ISSN 2398-2993      

Mastitis: Escherichia coli


Al Manning

Peter Down

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Synonym(s): E. coli


  • Cause: all strains of Escherichia coli.
  • Signs: clinical signs can vary from mild (clots in milk only) to severe (udder inflammation, pyrexia, systemic illness.
  • Diagnosis: positive culture from an aseptic milk sample. Often associated with no growths.
  • Treatment:
    • Mild cases often resolve without antibiotic treatment, but may benefit from NSAIDs.
    • Broad spectrum intramammary antibiotic tubes with NSAIDs.
    • Toxic presentation – NSAIDs, fluids, stripping out, +/- systemic antibiotics, +/- calcium.
  • Prognosis:
    • As with the presentation the prognosis varies from very good to guarded.
    • The toxic presentation is considered a veterinary emergency so treatment should be initiated as soon as possible.



  • E. coli Escherichia coli is a commensal gut pathogen in all animals.
  • Most strains are poorly adapted to survive for long periods in the udder as it is unable to adhere to and invade the mammary epithelium, but it is able to use lactose for energy. 
  • Severity of presentation is mainly influenced by cow factors, although not all strains of E. coli are pathogenic.
  • The toxic presentation is more likely to occur in early lactation (usually 1-3 days post-partum).
  • E. coli infections are often acquired during the dry period but only present during lactation.

Predisposing factors


  • Risk factors for environmental mastitis:
    • Calving into a dirty environment, contaminated with feces.
    • Overstocking: there is very little evidence on the ideal stocking rate for optimal udder health, below are some industry recommendations:
      • Open yard lying area: for animals over 700kg the minimum stocking density allowed by the RSPCA is 6.5m2 per cow. AHDB Dairy recommends 7.5m2 per cow, and the DairyCo Mastitis Control Plan recommends 1.25m2 per 1000 litres of production.(Correct 2017).
      • Cubicle: one cubicle per cow is the minimum stocking density allowed by the RSPCA, AHDB Dairy and DEFRA recommend at least 5% more cubicles than cows. (Correct 2017)
    • Lying down too soon after milking:
      • Inappropriate access to fresh feed (>60cm per cow) and water (>10cm per cow).
      • Lameness.
  • A low somatic cell count.
  • Negative Energy Balance (NEB) in the transition period can lead to immunocompromise, which predisposes to E. coli mastitis.
  • Antibiotic dry cow therapy in low cell count cows has been associated with an increased risk of E. coli mastitis in early lactation due to suppression of  “minor pathogens” Dry cow therapy: overview.
  • Severe acute E. coli mastitis can occur following dry-off with an internal teat sealant (and no antibiotic) where administration is contaminated with feces. 
  • Infection is often acquired during the dry period so close attention should be paid to the dry cow environment.


  • In all presentations E. coli proliferates rapidly, and dies quickly, releasing Lipopolysaccharide (LPS) endotoxin.
  • Recent evidence would suggest that LPS doesn’t cross into the blood, but the udder immune system can trigger a systemic response.
  • It has been suggested that the reason for the toxic presentation of E. coli mastitis is due to the stimulation of different inflammatory pathways, and the balance between TH1 and TH2 immune responses:
    • In the postpartum cow monocytes tend to stimulate a TH2 mediated response which downregulates the immune response.
    • In later lactation monocytes stimulate more TH1 cells developing a pro-inflammatory pathway which neutralises infection more quickly. 
  • It may be possible to predict susceptibility to mastitis based on pre-calving monocyte populations. One study demonstrated that cattle that went on to develop postpartum mastitis or metritis had higher concentrations of CD14+ monocytes two weeks before calving.


  • E. coli rarely persists for a long time in the udder, but udder adapted srtains do exist.
  • If infected during the dry period, clinical signs usually occur 2-3 days after calving.
  • If infected during lactation, clinical signs usually take 1-2 days to occur.


  • Toxic cases will shed a lot of bacteria and should be isolated.
  • E. coli is commonly classified as an environmental pathogen but it has been suggested that some strains are more adapted for udder survival.
  • Contagious spread of E. coli has been reported between quarters and cows.


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Further Reading


Refereed Papers

  • Recent references from PubMed and VetMedResource.
  • Ruiz R, Tedeschi L O & Sepúlveda A (2017) Investigation of the effect of pegbovigrastim on some periparturient immune disorders and performance in Mexican dairy herds. Journal of Dairy Science, 3305–3317 PubMed.
  • Pomeroy B, Sipka A, Hussen J, Eger M, Schukken Y & Schuberth H J (2017) Counts of bovine monocyte subsets prior to calving are predictive for postpartum occurrence of mastitis and metritis. Veterinary Research 48 (1), 13 PubMed.
  • McDougall S, Abbeloos E, Piepers S, Rao A S, Astiz S, van Werven T & Pérez-Villalobos N (2016) Addition of meloxicam to the treatment of clinical mastitis improves subsequent reproductive performance. Journal of Dairy Science 99 (3), 2026–2042 PubMed.
  • Persson Y, Katholm J, Landin H & Mörk M J (2015) Efficacy of enrofloxacin for the treatment of acute clinical mastitis caused by Escherichia coli in dairy cows. Veterinary Record 176 (26), 673 PubMed.
  • Bradley A J, Breen J E, Payne B, White V & Green M J (2015) An investigation of the efficacy of a polyvalent mastitis vaccine using different vaccination regimens under field conditions in the United Kingdom. Journal of Dairy Science, 98 (3), 1706–20 PubMed.
  • Hassfurther R L, Terhune T N & Canning P C (2015) Efficacy of polyethylene glycol-conjugated bovine granulocyte colony-stimulating factor for reducing the incidence of naturally occurring clinical mastitis in periparturient dairy cows and heifers. American Journal of Veterinary Research 76 (3), 231–238 PubMed.
  • Royster E, Godden S, Goulart D, Dahlke A, Rapnicki P & Timmerman J (2014) Evaluation of the Minnesota Easy Culture System II Bi-Plate and Tri-Plate for identification of common mastitis pathogens in milk. J Dairy Sci 97 (6), 3648–3659 PubMed.
  • Schukken Y H, Günther J, Fitzpatrick J, Fontaine M C, Goetze L, Holst O & Seyfert H M (2011) Host-response patterns of intramammary infections in dairy cows. Veterinary Immunology and Immunopathology 144 (3-4), 270–289 PubMed.
  • Keane O M, Budd K E, Flynn J & McCoy F (2013) Increased detection of mastitis pathogens by real-time PCR compared to bacterial culture. The Veterinary Record 173, 268 PubMed.
  • Cha E, Bar D, Hertl J a, Tauer L W, Bennett G, González R N & Gröhn Y T (2011) The cost and management of different types of clinical mastitis in dairy cows estimated by dynamic programming. Journal of Dairy Science 94 (9), 4476–4487 PubMed.
  • Lago A, Godden S M, Bey R, Ruegg P L & Leslie K (2011) The selective treatment of clinical mastitis based on on-farm culture results: I. Effects on antibiotic use, milk withholding time, and short-term clinical and bacteriological outcomes. Journal of Dairy Science PubMed.
  • Suojala L, Simojoki H, Mustonen K, Kaartinen L & Pyörälä S (2010) Efficacy of enrofloxacin in the treatment of naturally occurring acute clinical Escherichia coli mastitis. Journal of Dairy Science 93 (5), 1960–9 PubMed.
  • Bradley J, Breen J E, Payne B, Williams P & Green M J (2010) The use of a cephalonium containing dry cow therapy and an internal teat sealant, both alone and in combination. Journal of Dairy Science 93 (4), 1566–77 PubMed.
  • McDougall S, Bryan M & Tiddy R M (2009) Effect of treatment with the nonsteroidal antiinflammatory meloxicam on milk production, somatic cell count, probability of re-treatment, and culling of dairy cows with mild clinical mastitis. Journal of Dairy Science 92 (9), 4421–31 PubMed.
  • Pyörälä S (2009) Treatment of mastitis during lactation. Irish Veterinary Journal.
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  • Bannerman D D (2008) Pathogen-dependent induction of cytokines and other soluble inflammatory mediators during intramammary infection of dairy cows. Journal of Animal Science 87, 10–25 PubMed.
  • Dogan B, Klaessig S, Rishniw M, Almeida R A, Oliver S P, Simpson K & Schukken Y H (2006) Adherent and invasive Escherichia coli are associated with persistent bovine mastitis. Veterinary Microbiology 116 (4), 270–282 PubMed.
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  • Burvenich C, Van Merris V, Mehrzad J, Diez-Fraile A & Duchateau L (2003) Severity of E. coli mastitis is mainly determined by cow factors. Veterinary Research, 34 (5), 521–64 PubMed.
  • Constable P D & Morin D E (2003) Treatment of clinical mastitis: Using antimicrobial susceptibility profiles for treatment decisions. Veterinary Clinics of North America - Food Animal Practice 19 (1), 139–155 PubMed.
  • Yagi Y, Shiono H, Shibahara T, Chikayama Y, Nakamura I & Ohnuma A (2002) Increase in apoptotic polymorphonuclear neutrophils in peripheral blood after intramammary infusion of Escherichia coli lipopolysaccharide. Veterinary Immunology and Immunopathology 89 (3-4), 115–125 PubMed.
  • Rossitto P V, Ruiz L, Kikuchi Y, Glenn K, Luiz K, Watts J L & Cullor J S (2002) Antibiotic Susceptibility Patterns for Environmental Streptococci Isolated from Bovine Mastitis in Central California Dairies. Journal of Dairy Science 85 (1), 132–138 PubMed.
  • Bradley A J & Green M J (2001) An Investigation of the Impact of Intramammary Antibiotic Dry Cow Therapy on Clinical Coliform Mastitis. Journal of Dairy Science 84 (7), 1632–1639 PubMed.
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  • Kimura K, Goff J P & Kehrli M E (1999) Effects of the Presence of the Mammary Gland on Expression of Neutrophil Adhesion Molecules and Myeloperoxidase Activity in Periparturient Dairy Cows. Journal of Dairy Science 82 (11), 2385–2392 PubMed.
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  • Green M J, Cripps P J & Green L E (1998) Prognostic indicators for toxic mastitis in dairy cows. The Veterinary Record 143 (5), 127–30 PubMed.
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  • Pyörälä S, Kaartinen L, Käck H & Rainio V (1994) Efficacy of Two Therapy Regimens for Treatment of Experimentally Induced Escherichia coli Mastitis in Cows. Journal of Dairy Science 77 (2), 453–461 PubMed.
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Other sources of information

  • WHO Advisory Group on Integrated Surveillance of Antimicrobial Resistance (AGISAR) (2011) Critically Important Antimicrobials for Human Medicine - 3rd Revision 2011. World Health Organization, 1–38.

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