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© 1995, The Board of Regents of the University of Nebraska on behalf of the University of Nebraska–Lincoln Extension. All rights reserved.


Mastitis is a frustrating, costly, and complex infection. A good, workable, effective preventive control program is presented in this NebGuide.

Mastitis is an inflammation of the mammary gland usually caused by bacterial infection of udder tissues. Except for rare injuries, infectious bacteria or other pathogens, e.g. yeast, fungi, etc., enter the udder through the teat end. Mastitis in both clinical (obvious abnormality, visible to naked eye) and subclinical stages (unseen signs of abnormality, invisible to naked eye) is a frustrating, costly and complex disease that reduces the quality and quantity of milk.

Mastitis results from a complex interrelationship between the environment, the cow, and a host of bacterial or other pathogenic organisms. Mastitis severity is defined as clinical or subclinical in individual cases. The disease exists at different levels in all herds. The level can be measured by somatic cell count interpretation.

The benefits of a good mastitis control program are well documented. Failure to use an effective control program is costly. Losses include reduced milk production, elevated culling losses, added veterinary expense, milk discarded due to drug residues, and extra labor to handle or treat infected cows. Any dairy producer not using a good mastitis control program is either unaware of the losses being incurred -- or has chosen to ignore them!

The control program outlined herein, if carried out properly, will effectively minimize losses in most situations. However, there are a few types of udder infections that may require special diagnostic procedures and corrective measures.