Cattle/sheep infectious disease (Yr3)

Question 1

what is a microbiome?

Answer 1

genetic material of all the microbes within the animal (bacteria, fungi…)

Question 2

what is metritis?

Answer 2

inflammation of uterus caused by bacterial infection producing a reddish/brown foul smelling uterine exudate less than 21 DIM

Question 3

what pathogens could be involved in metritis?

Answer 3

E. coli (main pathogen)
Trueperella pyogenes
Fusobacterium necrophorum

Question 4

is E. coli gram positive or negative?

Answer 4

negative

Question 5

is Fusobacterium necrophorum gram postive or negative?

Answer 5

negative (anaerobic)

Question 6

what is the pathogenesis of Fusobacterium necrophorum infections?

Answer 6

produces leukotoxin which causes death of leukocytes, macrophages and epithelial cells leading to necrotic lesions

Question 7

is Trueperella pyogenes gram positive or negative?

Answer 7

positive

Question 8

what is endometritis?

Answer 8

inflammation of the endometrium, with purulent discharge when cow is over 21 days in milk

Question 9

what is subclinical endometritis?

Answer 9

inflammation of endometrium categorised by increased neutrophils on cytology

Question 10

what causes viral vaginitis?

Answer 10

bovine herpesvirus 1 (IBR virus)

Question 11

what is the main clinical sign of bovine herpesvirus relating to reproduction?

Answer 11

abortions

Question 12

is Campylobacter fetus venerealis gram positive or negative?

Answer 12

negative

Question 13

what does Campylobacter fetus venerealis cause?

Answer 13

chronic endometritis
early embryonic deaths and abortions
(STD so need bulls to spread it)

Question 14

how can you protect against IBR?

Answer 14

vaccinate (protection in face of outbreak)

Question 15

what are the two biotypes of bovine viral diarrhoea?

Answer 15

non-cytopathic (rarely causes clinical disease)
cytopathic (associated with PIs and mucosal disease)

Question 16

what are the presentations of BVD depending on when infection occurs?

Answer 16

0-100 days - abortion/resorption
100-120 dyas - immunotolerance (PI calf)
120-285 days - congenital lesions or abortion

Question 17

what are PI calves antigen and antibody status?

Answer 17

antibody negative
antigen positive

Question 18

what are the main congenital abnormalities seen with BVD?

Answer 18

cerebellar hypoplasia
microphthalmia
cataracts

Question 19

what are the clinical signs of leptospirosis?

Answer 19

poor fertility, abortions, weak calves, RFM
(can shed without clinical signs)

Question 20

how can leptospirosis be diagnosed?

Answer 20

bulk milk sampling and identification in abort tissues and blood

Question 21

what serovar of Salmonella is associated with abortions?

Answer 21

S. dublin

Question 22

what is somatic cell count?

Answer 22

number of cells per ml in milk (epithelial and white blood cells mainly)

Question 23

how can mastitis be categorised?

Answer 23

clinical and subclinical

Question 24

what are the grades of clinical mastitis?

Answer 24

1. mild changes in milk
   2A. acute with changes to milk and hot painful udder
   3C. chronic with changes to milk and hard lumpy udder
2. changes to milk/udder with systemically sick cow

Question 25

what are the two categories of mastitis pathogens?

Answer 25

contagious environmental

Question 26

what are the common environmental mastitis pathogens?

Answer 26

Streptococcus uberis E. coli (coliform) Klebsiella pneumoniae (coliform)

Question 27

what are the common contagious mastitis pathogens?

Answer 27

Streptococcus uberis Staphylococcus aureus Streptococcus dysgalactiae Streptococcus agalactiae Mycoplasma spp.

Question 28

what is the difficulty of culturing/testing for mastitis pathogens?

Answer 28

contamination when sampling not shedding when sampled poor storage/handling unknown pathogen fastidious pathogen

Question 29

is Staphylococcus aureus gram positive or negative?

Answer 29

postive cocci

Question 30

how is mastitis caused by Staphylococcus aureus spread?

Answer 30

cows/fomites teat sucking (found in tonsils) fly spread

Question 31

what is the pathogenesis of mastitis caused by Staphylococcus aureus?

Answer 31

damages duct system leading to deep pockets of infection in secretory tissues and abscess formation

Question 32

why are antibiotics poorly accessible to Staphylococcus aureus mastitis infections?

Answer 32

it is an intracellular bacteria that forms a biofilm with many virulent factors

Question 33

why may a cow with Staphylococcus aureus mastitis test negative to it?

Answer 33

it is intermittently shed in milk

Question 34

what grade mastitis does Staphylococcus aureus cause?

Answer 34

can cause any grade