Sub Clinical Mastitis (SCM)

  • Most prevalent form of mastitis - causes about 70% of the losses due to mastitis.
  • Causes heavy losses due to its prolonged effect throughout lactation.
  • The other forms of mastitis (clinical or chronic) develop from this stage.



  • No specific symptom seen except a  slight decrease in milk production.
  • Cannot be normally detected since there is no physical changes in udder or milk.




  • CMT - Equal quantities of milk and CMT reagent are mixed by rotating, SCM milk will form a gel. CMT reaction  may disappear within 20 seconds  , readings  must therefore be taken fast. Also check each quarter separately.
  • CMT may give false positive reaction in very early (less than 10 days) lactation or when animal is almost dry.
  • Strip cup test - Small flakes are present in SCM milk when viewed against a black surface, size of flakes increase with the degree of SCM.
  • Paper test -  Green colour is indicative of SCM.
  • Field mastitis test  - Can be carried out like CMT using using concentrated detergent solution instead of CMT reagent.



  • All the points mentioned for prevention of ‘clinical mastitis’ are relevant here too.
  • Test for the occurrence of SCM in your animals at least once a week.
  • Each quarter should be separately tested.
  • Newly purchased animals should be tested first for SCM and treated if found positive before mixing them with the herd.
  • SCM positive animal (s) should always be milked at the end.
  • If animals are tethered in open, change places frequently.
  • Ideally, no lubricant should be used during milking. If used, it should be heated daily before use.



  • Consult a veterinarian for proper treatment.
  • The chances of curing SCM is much higher than a clinical or chronic case.
  • Timely treatment of SCM will also reduce the chances of clinical  and chronic  cases of mastitis.


                                             Treatment of SCM will greatly reduce losses