Bovine Top Topic - Mastitis Flashcards
T/F: 30-40% of mastitis milk cultures result in no growth & do not require treatment
TRUE
how is mastitis in cpws characterized?
clinical severeity score - quarter, udder, cow
what are the different clinical severity scores for mastitis in cows?
severeity 1: only the quarter is affected/inflammed, abnormal milk present, severity 2: entire udder demonstrates signs of inflammation (hard, hot udder with swollen mammary lymph nodes, difficult to milk), & severity 3: systemically ill cow, fever, off feed, recumbency in severe cases, high mortality without treatment, & often seen with coliforms due to endotoxemia
what does an environmental pathogen indicate in mastitis?
usually contracted from the bedding
what are some etiologies of environmental causes of mastitis?
coliforms (e. coli, klebsiella, enterobacter, proteus, serratia), streptococcus, & coagulase negative staph
what does a contagious pathogen indicate in mastitis?
staph aureus, strep agalactiae (mostly eradicated), trueperlla pyogenes, & mycoplasma spp
what is the gold standard for diagnosing mastitis?
culture
how is mastitis usually diagnosed In cows?
california mastitis test - will see an increased somatic cell count
what is the normal number of somatic cells present in milk from healthy cows?
under 100,000
what treatment is indicated for mastitis with a severity score of 1 or 2 with no growth on culture?
no treatment - immune system has already cleared the pathogen, so discard milk until it returns to normal
what treatment is indicated for mastitis with a severity score of 1 or 2 that has positive growth on culture for gram-positive bacteria?
intramammary antibiotics
what treatment is indicated for mastitis with a severity score of 1 or 2 that has positive growth on culture for gram-negative bacteria or yeast?
usually no treatment - immune system will clear the pathogen, so discard milk until it returns to normal
what treatment is indicated for mastitis with a severity score of 3?
systemic antibiotics, fluids/electrolytes, flunixin for antipyretic/endotoxic binding effects, nutritional support, & milking out affected quarters as frequently as possible
how is mastitis prevented?
proper milking routines that minimize the spread of disease from cow to cow - pre & post dip cows with antimicrobial agent, minimize cross contamination between cows by milkers, & properly clean/sanitize all parlor equipment after milking
how is bedding management done to prevent mastitis?
remove manure frequently & add clean, dry bedding after milking
what is the benefit of supplying fresh feed for cows after milking?
encourages cows to stand after milking & allows external teat sphincter to close before lying down to help in preventing environmental infections
T/F: you can treat cows with intramammary antibiotics at dry off to help cure chronic infections & add a teat sealant to protect the udder from new infections as well at this time
TRUE
why should you cull cows with mastitis due to s. aureus & mycoplasma?
they don’t respond to antibiotics & infected animals will shed - need to protect the rest of the herd
what are the parameters that are used for bulk tank milk when checking for mastitis?
less than 750,000 somatic cells/ml, less than 10 coliforms/ml, & less than 100,000 bacteria/ml
what is the classic case of contagious mastitis in a cow?
typically see new cases in first 60 days of milk, often subclinical, & decreased milk production due to fibrosis & abscessation in the udder
what is the etiology of contagious mastitis in cows?
staph aureus, mycoplasma, strep agalactiae, & strep dysgalactiae
how is contagious mastitis transmitted?
cow to cow via cross-contact of infected udders - milking equipment or worker’s hands
how is contagious mastitis diagnosed?
CMT - routine bulk tank sampling identifies new clinical cases - string sampling of cows in the parlor to identify affected cows
how is contagious mastitis treated?
sanitation, proper milking procedures, wearing gloves, proper cleaning of equipment, segregate known positive cows & milk them last, cull infected animals due o inability to treat (especially staph aureus due to inconsistent shedding & abscess formation)
T/F: contagious mastitis often causes subclinical mastitis
TRUE
what is the classic case presentation of environmental mastitis?
acute or peracute for coliform, abnormal serosanguinous, watery, or chunky milk, inflamed/hard/hot quarter, & gram negative infections more commonly cause systemic signs & endotoxemia
what is the etiology of environmental mastitis?
e. coli, klebsiella, enterobacter, proteus, coagulase negative stapg, trueperella pyogenes, & corynebacterium bovis
how is environmental mastitis transmitted?
most common is bedding, water, flies/biting insects, & increases with poor teat end health
how is environmental mastitis diagnosed?
milk cultures on clinical cases
how is environemental mastitis treated?
most gram negatives require no treatment if infection limited to the quarter, intramammary antibiotics for coagulase negative staph, yeast self cures with discontinuing of antibiotics, & systemic illness requires injectable antibiotics (ceftiofur & oxytetracycline most common) - vaccination available for coliforms & klebsiella
T/F: coliform mastitis with a clinical severity score of 3 has the highest mortality rate of mastitis cases
TRUE
T/F: coagulase negative staph species are opportunistic normal skin inhabitants that can cause environmental mastitis
TRUE
what is the classic case presentation of gangrenous mastitis?
acute/peracute, high mortality - inflamed quarter that quickly progresses to cold/purple quarter, sloughing of necrotic epidermis on udder, & systemic signs of endotoxemia
what is the etiology of gangrenous mastitis?
staph aureus most common, clostridium perfringens type a, & bacillus cereus rarely
how is gangrenous mastitis transmitted?
contagious or environmental depending on etiology
how is gangrenous mastitis diagnosed?
clinical signs
how is gangrenous mastitis treated?
mastectomy drains the quarter of the abscess - mostly unrewarding, grave prognosis
T/F: in gangrenous mastitis, endotoxemia is caused by gangren not by mastitis infections
TRUE
