Exam 3 - Mastitis Flashcards
T/F: mastitis results in a high economic impact in the dairy industry & is a very important disease
true
what are the clinical manifestations seen in mastitis? what about the nature of the pathogen?
subclinical or clinical (mild, moderate, or severe)
contagious or environmental
what are the legal requirements for bulk tank measurements in regards to mastitis?
bulk tank somatic cell count - <750,000 cells/mL
bulk tank bacteria - <100,000 CFU/mL
what are the 4 contagious pathogens commonly implicated in food animal mastitis?
- staphylococcus aureus
- streptococcus agalactiae
- mycoplasma
- corynebacterium bovis
what is the most prevalent contagious pathogen causing mastitis in cows? what are the clinical signs associated with it?
staphylococcus aureus - most prevalent & often subclinical cases!
chronic infections with clinical flare-ups (occasional severe cases) with fluctuating SCC & bacterial counts
T/F: in animals with streptococcus agalactiae mastitis animals, they are often subclinical & are unlikely to become systemic
true
what are the clinical signs associated with streptococcus agalactiae mastitis?
persistently high SCC & bacterial counts
______ _________ is an obligate pathogen of the bovine udder
streptococcus agalactiae
what are the clinical signs associated with mycoplasma mastitis? what do you do with these cows?
multiple quarters are affected, arthritis, respiratory disease, decreased milk production with high SCC
transfer them to Jesus
what are the economic impacts seen from mastitis?
decreased milk production/quality
penalties
mortality & replacement costs
milk discard
drugs & veterinary costs
what contagious agent of mastitis is a primary streak canal colonizer?
corynebacterium bovis
which contagious agent of mastitis is often used as an indicator of teat dip efficacy?
corynebacterium bovis
what are the clinical signs associated with corynebacterium bovis mastitis?
mild increases in SCC
what are your gram negative environmental pathogens that cause mastitis in food animals?
e. coli, klebsiella, enterobacter spp., citrobacter sp.
what are your gram positive environmental pathogens that cause mastitis in food animals?
streptococcus uberis, streptococcus dysgalactiae, & enterococcus
are the majority of environmental mastitis cases clinical or subclinical?
majority are subclinical! most are self-limiting!
occasional chronics with klebsiella, serratia, & streptococcus uberis
when is the highest incidence seen of environmental agents causing mastitis in food animals?
late dry/early lactation!
what animals are typically affected by severe systemic disease from mastitis? what agents are involved?
periparturient animals
gram negative pathogens!
what clinical signs are seen in animals with systemic disease due to severe mastitis from environmental pathogens?
endotoxemia/sepsis, fever, tachycardia, decreased rumen motility, scleral injection, & dehydration
what hematological/biochemical abnormalities are seen in animals with systemic disease due to severe clinical mastitis from environmental pathogens?
neutropenia
hypocalcemia, hypokalemia, hyperglycemia, mild azotemia, & transient hypophosphatemia
how are environmental pathogens causing mastitis transmitted? what are the reservoirs?
between milkings - iatrogenic!
bedding (sawdust - klelbsiella, straw bedding - environmental streptococci), fecal material, stagnant water (pseudomonas)
what are some common staph spp. that can cause mastitis?
s. chromogenes, s. hyicus, s. warneri, s. epidermis, etc
what are some uncommon pathogens that can cause mastitis?
pseudomonas aeruginosa, arcaonbacter pyogenes, nocardia, mycoplasma bovis, mycobacterium sp, etc
what are some physical changes that may be seen in a food animal with mastitis?
inflammation - pain, heat, swelling, redness
altered secretion, dripping milk, gangrene, & emphysema
what are some reasons we may see increased somatic cell counts?
infection, inflammation, trauma, & low production
what are some ways we are able to determine SCC of milk?
direct microscopy, california mastitis test, wisconsin mastitis test, & electronic counters
what should be improved if you diagnose a cow with mastitis from corynebacterium bovis?
improve teat dipping efficacy in the program
______ versus ______ may determine treatment plans for mastitis due to withdrawal periods
lactating
non-lactating
what treatment is used for mastitis caused by s. aureus?
therapeutic cessation of lactation
strict segregation/culling/therapeutic cessation of lactation
unlikely to respond well to treatment during lactation - extended intramammary therapy may work
what treatment is used for mastitis caused by s. agalactiae?
seen usually in the 1st 3rd to half of lactation - very responsive in the dry period - treat when they are not lactating!
what is the treatment used for local disease seen in clinical mastitis?
frequent milk out & intramammary antibiotics
what is dry cow therapy? what is the purpose of it?
long-acting antibiotics & teat sealers
prevent new infections from occurring & treat existing infections
what treatment is used for animals with severe disease from clinical mastitis?
focus on countering septicemia & endotoxemia!!
fluid therapy, electrolytes, & correct acid-base abnormalities
antibiotics - local & systemic
what salvage procedures are used for treating clinical mastitis?
teat amputation
chemical cessation of lactation
what control measures are used for preventing mastitis caused by contagious pathogens?
teat dips
dry cow therapy
decrease potential for transmission
cull the chronics
don’t purchase older cows
pre-purchase screening can be done!
what control measures are used for preventing mastitis caused by environmental pathogens?
decrease environmental contaminations
micromineral nutrition
decrease use of water in parlor
keep cows standing for 30 minutes after milking
vaccinate
teat dips
how is milk cultured when testing for mastitis?
10-50 uL of fresh or thawed milk
spread evenly across media
incubate at 37°C for 24-48 hours
what should be considered prior to pursuing treatment for subclinical disease caused by mastitis?
cost vs. benefit
untreated cure rate vs. treated cure rate
T/F: for environmental pathogens causing mastitis, gram positive organisms will potentially have a response to teat dips while gram negatives do not
true
T/F: for local disease caused by clinical mastitis, it was recommended to milk them out frequently, but no overall benefit was found in the treatment of clinical mastitis caused by environmental pathogens
true
what are the goals of dry cow therapy?
prevent new infections during the early dry period
treat existing infections at dry off!!
external teat sealer - stronghold
internal teat sealer - orbeseal
what iv fluid therapy should be started for a severely dehydrated cow from clinical mastitis?
40 ml/kg for the 1st hour
10-20 ml/kg/hr for the subsequent hours
what are some local intramammary antibiotics used for treating local disease from mastitis?
cephapirin & amoximast
what are some systemic antibiotics used for treating mastitis?
ceftiofur & oxytetracycline - treat sepsis!!
what is the NMC 10 point plan for control of mastitis?
- establish goals for udder health
- proper milking procedures
- maintenance of a clean environment
- proper maintenance & use of milking equipment
- appropriate treatment of clinical mastitis during lactation
- effective dry cow management
- maintenance of biosecurity for contagious pathogens & culling of chronically infected cows
- good record keeping
- regular monitoring of udder health status
- periodic review of mastitis control program
how do you decrease the potential of transmission of contagious pathogens causing mastitis in cows?
look at milking order!!! sickos go last
milking time hygiene
treatment of strep agalactiae
what bedding options do you have for decreasing spread of environmental pathogens causing mastitis in cows?
sand, mattresses, & gyspeum
what are your high risk groups for subclinical mastitis?
high SCC cows
older cows
what should make up bulk tank surveillance for mastitis?
somatic cell counts
pre-pasteurization loop plate count
post-pasteurization loop plate count
contagious mastitis pathogen count
what agent causes blue bag in sheep?
pasteurella spp!!! acute gangrenous mastitis - happens in periparturient & post-weaning moms
old path notes list s. aureus/mannheimia
what kind of mastitis is caused by pastuerella in sheep?
often acute gangrenous mastitis
what contagious pathogens cause mastitis in goats?
CAEV - retroviral mastitis
mycoplasma spp.
s. aureus - common, gangrenous mastitis!!!
strep. zooepidemicus
T/F: in goats, their normal SCC is higher than cattle
true
what are some clinical signs of mastitis in pigs?
crushed piglets & piglet illthrift
what pigs are commonly affected by mastitis?
periparturient sows
what environmental pathogen is known to cause mastitis in pigs?
streptococcus spp
what are the most common pathogens causing mastitis in beef cattle?
staphylococcus aureus & environmental pathogens
what are the consequences of mastitis in beef cattle?
decreased weaning weights
how is mastitis detected in beef cattle?
physical exam
CMT
milk culture
what is a negative CMT test for a cow? what about a goat?
cow - 0-200,000 SCC cells/mL
goat - 0-480,000 SCC cells/mL
