Mastitis Flashcards
Define mastitis
Inflammation of the mammary gland for any reason
List causes of mastitis
- Bacterial
- Viruses
- Fungi
- Physical e.g. trauma
- Toxins
- Neoplasi
Compare acute vs chronic disease
- Acute: sudden onset, often severe signs of disease
- Chronic: disease persists for a prolonged period of time, usually subclinical or mild signs of disease
What are the 2 classifications of mastitis?
- Contagious
- Environmental
Define contagious mastitis
Spread from cow to cow
Define environmental mastitis
Pathogen lives in environment and causes infection from environment to cow
What is the main method of transmission in contagious mastitis?
Milking process, infected cows are primary reservoir of infection
What are the main bacteria that cause contagious mastitis?
- Staphylococcus aureas
- Streptococcus agalactiae and dysgalactiae
Describe the clinical signs of contagious mastitis
- Mild-moderate in severity
- Often chronic infection
- Associated with high somatic cell counts
- Infected quarters intermittently shed large numbers of bacteria into milk often without clinical signs
Describe Staphylococcus aureus in mastitis
- Gram +ve cocci
- Chronic, mild or subclinical mastitis
- High somatic cell counts
- Occasionally causes gangrenous mastitis
Describe Streptococcus agalactiae in mastitis
- Gram +ve cocci
- Highly conagious
- Obligate udder pathogen living in gland
- Now rare, once removed from herd will not return (only found in udder)
- High somatic cel count
Describe Streptococcus dysgalactiae in mastitis
- Gram +ve cocci
- Usually considered contagious but can survive in environment
Outline transmission of pathogens causing mastitis during milking
- Infected cow in
- Contagious milk contaminates milker’s hand or equipment
- Infects sbsequent animals
- Milking most important point of control for contagious mamstitis
List bacteria important in environmental mastitis
- E. coli
- Streptococcus uberis
- Streptococcus dysgalactiae
Describe environmental mastitis
- Infection acquireed directly following contact with pathogens in environment
- Environment is primary reservoir
- Most cases milk-moderate, less likely to eastblich sub-clinical disease (except S. uberis)
Describe E. coli in mastitis
- Gram -ve bacilli
- Minority of cases by E. coli are acute and severe often around calving
- chronic infection rare
Describe Streptococcus uberis in mastitis
- Gram +ve coccus
- Most common cause of clinical mastitis in UK
- Cows on straw yards
- Chronic infection, high somatic cell count
Outline how infection with environmental mastitis occurs
- Contamination before milking
- Pathogens into udder during milking when teats open
Compare clinical vs sub-clinical disease
- Clinical: identified based on clinical signs
- Sub-clinical: disease present but no visual signs, additional tests required for diagnosis, presents greater transmission risk
List clinical signs of mastitis
- Changes to milk
- Inflammation of the gland
- Systemic illness
Describe some changes to milk that occur in mastitis
- Clots, lumps, strings present
- Changes in colour (off whites/yollows/reds)
- Changes in consistency
- Smell
Describe the appearance of an inflamed mammary gland
- Swollen
- Hot
- Hard
- Painful
- Possibly necrosis of the qaurter
Describe teh appearance of systemic illness with mastitis
- Varying severity
- Reduced milk yield
- Pyrexia
- Anorexia
- Recumbency
- Tachycardia
- Tachypnoea
- Collapse
- Death
Describe a grade 1 mastitis
- Mild
- Changes to milk only
- Clots, change of colour, change of consistency
Describe a grade 2 mastitis
- Moderate
- changes to udder
- Heat, pain, swelling
Describe a grade 3 mastitis
- Changes to the cow (sick cow)
- Pyrexia, anorexia, tachycardia, tachypnoea plus others
What are the points in the 5 point plan for mastitis control?
- Post0milking disinfection
- Treat clinical cases promptly
- Dry cow therapy for all animals
- Cull chronically infected animals
- Milking machine maintenance
Describe the post-milking teat disinfection in the control of mastitis
- Anythign on teat from milking killed
- Immediately after unit removal
- Dips or sprays
- Cover all sides on all teats
- Many disinfections
- For control of contagious mastitis
Describe the treatment of clinical mastitis
- Identify and treat rapidly
- Aseptic infusion of intra-mammary antibiotic tubes most common
- Wide range of products
- Injectable antibiotics also used
Describe dry cow therapy in the control of mastitis
- Cures existing infections, prevents new infections in dry period
- Cure existing: long acting antibiotic tubes infused at drying off
- Prevent new: antibiotic dry cow tubes or internal teat sealant
- Aim to use more non-antibiotic prevention
Describe culling of chronically infected cows in the control of mastitis
- Represent major reservoir
- Culling from herd prevents contagious spread
Describe milking machine maintenance in the control of mastitis
- Act as fomite for transmission of contagious
- Vacuum instabilities can drive pathogens into quarter
- Regular maintenance important
How can mastitis in the herd be monitored?
- Maintain and complete accurate records
- Sample proportion of cases for bacteriological analysis to identify pathogen causing most disease on farm
- Different methods for clinical and subclinical
Describe the monitoring of sub-clinical mastitis
- Usually contagious pathogens
- Infection does lead to to elevated somatic cell count
- Large number infected BMSCC wll rise for example
Describe monitoring of sub-clinical mastitis using bulk milk somatic cell count
- Guide to levels of subclinical in herd
- To be legal in europe, 3 month geometric mean of BMSCC of a dairy herd must be before 400,000cells/ml
Describe the monitoring of sub-clinical mastitis using indvidual cow somatic cell count
- Samples from individaul cows collected regularly usually montly) analysed
- National milk records
- Problem cows identified and managed appropriately
Describe the California Milk test in the monitoring of subclinical mastitis
- Binds to somatic cells, not bacteria i.e. not a measure for infection
- Simple, cheap, cow side indirect measure of SCC
- Identify problem cows and infected quarters
- Milk mixed with coloured detergent, reacts with cells present, degree of thickenign directly proportional to number fo cells present (i.e. thicker = more cells)
Outline the control of environmental mastitis
- Ensure environment is clean
- Pre-milking disinfection
Explain how pre-milking disinfection helps control environmental mastitis
- Rapid bacterial kill time
- Applied, leave for 60s, dry with clean towel
- Removes pathogens before milking so cannot get into udder when teats open for milking
- If very dirty need to thoroughly clean
- Cannot use post-dips as pre-dips
What is another potential cause of alumpy udder in pigs?
Actinomyces (chronic mastitis, also causes lumpy jaw)
