Alasdair Marshall BVSc MRCVS, Molecare Veterinary Services
Typically, it is associated with straw yards and poached fields, therefore Strep uberus is traditionally thought of as an environmental pathogen. Recent research has shown that Streptococcus uberus is a pathogen with many different strains, and certain strains are more likely to be spread from the environment to the cow, while other strains are more likely to spread from cow to cow (contagious spread). Different strains have different abilities to reproduce and survive in the cow/environment, and differ in their capacity to maintain infection in ‘carrier cows’.
This results in a bug with the ability to cause problems from many different angles and requires a whole farm approach to help bring outbreaks under control. This has considerable significance on the treatment protocols and prevention which must be drawn up on an individual farm basis.
Common risk factors and control measures on farm are:
|Poaching in fields||– Often weather related!
– Regular rotation of calving fields if applicable
– Smaller groups of cows
– Track and gateway maintenance
|Straw bedding||– Ensure stocking rates are correct for lactating herds
– Regular cleaning and bedding up with dry straw
– Calving yard hygiene vital for mastitis, metritis and calf health rates
– Location of water troughs and passages
|Warm, humid sheds||– Ensure adequate drainage slopes of yards
– No overstocking
– Ensure correct ventilation inlet and outlet ratios in lactating sheds
|Contaminated teats||– Milking parlour hygiene
– Correct use of pre-dips
– Keeping tails clipped and udders singed will all help reduce pathogen loading
|Strep uberus carrier cows||– Early id of cases
– Culture to identify repeat/high SCC cows with farm specific plan for them (milk last/separately, treat, cull)
– Appropriate dry therapy/ selective dry therapy as required for individual farms
|Other immune suppressive factors||– BVD control
– Fluke control
– Nutrition- e.g. Selenium levels
|Damaged teats||– Parlour maintenance and liner changes
– 30 minutes standing time post milking to allow teat
– Stocking density esp. in straw yards
Good records and regular cultures of clinical cases will help to form suitable treatment plans and help identify risk areas on individual farms.
For more information on Molecare Veterinary Services, please phone 01392 872934 or visit www.molecarevetservices.com