Contagious
Chronic mastitis is primarily due to which pathogens: contagious or environmental?
Contagious
What kind of environment do cows need to limit their chance of getting environmental mastitis?
Clean, dry, comfortable
Which contagious pathogen can be completely eradicated from a herd?
Strep agalactiae - only lives within the mammary gland
A healthy cow presents to you because the producer has noticed some clots in her milk. You do a quick PE and everything is within normal limits. How would you classify this cow's mastitis? (Is she clinical, if yes what severity?)
Mild clinical (Abnormal milk but normal cow)
What is a good SCC for a cow?
100,000 cells/ml
What are the three major contagious pathogens? (Bonus: which is most prevalent worldwide?)
Staph aureus - most prevalent
Strep agalactiae
Mycoplasma bovis
What are the 2 major environmental pathogen groups?
Coliforms (E. coli and Klebsiella)
Environmental Streps
What should be the veterinarian's therapy objective when treating a case of mastitis?
Bacteriological cure
On a routine check, a cow was found to have a CMT score of 3. The milk appears normal in all four quarters. This cow would be described as having what kind of mastitis?
Subclinical (milk looks normal)
What are the two most common times that a cow is susceptible to mastitis?
What parameter of mastitis should make you think more contagious pathogens over environmental before you have culture results?
Which form of environmental mastitis will you always treat when clinical?
Environmental Streps (dysgalactiae and uberis)
They are Gram (+) so many products are effective!
What is the only IMM antibiotic that E. coli might be susceptible to?
Ceftiofur (Spectramast)
2 yo Holstein that was cultured at freshening and found to be infected with S. aureus in her LR quarter. One month later on re-culture, the heifer was still positive. A CMT reveals a SCC of 2.7 million cells/mL. (zero in other 3 quarters). The heifer has not been bred. What is the best option for her?
Treat with IMM antibiotics and re-culture at 2 week intervals
(Heifers have greater chance of cure (50%), so always treat!)
Which mastitis pathogen is found in water sources, particularly can be found in drop hoses?
Pseudomonas aeruginosa (fun fact: smells like grape Kool-aid)
What are important control measures for contagious pathogens?
Good milking hygiene
Post-milking teat dip that covers the teat orifice
Single use towels
Back flushing
Etc
What is the best bedding to use in stalls and why?
Sand
Klebsiella likes wood shavings
Environmental Streps love straw
E. coli is in manure solids
Why should banamine be a part of the protocol when treating a cow for mastitis?
Combats the endotoxins released when killing bacteria (like TNF alpha)
A cow presents with clots in her milk, a SCC of 2.7 million, decreased rumen contractions, a pulse of 108 and is 5-6% dehydrated. What is the most important treatment that this cow needs?
IV fluids - most important thing for the severe clinical mastitis cow! (Rumen is weak, so she needs them IV)
Which organism typically shows some form of hemolysis on culture?
S. aureus
What is the most common pathogen in herds that don't teat dip post-milking?
Corynebacterium bovis
Which environmental bacteria is associated with contaminated teat dip, and colonies are orange on blood agar?
Serratia
Describe how treatments differs between the three contagious pathogens.
S. aureus - Tx depends on age, value, health of animal; always treat heifers
S. agalactiae - always treat because eradication possible
M. bovis - no effective treatment, most likely cull
Okay not really a case but tell me the CMT cores and associated SCC. :)
Trace - 300,000
1 - 900,000
2 - 2.7 million
3 - 8.1 million
What is the only other bacteria, besides S. aureus, that has been seen to cause gangrene mastitis?
Bacillus