Mastitis

• • Mastitis can take many forms from invisible to fatal.

• • All forms are associated with production losses.

• • Mastitis may be caused by many different bacteria.

• • The main bacteria causing mastitis may differ considerably between farms and require different mastitis prevention or treatment strategies.

• • Mastitis control plans should therefore be tailored to individual farms.

• • Prevention is better than cure and is based on reducing exposure to bacteria through good hygiene.

• • Hygiene is important for lactating cows, dry cows and heifers.

• • For contagious mastitis, milking parlour hygiene is most important.

• • For environmental mastitis, hygiene in the barn, alleyways or pasture is most important.

• • There is no one-on-one relationship between bacterial species and transmission route, but some bacteria are more likely to be contagious than others.

• • Antimicrobial use and antimicrobial resistance are of increasing concern.

• We must use antimicrobials carefully and selectively in dairy farming and concentrate efforts on disease prevention.

cute mastitis affects between 4-5% of lowland ewes and 1-2% of hill ewes each year.  Chronic mastitis affects between 1-15% of ewes.

• Ewe mastitis has important impacts on ewe mortality, premature ewe culling, lamb mortality and growth.

• Mastitis can be peracute, acute, chronic and clinical or sub-clinical depending on the severity and duration of clinical signs in the ewe.

• The main risk period for clinical mastitis is the first week post lambing to around peak lactation at 3-4 weeks post lambing.

• The most common bacteria found in mastitis cases are Staphylococcus aureus and Mannhaemia haemolytica, although other bacteria may occur.

• The bacteria enter the udder through the teat canal, some are transferred from the lambs’ mouths when sucking.

• Factors which damage the ewes’ teats, e.g. chapping, orf or excess sucking by hungry lambs, increase the risk of a ewe developing mastitis.

• Ewes feeding 3 or more lambs are at increased risk of mastitis.

• Treatment of ewes with mastitis should be prompt and is aimed at saving the ewe’s life as damage to the udder can be permanent.

• Ewes chronically affected by mastitis should be culled.

• All ewes’ udders should be inspected at weaning and at the pre-tupping check.

• Preventative strategies for mastitis should be discussed with your vet as part of your health planning for the flock.  Consideration should be given to ewe and lamb nutrition pre and post lambing, maintaining good ewe teat condition, and environmental hygiene.

• The viral infection Maedi-Visna can cause chronic mastitis in sheep and requires a separate approach.

Moredun have a research interest in novel vaccine candidates and approaches for protection of dairy cattle against mastitis.