Udder Health Flashcards
1
Q
Can bacteria spread through the udder quarters?
A
- NO
- Bacteria must enter through the streak canal of each quarter
- Exception - Mycoplasma organisms
2
Q
What is required for mastitis to occur?
A
- Bacteria
- Either Animal susceptibility or Environmental/management issues
3
Q
What are the common pathogens that cause mastitis?
A
- Contagious
- Staph aureus
- Mycoplasma bovis
- Strep agalactiae - very rare in the US
- Environmental
-
Coliforms (E. coli, Klebsiella, Enterobacter sp. )
- Up to 40% of cases, and 25% of cows in well-managed herds are dx with coliform mastitis anually
- Environmental streps: Strep uberis, Strep dysgalactiae
- Other gram negative - Serratia, Proteus, Raoultella
-
clinical mastitis due to gram- is inbersly related to bulk tank somatic cell count
- BTSCC⇣ = G-⇡
-
clinical mastitis due to gram- is inbersly related to bulk tank somatic cell count
-
Coliforms (E. coli, Klebsiella, Enterobacter sp. )
4
Q
Why are cases of mastitis moving from contagious to environmental causes?
A
- Due to industry’s adoption of mastitis control program
- Post milk teat disinfection
- Universal dry-cow therapy
- Treatment SOP for clinical cases
- Routine/regular milking machine maintenance
- Culling chronic mastitis cows
5
Q
How do infections occur with contagious vs environmental pathogens?
A
- Contagious:
- able to colonize and live within the udder
- Infection occurs during the milking process
- Environmental:
- Are eliminated rapidly once inside the udder
- Infection occurs between milking
- can occur during with dirty udders / poor machine function
6
Q
How is environmental mastitis managed?
A
- Proper human milking procedures/training/monitoring
- Bedding
- Manure
- Environmental moisture
- Stall design
- Animal density
7
Q
What are the signs of clinical mastitis?
A
- Abnormal milk (flakes, clots, etc)
- Abnormal secretions
- Quarter(s) that are:
- red, swollen, or painful
- Fever
- Anorexia
- Lethargy
- Rumen stasis
8
Q
How is clinical mastitis severity scored? why?
A
- Used to monitor how quickly/slowly milkers are recognizing mastitis
- If 20% or more of the mastitis cases =score 3, the observational intensity or case definitions need to be re-visited
9
Q
How is a subclinical mastitis identified?
A
- California mastitis test (CMT)
- negative = 100,000
- Trace = 300,000
- 1 = 900,000
- 2 = 2.7mil
- 3 = 8.1mil
- Electrolytic conductivity
- in line or handheld (MasTek)
- Resistance of milk to electric current
- Mastitis: Lactose and K decrease, Na and Cl increase
- Somatic Cell Count
- Raw SCC >200,000/ml = infection
- Linear score > 4.0-4.2 = infection
10
Q
How is Bacterial load at milking reduced?
A
- Pre-dip - control environmental mastitis
- reduces bacteria load on the teat at time of milking
- Post-dip - control of contagious mastitis
- Removes milk film (lessens nutrients available for bacterial growth & reduces the number of bacteria that can colonize the teat skin between milking)
- Doesn’t last long enough between milkings to assist with environmental mastitis
11
Q
What teat dips are out there?
A
- Good universal: 1% iodine with 10% emollients (glycerin, etc)
- Chlorine
- Acidified sodium chlorite
- sodium hypochlorite
- chlorhexidine
- Hydrogen peroxide
12
Q
What vaccines exist for mastitis?
A
- Gram Negative core vaccines:
- E. coli - J5, Mastiguard, JVac
- Klebsiella - Klebvax, Vaccon
- labeled for 2-3 doses per year
- Anticipated Effectiveness:
- reduces severity of gram negative infections
- Likely does not reduce infection risk
- Staph Aureus - Lysigin
- current research - SA vax increases spontaneous cure rates
13
Q
What are the challenges for Mastitis vaccines?
A
- Milk dilution of immune cells
- Antibody concentration in milk is much lower than serum
- Fat and casein reduce effectiveness of immune cells
- Milk is an excellent growth media for bacteria
- SA microabscesses, fibrin deposition, intracellular life
14
Q
When should mastitis vaccinations be used?
A
In herds that are performing the 5 step prevention program ad are concentrating on environmental management
15
Q
What is a teat sealant?
A
- Used to prevent bacteria from entering the streak canal
- Applied when animals go dry to prevent dry cow/fresh cow mastitis
- Types:
- External - silicone/latex based, non-antibiotic
- Internal - bismuth based, non-antibiotic
16
Q
Should teat sealant and/or antibiotics be used at dry off?
A
- internal teat sealants are economically worthwhile
- can estimate advantage/disadvantage, cost of mastitis case (production loss, treatment, saleable milk loss, increase culling vs sealant cost)
- Blanket Antibiotic treatment is economically worthwhile
- also aids in curing infections existing at dryof
- Select Antibiotic treatment:
- cows with no count >200,000 in the last 3 months in low SCC herds do not require antibiotic treatments at dryoff
17
Q
What are the economic costs of mastitis in dairy cattle?
A
- Increased amount of non-saleable milk
- Decreased milk production
- decreases amount of saleable milk
- Decreased milk quality
- Producer doesn’t receive quality bonus
- Reduced shelf-life and cheese yield
- Increased treatments
- Increased culling
18
Q
What types of milking systems are used in the US?
A
- 78% of cows milked in parlors
- Tandem parlor
- Herringbone parlor
- Parallel parlor
- Parabone parlor
- Rotary parlor
- Robotic
- $$$
19
Q
What is the Bulk Tank?
A
- Where the milk is collected to be transported ot eh milk company
- Where samples for milk cultures can be collected
- Milk after the first 6 milkings after calving and not on antibiotics, anti-inflammatories, etc will be collected here
20
Q
How is surveillance for antimicrobial residues in milk done?
A
- Each arriving truckload of milk at the plant must be tested for the presence of at least 4 of 6 speific Beta-lactam drugs
- Penifillin
- Ampicillin
- Amoxicillin
- Cloxacillin
- Cephapirin
- Ceftiofur
- Random samples are also tested for other antibiotics, non-steroidal inflammatory drugs and antihistamines
21
Q
What happens to the producer when there are antimicrobials found in their milk?
A
- Grade A permit suspension
- Milk sales on hold until further notice
- Milk must be disposed of in a manner that removes it from the human and animal food chain
- Producer is liable for value of all milk on the contaminated load
22
Q
How does a producer get reinstated after having their milk test positive for antimicrobials?
A
Representative milk samples tested and not positive for drug residues
23
Q
What is the production cycle for a dairy cow?
A
24
Q
What is the Iceberg principle with mastitis
A
For every clinical mastitis case there are ~15-40 subclinical cases
25
Why is oxytocin important in dairy cattle?
26
Do beef cattle get mastitis?
* Usually isolated events
* Staph aureus common
* fly transfer, pasture
* Trueperella pyogenes - common secondary invader
* Mycoplasma sp - rare
* more associated with multiple animals affected
* Common to see calf pneumonia/otitis/joint infections in conjunction
27
How is beef cattle mastitis treated?
* Intramammary treatment not effective
* Injectable antibiotics not effective
* Treatment = Teat amputation
* bottom half of the teat
* rapid clinical improvement
28
What is Udder cleft dermatitis?
* “necrotic dermatitis”
* Malodorous
* weeping wound
* Udder attachment to body wall
* Caused by mites in some cases
29
How is Udder cleft dermatitis treated?
* Clean
* Topical antiseptic
* Miticide
* Eprinex
30
What is Herpes mammilitis?
* Cause: Bovine Herpesvirus II
* Vesicles form and rapidly rupture
* may be a few to the entire teat
* Almost always 1st lactation animals
* Histo and virus isolation to dx
31
How is Herpes mammillitis treated?
* Milk last
* teat dips with emollients
32
What is *Mycoplasma wenyonii* and how does it affect dairy cattle?
* RBC parasite
* Symptoms:
* Bilateral rear limb edema +/-
* Teat and udder edema
* Not associated with calving
* Usually resoles in 6-8 days
* injectable oxytet - speeds recovery
33
How is the severity of mastitis graded?
* Score 1 - abnormal milk only
* Score 2 - abnormal milk & red/swollen quarter
* Score 3 - Abnormal milk, red/swollen quarter, & systemic signs (fever, rumen stasis, lethargy, severe production loss)
34
What are the treatment options for mastitis?
* Not culture based
* clinical signs ⇢ IMM treatment
* Culture based
* clinical signs ⇢ IMM treatment ⇢ Culture ⇢ reassess treatment
* clinical signs ⇢ culture ⇢ maybe IMM treatment
35
What are the considerations when choosing an IMM treatment?
* Target organism
* Number of treatment
* Milk withhold
* slaughter withhold
* Cost usually NOT a consideration
36
What are the benefits of using a non-culture based approach to treating mastitis?
* Increases probability of bacterial cure
* Decreases probability of chronicity
* Rapid return to saleable milk
37
Why would one not use the culture based approach to treating mastitis?
* Large percentage of gram negative infections will self-cure regardless of treatment
* Concentration on reducing antimicrobial use
38
How does the culture based therapy work? when do you use antimicrobials?
* Immediate antimicrobial treatment:
* Intramammary antibiotics while waiting for culture results
* Delayed antimicrobial treatment - wait for results
* Results:
* No growth - stop treatment/ no treatment
* Gram Neg - stop treatment/no treatment or change to IMM with gram neg spectrum
* Gram Pos CNS/Streps - continue IMM, narrow spectrum antibiotics for 1-3 days as per label.
* Staff aureus - consider history
* treat - early lactation
* do not treat - mid lactation
* Dry early - late lactation
* Cull - chronic cows
39
What is the treatment for severe mastitis?
* Fluids (if IV practical) 5-10 gallons PO 2-3x / day
* Fluid option - 1L hypertonic saline IV followed by PO water
* Anti-inflammatory - flunixin / Dexamethasone
* Systemic antibiotics:
* no labeled antibiotic for systemic mastitis
* Excenel at labeled dose, route frequency (ELDU)
* IMM antibiotics - collect sterile sample first!
* More likely gram negative
* Spectramast or Polymast
40
How can a vet tell if the cause of mastitis is environmentally based?
* Many time see an increase in BTSCC 7-10 days later
* Once resolved, BTSCC will decrease within a day or two
41
How can a vet tell if the cause of mastitis is contagious?
* Slow increase in BTSCC over weeks to months
* especially staph aureus
* Sudden increase in BTSCC or clinical mastitis due to contagious pathogens is rare
42
How is a sterile milk sample collected?
* Use a new set of gloves for each cow
* remove the first 2-3 squirts from each teat onto the ground
* Pre-dip each teat, leave for 30sec
* Dry teats with individual paper towel
* Scrub each teat end with an alcohol soaked cotton ball
* furthest teat first, closer last
* alcohol swab should show no signs of dirt
* Sample closest teat first, farthest last
* 2-4 squirts
* do NOT hold the vial directly under the udder. Hold it horizontally and direct the milk flow into the vial
