Mastitis Flashcards
(26 cards)
What are the three main defining factors of mastitis presentation?
Clinical or subclinical - Dry or lactating period - Contagious or environmental
What is the average prevalence of mastitis in the UK?
35 cases/100 cows/year
What loses does mastitis cause?
Loss of actual and potential milk - Possible residues in milk from treatment - High somatic cell count (SCC)
What happens in a Grade 1 mastitis case?
Milk change only, decreased yield
What happens in a Grade 2 mastitis case?
Acute - Milk changes, changes in udder, decreased yield
Chronic - Persistent changes same as above
What happens in a Grade 3 mastitis case?
Same as grade 2 (milk and udder changes) but a systemically sick cow
How do you detect a subclinical case of mastitis?
Increased SCC - positive in California Milk Test - Reduced yield
Which bacteria are involved in chronic/subclinical mastitis?
Staph. aureus - Staph. uberis - Staph. agalactiae - Corynebacterium bovis
Why should mastitis cases almost always have a bacterial culture test?
Never tell on clinical signs what causes it - Allows selection of right antibiotics
Where do contagious mastitis causing bacteria tend to live? What sort of mastitis do they cause?
In the udder and teat skin - Cause subclinical infection
What are the main contagious pathogens that cause mastitis?
Streptococcus agalactiae - Strep. dysgalacitae - Staph. aureus - Strep. uberis
Where do environmental mastitis causing pathogens come from? Why?
Environment - Poor farm hygiene
What sort of mastitis do environmental pathogens cause?
Very serious acute
What are the environmental mastitis causing bacteria?
E coli - Strep. uberis - Klebsiella - Coliforms - Bacillus cereus
What does bulk tank SCC indicate?
Prevalence of subclinical mastitis in a herd
What is the target for Bulk Milk Somatic Cell Count (BMSCC)? When would intervention be needed? When would a farm be penalised? When can it not be sent for human consumption?
200,000 - >400,000
Outline the 5 point plan for treating mastitis on a farm
1) Prompt detection and treatment of clinical cases
2) Post milking teat dip
3) Dry cow therapy
4) Cull persistent offenders
5) Regular servicing and maintenance of milking machine
What is classes as a persistent offender of mastitis?
3 or more cases during one lactation
What is the most common entry of organisms into the mammary glands? What are the other two sites of entry?
Galactogenic (via teat canal) - Haematogenous - Percutaneous
What are the three barriers of the teat canal that prevent entry of infection?
Smooth muscle sphincter - Keratin from epithelium - Furstenburg’s Rosette
How does Keratin from epithelium stop infection of teat canal?
Contains cationic proteins the lyse gram +ve bacteria (Streps and Staphs) - Contains fatty acids which act as bacteriostatic and bactericidal
How does the Furstenberg’s Rosette stop infection of the teat canal?
Prevents physical entry - Fatty acids and cationic proteins - Subepithelial plasma cells which produce immunoglobulin
What humoral factors resist infection of the mammary glands? How?
Lactoferin (binds iron making it unavailable for bacteria) - Defensins (antmicrobial peptides) - Immunoglobulins (IgG,IgM and IgA)
What is the process of subclinical mastitis?
Initial flare up - fibrosis repair - further flare ups - prgressive fibrosis
