Dairy Medicine: Contagious Mastitis

Question 1

proliferative teat lesion causes

Answer 1

pseudopox

Question 2

ulcerative teat lesion causes

Answer 2

vesicular stomatitis (paramyxovirus)
herpes mammilitis (BHV 2 & 4)
bluetongue virus

Question 3

CMT result interpretations

Answer 3

neg + trace = normal
negative: 0-200,000
trace: 150,000-500,000
1+: 400,000-1,500,000
2+: 800,000-5,000,000
3+: 5,000,000+

Question 4

classic gangrene etiology

Answer 4

goats: S.aureus
sheep: Manheimia haemolytica
cattle: Clostridium perfringens
misc: Bacillus cereus

Question 5

udder edema

Answer 5

predisposition: high salt (Na, K) high concentrate diet
median suspensory ligament prepubic tendon breakdown
Tx: diuretics

Question 6

contagious pathogens

Answer 6

Streptococcus agalactiae
Staphylococcus aureus
Mycoplasma
Streptococcus dysgalactiae
Corynebacterium bovis

Question 7

Streptococcus agalactiae

Answer 7

gram (+) obligate MG pathogen
subliclinical
HIGH SCC
sensitive to treatment during lactation,
---eradication possible
CAMP reaction

Question 8

Staphylococcus aureus

Answer 8

gram (+) non-obligate pathogen of MG
major source of infection= infected quarters
– chronic subclinical infections high risk for herdmates
spread by poor milking hygiene
subclinical, acute, chronic, acute gangrenous mastitis
alpha toxin: tissue damage
microabcesses: fibrosis

Question 9

Mycoplasma

Answer 9

facultative intracellular pathogen
highly contagious + large numbers shed in milk
not typically systemically ill
signs in calves: respiratory disese, otitis, arthritis
Markedly decreases milk yeild
antibiotic resistant

Question 10

Streptococcus dysgalactiae

Answer 10

Contagious and environmental

lactating cow treatment possible

Question 11

Corynebacterium bovis

Answer 11

commensal of udder and reproductive tract
low grade mammary gland leukocytosis
—SCC 200-400,000