Animal Health & Welfare

Mastitis is one of the most costly diseases to the dairy farmer, and poses a significant welfare issue for those animals affected. The pages in this section are designed to help highlight the primary causes of mastitis, and illustrate how management factors can be implemented for the initial reduction and future control of mastitis.

Mastitis is a complex infectious disease of the mammary gland (udder) which is thought to cause pain, and as such, can negatively impact the welfare of those animals affected. Well over 100 organisms have been associated with the condition causing either clinical mastitis (which is recognised by the herdsman or veterinarian) or subclinical mastitis (which is only detected by further testing of the milk).

However, the major pathogens include: E.coli, Streptococcus uberis (both environmental organisms), Streptococcus dysgalactiae (acts as an intermediate), Staphylococcus aureus and Staphylococcus agalactiae (both contagious organisms which spread in the parlour).

The following table shows the proportion of major pathogens isolated from mastitis submissions in Scotland (1998-2003)

Proportion of all mastitis diagnosis	1998	1999	2000	2001	2002	2003
E. coli	28%	24%	24%	24%	23%	19%
Staph. aureus	21%	21%	20%	20%	28%	29%
Strep. agalactiae	1%	3%	2%	2%	2%	2%
Strep. dysgalactiae	7%	8%	8%	7%	6%	4%
Strep. uberis	15%	16%	18%	19%	18%	18%
Total diagnoses	819	869	808	861	1125	950

 

Primary causes of mastitis

Contagious pathogens: Staphylococcus aureus, Streptococcus agalactiae, Streptococcus uberis, Streptococcus dysgalactiae, Corynebacterium bovis, coagulase negative staphylococci
Environmental pathogens: Enterobacteriaceae (including Eschericia coli), Streptococcus uberis, yeasts and moulds

For details and advice on managing mastitis and precautions and treatments, refer to the menus below.

Derived costs of mastitis (per case)

• Milk discarded during treatment
• Reduction in milk yield for the current and subsequent lactations
• Reduced milk quality through increases in cell count and bacterial counts
• Pharmaceuticals used in treatment
• Farm labour costs in tubing, discarding milk and caring for sick cows
• Veterinary fees

See the link on the right to explore the economics of mastitis.