Mastitis Flashcards
What can cause mastitis?
Bacteria – most common Viruses Fungi Physical e.g. trauma Toxins Neoplasia
What are the clinical signs?
Changes to the milk (clots, change in colour/consistancy, smell)
Inflammation of the gland (swollen/hard/hot/necrotic)
Systemic illness
What are the grades of mastitis?
Grade 1 (Mild)
Changes to the milk only
Clots / Change of colour / Change of consistency
Grade 2 (Moderate)
Changes to the udder
Heat / Pain / Swelling
Grade 3 (Severe) Changes to the cow (Sick cow) Pyrexia (a temperature) / Anorexia (decreased food intake) / Tachycardia (increase in heart rate) / Tachypnoea (increase in respiratory rate) plus others
How can mastitis present?
Acute disease: Sudden in onset, Often severe signs of disease
Chronic disease
Disease persists for a prolonged period of time, Usually subclinical or mild signs of disease
What are the two types of bacterial mastitis?
Contagious and environmental
What bacteria cause contagious mastitis?
Staphylococcus aureus – Gram +ve cocci and is often the cause of mild and subclinical mastitis
Streptococcus agalactiae – Gram +ve cocci that are obligate udder pathogens (live in the gland) and highly contagious
Streptococcus dysgalactiae - Gram positive cocci that are considered contagious but can live in the environment
How does contagious mastitis tend to present?
Tends to be mild – moderate in severity
Quarters often remain chronically infected for long periods of time
Associated with high somatic cell counts
Infected quarters can intermittently shed large numbers of bacteria into milk (often without clinical signs)
What bacteria cause environmental mastitis?
Escherichia coli (E. coli) - Gram negative bacilli often acute and severe and around calving Streptococcus uberis (Strep. uberis) - Gram positive coccus, Currently the most common cause of clinical mastitis in the UK, Often associated with cows kept in straw yards, Chronic infection and elevations in somatic cell count are now more common Streptococcus dysgalactiae (Strep. dys) – slightly contagious and slightly environmental
Which type is bacterial mastitis is most likely to be subclinical?
contagious
What is the 5 point plan for mastitis?
- Post milking teat disinfection
Kill any bacteria transferred onto the teat during milking (Contagious pathogens)
Apply immediately after the unit is removed as either dips or sprays but must cover all four sides of all four teats
Various disinfectants (often iodophors – brown in colour) Also contains an emollient e.g. glycerol, to condition the teat skin - Treat clinical cases promptly
Clinical cases should be identify and treated rapidly
The aseptic infusion of intra-mammary antibiotic tubes is the most common treatment - Dry cow therapy for all animals
Cure existing infections - Long acting antibiotic tubes are infused at drying off
Prevent new infections - Either antibiotic dry cow tubes or an internal teat sealant (Sealant is infused into the teat the prevents the acquisition of new infections) - Cull chronically infected animals
Chronically infected cows represent the major reservoir of infection for contagious pathogens.
Culling them from the herd prevents them from infecting other animals - Milking machine maintenance
The milking machine (particularly the liner / cluster) acts as a fomite for the transmission of contagious mastitis
Vacuum instabilities can propel pathogens into the quarter
Regular maintenance of the milking plant is an important part of mastitis control
How should teats be disinfected?
It should be applied and left for at least 60 seconds and dried with clean paper towel
Helps to prevent “Environmental” mastitis
Post dip products can not be used as pre-dips
How can we monitor sub-clinical mastitis?
Usually caused by contagious pathogens (Strep. uberis is increasingly a problem)
However, infection does lead to elevations in somatic cell count so If large number of the herd are infected sub-clinically the BMSCC will rise
What is BMSCC?
Bulk Milk Somatic Cell Count (BMSCC)
A guide to the levels of sub-clinical mastitis in the herd
Milk buyers test bulk milk samples regularly
Milk with lower SCC has a longer shelf life and an increased cheese yield
To be legally saleable in Europe, the three month geometric mean BMSCC of a dairy herd must be below 400,000 cells/ml
Many milk buyers pay bonuses / enforce penalties for milk in BMSCC bands
What is ICSCC?
Samples from individual cows are collected regularly (usually monthly) and analysed
National Milk Records (NMR) are the predominant company although others exist
Problem cows can be identified and managed appropriately
