Herd Mastitis Flashcards
what are the main bacteria that cause mastitis
staphylococcus aureus
coagulase negative staphylococci
streptococcus agalactiae
streptococcus dysgalactiae
E coli
Klebsiella
truepurella pyogens
mycoplasma bovis
corynebacterium bovis
what is the definition of major pathogens
serious reaction
high SCC
milk drop
clinical signs of diseease
even death of cow
what are examples of major pathogens
streptococcus agalactiae
streptococcus dysgalactiae
streptococcus uberis
E coli
staphylococcus aureus
what is the definition of minor pathogens
mild immune response
no or slight increase of SCC
slight decrease or perhaps increase in production and may cause clinical signs of disease
what are examples of minor pathogens
corynebacterium bovis
staphylococcus epidermidis
coagulase-negative staphylococcus (CNS)
micrococci
what is contagious clinical mastitis
infection transmitted from cow to cow by milking machine and milkers (ex hands)
cow to cow
milker’s hands, milking machine
what is environmental clinical mastitis
infection acquired from the cow’s environment
what are examples of contagious pathogens
staphylococcus aureus
streptococcus agalactiae
mycoplasma spp
CNS
streptococcus uberis
streptococcus dysgalactiae
what are examples of environmental pathogens
e coli
klebsiella spp
CNS
streptococcus dysgalactiae
streptococcus uberis
yeasts
what can contribute to contagious mastitis
damaged teat ends susceptible, milking machine malfunction can contribute
how does staphylococcus aureus spread and where does it go
Mammary gland of infected cows (bovine skin, milkers hands, flies and barn environment)
Adhere to the endothelial lining of the teat and udder cisterns
- High up in the udder
Easily spread in-parlour
what does acute/peracute infection staphylococcus aureus cause
acute/peracute infection
- severe systemic reaction
- recently post calving (NEB)
- gangrene
what does chronic staphylococcus aureus cause
Increased prevalence: older cows; late in the LAC
Moderate inflammatory reaction
Missed or few clots
Tissue atrophy and abscessation
Notoriously difficult to treat and control!
why is staphylococcus aureus difficult to treat and control
1st case of infection the cow is treatable with a cure rate of about ~70% with a prolonged antibiotic therapy
Recurrent cases cure rates are around ~20%
Cows appear to clear up and then within 7 days they reappear with a recurrent infection —> typical pattern because it hides so high up in the udder antibiotic penetration can be poor
what does Streptococcus agalactiae cause
subclinical infections
what are the main features of Streptococcus agalactiae mastitis
Highly contagious
Udder (occasionally teat canal and teat skin when the surface is cracked)
Subclinical infections
- High SCC cows
Easy to isolate on culture (infected quarter — up to 10^8 bacteria/ml):
- Cow
- Bulk tank
how does streptococcus agalactiae respond to antimicrobial therapy
‘blitz’ therapy
all quarters of infected cow (whole herd/selected animals)
good response
what are the main features of mycoplasma spp
highly contagious
most common spp is m. bovis
what might mycoplasma be associated with
resp disease
arthritis
why is biosecurity important in mycoplasma spp
importation of cattle into a herd
not common in UK but in USA and Europe
is there a good response to treatment of mycoplasma
poor response
how do we see and diagnose contagious mastitis during lactation
Recurrent clinical cases
Treatment failures
High SCC but not necessarily high clinical numbers
Climbing BTSCC (10% rise?)
- Insidious contagious problem
Collecting milk samples — but hard to culture
Repeat sampling may be necessary — intermittent shedding
Cow history and clinical cure rates, use herd test trends
>10% of herd >200,000 cells at consecutive tests, high new IMI rate for heifers entering the herd
how do we manage and treat contagious mastitis
Find clinical early, remove from supply, milk last — reduce infection spread
- She can infect a bunch of other cows
- Key is to identify early so you can separate them
- Best chance of cure when identified early and given extended course of antibiotic therapy
- Time dependent bug so its how long the bugs are exposed to antibiotics that give the best results
Routine looking for clinical
Extended lactational cow therapy best chance of cure
Dry cows off — long course of antibiotic may increase chance of cure
- 30-50 days of cover
how do we prevent contagious mastitis
Reduced infected population — cull cows, treat cows
Teat dip/spray
Milking machine maintenance
Milking routine
- Sterile and hygienic
Gloves
- Cracked hands harbour bacteria
when are environmental pathogens typically picked up
may pick up in the dry period (5% no keratin plug)
damaged teat ends susceptibe
what are clinical outbreaks of strep dysgalactiae
poor hygiene
increase of teat lesions
milking machine faults
what is strep dysgalactiae infection common in
heifers, heifer calves, dry cows
what is strep dysgalactiae associated with
summer mastitis complex
where is streptococcus uberis found in the environment
ubiquitous
when is streptococcus uberis common
subclinical infections in the dry period
how is treatment of streptococcus uberis
difficult
In vitro sensitive to many antibiotics
In vivo poor response
- Capsule formation
- Strains
- Intracellular
- Mammary lymph node
where is coagulase-negative staphylococci (CNS) found in
teat skin, teat end and teat canal
what level of pathogenicity is coagulase-negative staphylococci (CNS) considered
low
what lactation is coagulase-negative staphylococci (CNS) infection associated with
1st lactation animals with higher rate of infection
at what point in the cycle is CNS infection common
highest infection immediately after calving and late lactation
what increases the risk for E coli infection
Early lactation (dry period; after calving)
Poor hygiene
Immunosuppression (metabolic diseases)
Extremely low SCC herds
what does acute and severe clinical mastitis with E coli infection lead to
Rapid multiplication —> endotoxin (LPS) —>
- High/subnormal temp
- Depression
- Anorexia
- Rumen stasis
- Diarrhea
- Recumbence
- Death
what is klebsiella spp infection associated with and how is it spread
Contaminated/poor quality sawdust bedding
Fecal shedding
what does klebsiella spp do
Invade deeply into the gland and damage secretory capacity
does klebsiella spp have an endotoxin
yes
how should severe klebsiella infections be treated as
severe clinical cases approach as E coli mastitis
may cause chronic infections
what are sources of pseudomonas spp
Contaminated water, udder wash, teat-dip and dry cow tubes
what are the signs of pseudomonas spp
Clinical mastitis — often with gangrene; death
how is the treatment response of pseudomonas spp
poor antibiotic response
Usually culled because they are untreatable
what is arcanobacter pyogenes (trueperella pyogenes) associated with
Dry cow mastitis (‘summer mastitis’)
how is arcanobacter pyogenes (trueperella pyogenes) transmitted
Files, contact with contaminated environment
what is the route of arcanobacter pyogenes (trueperella pyogenes)
Damaged teat skin or canal
what are the signs of arcanobacter pyogenes (trueperella pyogenes)
Quarter:
- Swollen, hot, painful, thick purulent secretion
Cow:
- Often sick/pyrexic, may lose the quarter and may abort
what other bacteria may be present with Arcanobacter pyogenes (Trueperella pyogenes)
+/- Peptococcus indolicus
+/- Streptococcus dysgalactiae
where are yeasts found
straw or other bedding wet and/or mouldy
what are risks for yeast infections
Cows lying out of cubicles (free-stalls)
Failure to dry teats after wash before milking (contaminated and non-sanitized water)
how are yeasts treated
difficult to treat
not responsive to antibiotics
how do we see and diagnose environmental mastitis during lactation
Milk sampling
High BTSCC in early lactation and high % clinical
- Picking them up in the dry period and presenting with them when they start lactating
Large numbers of cows coming in with mastitis — easy to cure
- Strep uberis can be frustrating
- Compared to Staph spp
Herd test trends
how do we manage and treat environmental mastitis
Dry cow therapy!
- Treat existing infection and PREVENT NEW INFECTION
Teat sealant or combo therapy
- Inert or one with an antibiotic
Teat spray/dip
Improve hygiene in the environment
Udder prep for milking
Udder prep for DCT and LCT
Minimize milk dripping pre-calving
- Open teat ends and more susceptible
Nutrition (feces)
- Scraping of manure so they are not sitting in feces
- Runny feces difficult to clean
how do we prevent environmental mastitis
Hygiene at dry off
Good dry cow management
Feed pad/shed/race hygiene
Udder hygiene
Teat spray/dip
Teat end condition — emollients (create a proper seal)
