Coliform Mastitis (E. Coli, Klebsiella sp., Pseudomonas sp., Serratia sp.) - An environmental bacterial infection of the udder

Where Do They Live?

Bedding, soil or water that is contaminated with manure.

How is Infection Spread?

From the environment to the udder at any time. The risk of new infection is highest around calving time.


About 70% of cases will be clinical at some time during the course of infection. Two thirds of cases last less than 10 days. Newly calved, older cows may have severe clinical (Awatery, toxic@) infections.


Clinical signs (changes in milk, udder or sick cow). Culture of milk samples collected at the beginning of clinical signs.


Reduced production, loss of milk discarded for treatment and antibiotic withdrawal time. Some infected cows become sick (fever, off feed).


Most mild infections self cure. Consult your veterinarian for a protocol for the treatment of severe cases. Antibiotic treatment does not shorten the duration of infection nor lessen the clinical signs.

Estimated Cure Rate:

No antibiotic efficacy for coliform mastitis has been demonstrated. Spontaneous cure rates for E. coli are high. Klebsiella sp. infections can become chronic. Cure rates for other types are variable.

Preventive Measures:

  • Milk only clean, dry teats.
  • Keep bedding clean and dry in lactating and dry cow environments.
  • Calve cows in a clean, dry box stall or on pasture.
  • Keep yards, pastures, and laneways dry.
  • Maintain equipment to reduce liner slips and keep teat ends.
  • Balance lactating and dry cow rations to meet NRC requirements.
  • Vaccination may reduce the severity of signs caused by E. coli infection.

For more information:
Toll Free: 1-877-424-1300
Author: Ann Godkin - Veterinary Scientist/OMAFRA; Doug Dulmage - Dairy Farmers of Ontario; Mark McDougall - Dairy Farmers of Ontario
Creation Date: 01 March 1998
Last Reviewed: 01 March 1998