date
Severity and signs observed
Whether a culture was taken and the result
Treatment plan from the vet and withdrawal end date
Outcome: recovered, repeated or culled

Training your crew and working with your vet

A checklist only works if every person on the shift uses it the same way. Walk new employees through a normal udder and normal milk, then have them strip a few cows beside an experienced milker. Repeat the training when you change protocols, and make it available in the languages your crew speaks.

Post a simple card near the parlor that shows what to do when abnormal milk is found: mark the cow, note the quarter and tell the person in charge. Short, clear steps are followed more often than long ones.

Bring your records to a herd health visit and ask for a written mastitis plan. A good plan covers which cases to culture, how to judge severity, when to call right away and how treated cows are marked and milked.

Which cases should we culture, and where do samples go?
How do we judge mild, moderate and severe cases?
What cell count level should trigger a recheck in our herd?
How should we handle cows that keep coming back?
What is our written withdrawal plan?

Common mistakes

The biggest mistake is skipping the strip when the parlor is rushed. Others include using dirty hands or towels, letting a treated cow's milk enter the tank, and treating every case the same without a diagnosis.

Any treated cow's milk must stay out of the tank for the withdrawal time on the label or the time your vet gives you. Follow it exactly, and make sure every milker knows who is on the treated list.

When to get help: Call your veterinarian for any cow that is sick, off feed or has a hard, hot quarter, and ask about milk culture for repeat cases. Your milk buyer or milk quality adviser can help interpret cell count reports.

Sources and further reading

Organization homepages are linked so you can search them for current guidance on this topic.

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