Bovine udder health Flashcards
What impact does mastitis have on the dairy industry?
Production related disease Endemic disease Welfare issue Public health issue Economic issue Wastage
What is the definition of mastitis?
Inflammation of the udder
What is the definition of an intramammary infection?
Pathogen infection of the udder with or without clinical signs
What are the two clinical presentations of mastitis?
Clinical
Subclinical
What is clinical mastitis?
Inflammation WITH changes in the udder/milk/systemic
What is subclinical mastitis?
Inflammation WITHOUT changes in the udder/milk/systemic
What are the two epidemiological origins of mastitis?
Contagious
Environmental
What are the features of innate immunity of the udder?
Teat sphincter
Keratin plug
Macrophages
Neutrophils
What are features of acquired immunity of the udder?
Immunoglobulins
Lymphocytes
What are the 3 stages of the dry period?
Involution
Steady state
Transition
When is the rate of new mastitis infection highest?
At drying off and calving
How do you diagnose subclinical mastitis?
By detection of immune response - somatic cell count
What tests can you do for subclinical mastitis?
California milk test
Somatic cell count
What is a normal SCC compared to an infected SCC?
Normal - 5-200K
Infected/raised - 200K-5M
What factors affect SCC?
Infection
Age
Stage of lactation - late
What is grade 1 clinical mastitis?
Changes to milk only
What is grade 2 clinical mastitis?
Changes to the udder
What is grade 3 clinical mastitis?
Changes to the cow - sick
What are the major contagious pathogens of clinical mastitis?
Staphylococcus aureus
Streptococcus agalactiae
Mycoplasma
What other minor pathogens can cause clinical mastitis?
Corynebacterium bovis
Trueperella pyogenes
How is staph aureus transmitted?
Mainly cow to cow
What type of infection does staph aureus cause?
Persistent infection
How is strep agalactiae transmitted/ transmitted?
Cow to cow
Which pathogens causing clinical mastitis are now rare?
Strep agalactiae
Mycoplasma
How can you control contagious pathogens?
Milking routine Parlour function Vaccination Culling Nutrition
What are the two methods of treating intramammary infections aside from culling?
In lactation
Dry cow therapy
What type of mastitis is dry cow therapy the best to treat?
Contagious mastitis
What type of mastitis pathogen should you cull?
mycoplasma
Staph aureus
What does corynebacterium bovis cause?
Teat duct infections
What are the major environmental pathogens causing mastitis?
E coli
Strep uberis
Klebsiella
Enterobacter
What are the minor environmental pathogens?
Strep dysgalactiae
Pseudomonas
Nocardia
Yeasts
What types of strep are contagious and what types are environmental?
Agalactiae - contagious
Uberis and dysgalactiae - environmental
When is strep uberis a major problem?
Dry period - bedding
What part of the milking reduces the incidence for environmental mastitis?
Pre milking teat dip/cleaning
What forms after drying off and what is used to replicate it?
Keratin plug
Teat sealant
What type of dry cow therapy is used now?
Selective dry cow therapy
All get teat sealant
Only cows that nead it get antibiotics
How do you treat coliform environmental pathogens (E coli, Klebsiella, enterobacter)?
According to clinical signs - high self cure rate
How do you treat environmental streps (uberis, dysgalactiae)?
Antimicrobial therapy - high recurrence rate if untreated
How do you treat most of the more minor environmental pathogens eg. pseudomonas, serratia, yeasts, nocardia?
Very difficult to cure - cull
What steps are needed for herd level mastitis investigation?
Data collection and analysis
Diagnosis
Herd surveys
What are the signs that the herd has a contagious mastitis problem?
Long duration
Chronic cases
Poor cure rate
Subclinical
What are the signs that the herd has a environmental mastitis problem?
Seasonal effect
Higher new infection rate rather than chronic cases
