Mastitis 2

Question 1

linear score is better for…

Answer 1

looking at groups of cows

Question 2

cut off for SCC where one or more quarters are affected?

Answer 2

200,000

Question 3

what are the two main ways to diagnose mastitis?

Answer 3

milk culture: gold standard, in a lab, in clinic, or on farm

PCR: highly sensitive, can identify dead bacteria, but difficult to interpret

Question 4

what are the pros and cons of doing a lab milk culture?

Answer 4

pros: highly triained staff using special equipment, they will find the pathogen no matter what, use specialized media, can isolate the bacteria down to the species level (PCR isoalte or MADLI-TOF)

cons: time and cost

Question 5

pros and cons of in clinic milk culture?

Answer 5

often only an incubator and simple media plates such as bi plates like agar and mcconkey OR tri or quad plates

it’s faster than sending it to a lab, but the results are less specific

Question 6

what types of bacteria grow on the following media: blood agar, maconckey

Answer 6

blood agar: gram neg and pos
maconckey: gram neg only

Question 7

pros and cons of on farm milk culturing?

Answer 7

pros: rapid results so you can make immediate treatment decisions (can reduce your antibiotic use), usually bi or tri plates being used which are cheaper

cons: wont get to the species level and youll have to keep frozen samples in case you want further diagnostics

Question 8

why is it so important to do culture based mastitis therapy? why not just do no culture at all?

Answer 8

knowing the pathogen reduces the use of IMM antimicrobials for clinical cases by a lot!! (IMM is intramammary)

for non severe clinical mastitis cases, there is no difference in clinical outcome waiting up to 24 hours to get results to decide therapy

Question 9

how will you treat the following:
- severe mastitis
- moderate mastitis with gram positive growth with a low likelyhood of cure
- moderate mastitis with gram positive growth with a high likelihood of cure
- moderate mastitis with gram neg growth
- moderate mastitis with no growth

Answer 9

• supportive care and antibiotics
• no IMM tx, NSAIDs
• IMM tx and NSAIDs
• NSAIDs only, no antibiotics
  -NSAIDs only, no antibiotics

note that IMM means intramammary antibiotics

Question 10

pros and cons of composite vs quarter sampling of milk

Answer 10

compositie samples: risk of getting a contaminated sample increases, but good if youre wondering if a cow has a contagious mastitis pathogen

quarter samples: most likely to give a result–>we only want bacteria that are present on the INSIDE of the mammary gland

Question 11

what is the proper way to store milk culture samples

Answer 11

• they are ok at room temp for less than 1 hour
• can be in frig for 2 days
• frozen they are good up to 8 weeks

Question 12

how does freezing affect the pathogens in a milk sample?

Answer 12

freezing the sample slightly decreases E coli and increases staph aureus and slight decrease in mycoplasma if frozen for more than 1 week

Question 13

why is the preferred route of admin IMM?

Answer 13

because it’s highly concentrated in the milk and there’s lower consumption of the antibiotic

Question 14

IMM works well for ____ but doesn’t work well for ____

Answer 14

gram positives, gram negs

Question 15

how long is treatment with a superficial invader vs an invader of the deeper secretory tissues?

Answer 15

superficial: 2-3 days
deep: 5-8 days

Question 16

what are the 2 options for antibiotics in lactating dairy cows?

Answer 16

Cefa-Lak (cephapirin sodium)
Spectromast (ceftiofur hydrochloride)

Question 17

Cefa-Lak is labelled for…

Answer 17

clinical mastitis caused by strep agalactiae and staph aureus

the dose is 200mg once and then repeated in 12 hours and this isn’t good enough for staph aureus which invades deep tissues

Question 18

Spectromast is labelled for…

Answer 18

clinical mastitis caused by E coli, strep dysgalactiae, and NAS, AND for subclinical mastitis associated with NAS or strep dysgalactiae

uhhh it wont work for E coli cuz IMM doesn’t work on gram negs

Question 19

why do cefa-lak and spectromast suck

Answer 19

because they have huge label claims that are FAKE NEWS and you’re often forced to go off label because the dose or frequency isn’t good enough…often need a CG FARAD and then milk withholds become a pain

Question 20

which NSAID should be used for mastitis?

Answer 20

metacam

Question 21

why do we give intramammary antibiotics to dry cows?

Answer 21

to prevent new intramammary infections and to treat any existing intramammary infections

IMM abs work better in an involuted udder compared to a lactating one!

Question 22

what is blanket drug cow therapy?

Answer 22

the largest use of prophylactic antimicrobials in the dairy industry and is banned in some countries

selective dry cow therapy can be used on some farms (only treat some of the cows instead of all)

Question 23

why is the abs dose higher for dry cows?

Answer 23

for longevity and to get MIC to last as long as possible

Question 24

list some examples of abs that can be used in dry cows

Answer 24

Cefa-dry, Spectramast, Dry-Clox

Question 25

what are teat sealants and why are they used? proper way to use?

Answer 25

they form a physical barrier in the teat canal. they should be applied whether dry cow abs are being used or not. it seals off the teat and is then hand stripped out at first milking

***MUST BE DONE ASEPTICALLY otherwise youre trapping bacteria in the udder and sealing it in there=fatal

Question 26

true or false: the E coli vaccine is not considered core for dairy cows

Answer 26

FALSE it IS a core vaccine! use killed vaccines that require boosters (only short period of immunity but works really well)

Question 27

when should you NOT give E coli vaccines (they are bacterins)

Answer 27

too close to calving, or with another bacterin vaccine

it can cause abortions

Question 28

what are the two most common mastitis pathogens for beef cows?

Answer 28

staph aureus and corynebacterium bovis

Question 29

how is beef cow mastitis treated?

Answer 29

usually treat the gram pos infections, IMM therapy works, but can use injectables (safer)

Question 30

you go see a dairy cow with a big ole’ full thickness laceration to one of her teats. How will you fix this?

Answer 30

suture it closed in 3 layers: submucosa, intermediate layer, then skin, DO NOT include mucosa in the first layer.

use a ring block at base of teat with lidocaine (no epi!! this causes vasoconstriction and can create more problems)

Question 31

true or false: longitidinal lacerations heal better than horizontal ones

Answer 31

true because of blood supply not being cut off as much

Question 32

true or false: lacerations at the base dont heal as well as at the apex

Answer 32

FALSE they heal better at the base than at the apex

Question 33

when would you need to do a teat amputation?

Answer 33

when teat damage is irreversible

Question 34

how do you amputate a teat?

Answer 34

drain the quarter of all milk, and infuse IMM abs. then perform a ring block at the base of the teat and clamp the base of the teat, cut the skin around proximal 3rd of teat, then tighly appose the submucosa and intermediate layers with a continuous horizontal mattress suture

Question 35

lactococcus and enterococcus are what kind of mastitis pathogen

Answer 35

environmental, similar to strep uberus