Pharmacology

Question 1

what bacteria are commonly associated with mastitis in dogs?

Answer 1

e. coli
staphylococci
streptococci

Question 2

which antibiotic classes have a spectrum against gram-negative enteric bacteria?

Answer 2

3rd gen cephalosporins
FQs
aminoglycosides

Question 3

Why can we NOT use penicillin to treat a gram - mastitis?

Answer 3

penicillin ONLY has gram - spectrum of coverage in urine.

Question 4

what is the spectrum of 1st generation cephalosporins?

Answer 4

gram +

Question 5

Which antibiotic classes have spectrum against gram + cocci?

Answer 5

penicillin (streps only)
Cephalosporins (1st and 3rd gen)
chloramphenicol
lincosamides
macrolides
potentiated sulfonamides – only in dog/cat

Question 6

which gram + bacteria do FQs and aminoglycosides cover?

Answer 6

staphs only, no streps

Question 7

which antibiotic is SAFEST for dam and babies?

Answer 7

beta-lactams

Question 8

what 2 specific antibiotics are recommended in canine mastitis and why?

Answer 8

cephalexin and clavamox
because they are safe and cover staphs and streps.

Question 9

what are 2 cons of choosing cephalexin or clavamox to treat canine mastitis?

Answer 9

poor action against E. coli
poor penetration into milk

Question 10

what sample is best to submit for culture/sensitivity in a case of canine mastitis?

Answer 10

milk

Question 11

If canine mastitis is caused by E. coli, what is the appropriate antibiotic choice if you didnt already had susceptibility results?

Answer 11

aminoglycosides
fluoroquinolones

Question 12

which antibiotic is NOT a good choice if you’re treating an infection that has an abscess?

Answer 12

trimethoprim/sulfamethoxazole

Question 13

why would you NOT choose amikacin, cefazolin, cefpodoxime, and gentamicin in treating an E. coli induced mastitis infection with an abscess?

Answer 13

these drugs are hydrophilic and will not get into the abscess.

Question 14

what toxicity do you worry about when using enrofloxacin?

Answer 14

cartilage toxicity

Question 15

what routes of administration are appropriate for E. coli mastitis in cows?

Answer 15

IV, SC, or IMM
intramuscular is not preferred due to extended withdrawal period

Question 16

which systemic antibiotic would you choose to treat an E. coli mastitis in cows?

Answer 16

oxytetracycline

Question 17

which antibiotic is NOT labeled for use in dairy cattle and is considered illegal to have ELDU?

Answer 17

enrofloxacin

Question 18

If a drug has a milk withdrawal time of 0, what can you assume?

Answer 18

that is does not even penetrate that site, so it probably shouldnt be used to treat mastitis infections.

Question 19

what intramammary drug if best to treat a cow 14 days post-partum?

Answer 19

Spectrmast LC because she is lactating.
it would be spectramast DC if she was dry.

Question 20

T/F: you can use sulfonamides to treat mastitis in dairy cattle, but not dogs and cats.

Answer 20

false – illegal to use sulfonamides in dairy cattle.

Question 21

Extralabel usage of __________ in dairy cattle is illegal due to being secreted in high amounts in the milk.

Answer 21

cephalosporins

Question 22

Ceftiofur does NOT reach high concentrations in milk, so why do we use Spectramast as treatment for mastitis? How does it work?

Answer 22

we use IMM route of admin which bypassses the barriers to the milk and is placed directly where the infection is.

Question 23

what NSAID is approved for use in cattle?

Answer 23

flunixin meglumine

Question 24

What effect does acute masititis have on the milk withdrawal time?

Answer 24

extends it – longer than label dose, even if you use the label dose. & we wont really know what the WDT will be, so you have to test the milk.