Aetiology, Pathogenesis and Pathology of Mastitis Flashcards
When is the cow at risk of mastitis?
Lactating
Dry cow
What is the dominant pathogen in the UK causing lactating bovine mastitis?
Strep uberis
What is the dominant pathogen in the UK subclinical lactating cow mastitis?
Coagulase negative dominates
What is the habitat of Staph aureus? How does it enter the teat?
Skin and mucous membranes, enters through teat canal
What is the problem with treating staph aureus mastitis?
70% of strains are betalactam positive
How does staph aureus avoid immune response?
Intracellular location
Staph aureus does not always invade udder tissues - how does it cause inflammation?
Due to immune response to organisms adherent to internal duct and sinus epithelium
What are the 7 pathogenecity factors for staph aureus?
a-toxin b-toxin TSS-1 (superantigen) polysaccharide capsule Protein A Enxymes Fibronectin-binding protein
What is the natural habitat of strep agalactiae?
Teat canal of udder
What is the natural habitat of strep dysgalactiae? How does it gain entry in mastitis?
Outside the udder teat
Requires trauma or wound to initiate invasion
What type of infection does strep agalactiae cause?
Slow, progessive, chronic
What type of infection does strep dysgalactiae cause?
Not host adapted - more acute and inflammatory than others (e.g. step agalactiae)
What is the natural habitat of Strep uberis? How does it gain entry in mastitis?
In the environment (faeces?)
Requires trauma or wound to initiate invasion
What vaccine is available for E. coli?
Killed J5
What key features are there about E coli in relation to mastitis?
AB resistance
Toxigenicity factors
What pathogen causes a mastitis that results in a massive decrease in milk yield?
Mycoplasma bovis
What is the natural habitat of mycoplasma bovis? How does it gain entry in mastitis?
Genital and reproductive tract
May reach the udder by haematogenous spread
What are the 3 primary agents involved in dry cow mastitis?
Trueperella pyogenes
Strep dysgalactiae
Peptostreptococcus indolicus
When do many lactating mastitis infections being?
During the dry period hence therapy can be highly effective in prevention
What are the 5 main pathogens involved with mastitis in ewes?
Mannheimia haemolytica Staph aureus E. coli Strep Mycoplasma agalactiae
What pathogen involved with mastitis in ewes is a notifiable disease?
Mycoplasma agalactiae
What are the 4 disease process involving the mammary gland?
Disease of skin of teats
Pathogens transmission to young
Neoplasia
Inflammation
What are the 3 routes of entry of microorganisms into the mammary gland?
- Galactogenic
- Haematogenous
- Percutaenous
What are the 3 clinical presentations of mastitis?
- Peracute and life-threatening
- Acute with or without systemic signs
- Chronic
What is peracute mastitis?
Gangenrous mastitis esp staph aureus
Toxic mastitis coliforms
Mostly occur around parturition and death can occur within hours
How does peracute mastitis appear grossly?
Swollen, painful quarter
Rapid progession to moist gangrene
Dark-blue to black in colour, blistering and oozing serum
Becomes cold to touch
How does chronic subclinical mastitis appear grossly?
In chronic stages, gland is hard and atrophic
