Cattle2- Mastitis

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Cattle2- Mastitis
2015-11-06 18:07:53
vetmed cattle2

vetmed cattle2
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  1. What are the 3 etiologies of mastitis?
    infectious, traumatic, toxic (environment or chemical irritant)
  2. Why is beef cow mastitis less of a problem?
    being on pasture has a diluting effect
  3. Causes of beef cow mastitis. (3)
    confinement housing, calf may be source of infection, S. aureus, Mycoplasma, and environmental pathogens
  4. 3 ways to categorize mastitis.
    clinical vs subclinical, acute vs chronic, toxic vs non-toxic
  5. Describe clinical mastitis.
    visible changes in the milk
  6. Describe sub-clinical mastitis.
    mastitis is present (inflammation of the udder), but there are NO visible changes in the milk
  7. What are some reasons we miss clinical mastitis cases on the farm? (6)
    don't want cows in the hospital, takes longer to milk, owner gets mad, may not be forestripping cows, culling may mask problems, no incentive to report cases
  8. Which is more common: clinical or subclinical mastitis?
  9. How does DHIA define subclinical mastitis?
    >4.0 linear score for the FIRST time in that lactation, based on a composite sample (composite samples are misleading- just because her composite SCC <150k, does not mean one of her quarters isn't over 200K- dilution effect)
  10. How do we define subclinical mastitis?
    any quarter with SCC>200k and the milk looks normal
  11. What's a somatic cell?
    a neutrophil
  12. What are the units of SCC?
    cells/mL of milk
  13. Describe acute vs chronic infection.
    acute is a new/recent infection; chronic are persistent infections
  14. What causes toxic mastitis?
    coliform infections resulting in endotoxemia
  15. What causes non-toxic mastitis?
    often subclinical or contagious pathogens
  16. What are the natural external defenses of the udder? (3)
    healthy skin, keratin plug (forms b/w milkings), healthy teat orifice/sphincter
  17. Specific immune factors in milk, called milk antibody, enhance __________.
  18. __(2)__ make up the majority of SCs in HEALTHY udders, help in recruiting opsonizing Abs and neutrophils.
    Lymphocytes and macrophages
  19. Neutrophils work best when bacteria are coated with ______.
  20. If PMN migration is delayed, we see increased incidences of ___________ and ____________.
    peracute mastitis; overwhelming infections
  21. What are the 5 key functions in successful immune surveillance?
    margination, migration, phagocytosis, respiratory burst, degranulation
  22. What are the udder defenses during the dry period? (3)
    formation of keratin pug, increased leukocyte concentration, elevation of nonspecific antimicrobial factors
  23. High production is positively correlated to...
    genetic susceptibility to mastitis
  24. What is gargot, and how does it form?
    chunky milk; when PMNs enter, they bring other blood factors with them, suhc as fibrinogen---> chunky milk
  25. Possible outcomes of mastitis? (3)
    restoration and regeneration, fibrosis, sclerosis
  26. What components are decreased by the inflammatory response accompanying mastitis? (7)
    lactose, casein, protein, fat, calcium, Ph, potassium [all desirable traits]
  27. What components are increased by the inflammatory response accompanying mastitis? (6)
    Ig, sodium, chloride, SCC, albumin, transferrin [all undesirable traits]
  28. The reservoir for contagious pathogens is the ___________; the reservoir for environmental pathogens is the ___________.
    udder; world
  29. Major environmental pathogens. (4)
    coag-neg. staph (CNS), environmental strep, coliforms, Non-coliform gram neg (Enterobacter spp.)
  30. Major contagious pathogens. (5)
    staph aureus, strep ag, mycoplasma, Corneybacterium bovis (?), strep uberis (?)
  31. Increases in environmental pathogen mastitis generally reflects... (3)
    problem in udder hygiene, parlor practices, and stall management.
  32. Contagious pathogens are generally spread by...
    cow-to-cow in the parlor via poor milking/treatment practices or machinery
  33. Gram negative environmental pathogens. (5)
    E. coli, Klebsiella, Enterobacter, Pasteurella, Pseudomonas
  34. Gram positive environmental pathogens. (2)
    streps, coag-negative staphs
  35. _________ cause toxic mastitis.
    Coliforms (endotoxin)
  36. How can you prevent/ combat coliform mastitis? (2)
    pre-dipped, barrier-type post-dips
  37. Primary sources of E. coli infections. (3)
    bedding, manure, soil; exposure is b/w milkings
  38. How can you prevent E. coli mastitis? (4)
    keep cows clean and dry, avoid overcrowding, germicidal pre-dip, immunization (reduces severity of disease)
  39. What medium does E. coli grow on?
    MacConkey- turns plate pink (lactose fermenter)
  40. What is the primary source of Klebsiella?
    wood shavings (somewhat, manure solids)
  41. How does Klebsiella mastitis respond to treatment?
    poorly- often persistent infections
  42. What are the 2 most important aspects of preventing coag-negative staph mastitis?
    post-dipping (b/c pathogen lives on the skin), dry cow treatment
  43. How do you prevent environmental strep mastitis? (3)
    pre-dip, milking hygiene, clean/dry environment
  44. About 40% of ___________ mastitis infections are eliminated without treatment.
    environmental strep
  45. What 2 pathogens are a red flag to farmers using home-brew treatments?
    yeast and mold
  46. Transmission of contagious pathogens from cow to cow is by... (4)
    poor milking parlor practices, flies, inappropriate nursing, faulty equipment (over-milking)
  47. Contagious pathogen that causes chronic infection and abscesses within the mammary gland; generally considered untreatable.
    Staph aureus
  48. If you do decide to treat Staph aureus, how can you attack it?
    extended intra-mammary antimicrobial therapy
  49. How do you definitively diagnose Strep ag?
    CAMP (+)
  50. What is the hallmark of Strep ag infection?
    high SCC
  51. How do you treat Strep ag?
    easy fix with antimicrobials and good parlor practices
  52. _________ behaves as an environmental and as a contagious pathogen.
    Strep uberis
  53. How do you treat Strep uberis?
    difficult to treat, often becomes chronic
  54. Mycoplasma results from high risk practices, such as... (4)
    home remedies, purchased at sale barn, poor parlor practices, history of respiratory pneumonia
  55. Common clinical signs of Mycoplasma mastitis? (3)
    udder still looks full after milking, milk may look normal, recurring bouts of mastitis
  56. How do you treat Mycoplasma mastitis?
    you don't.... CULL HER
  57. Control measures for contagious mastitis? (7)
    test and cull/isolate, post-dip, back flush b/w each cow, milking hygiene, proper treatment procedures, milk these cows last, pasteurization (before fed to calves)
  58. What are the 3 compartments of mastitis, and the treatments aimed at each?
    • Milk- intra-mammary
    • Tissue/parenchyma- intra-mammary and systemic, long-term
    • Cow- systemic treatment, supportive care
  59. What pathogens are usually in each compartment of mastitis?
    • Milk- Strep ag, other Strep, Coag-neg Staph
    • Tissue/parenchyma- Staph aureus, Strep uberis
    • Cow- coliforms
  60. Direct methods of determining the individual cow SCC. (3)
    direct microscopic cell counts, DHI (electronic cell counts), linear score
  61. Indirect method of determining individual cow SCC. (1)
    CMT (california mastitis test)
  62. CMT is a test that is only used for __________; it should be done at ____________.
    subclinical cows; the beginning of milking
  63. How does electrical conductivity work as a method of identifying subclinical mastitis?
    wit mastitis, blood components enter the udder--> ions are elevated in mastitic milk, making it a better conductor of electricity
  64. What is the number 1 reason you won't culture organisms from 30% of clinical mastitis cases?
    the farmer already treated her
  65. If you think you are dealing with Mycoplasma, you should not ____________ the milk.
  66. Define chronic mastitis.
    2 or more consecutive test dates with SCC score greater than 4 in the current lactation
  67. Define new mastitis case.
    cow with SCC score of greater than 4 for the first time in this lactation
  68. Define a normal SCC.
    cows with consistent SCC score of less than 4 during the current lactation
  69. Diagnosing mastitis at the herd level. (2 methods)
    bulk tank SCC, bulk tank milk culture
  70. What is the best way to measure the prevalence of subclinical mastitis in a herd?
    bulk tank SCC
  71. What is the goal for bulk tank SCC?
    <200k cells/mL
  72. What is the Grade A legal limit for bulk tank SCC?
    <750k cells/mL
  73. Milk quality measures. (4)
    bulk tank milk culture, standard plate count (SPC), preliminary incubation count (PI/PIC), coliform count
  74. Test to determine the total number of bacteria in a milk sample that can grow and form countable colony forming units on a standard methods agar plate.
    SPC (standard plate count)
  75. To determine ______, a sample of milk is incubated for 18hr at 55 degrees followed by the SPC procedure; based on the theory that the normal microflora of the cow will not grow substantially when incubated at this combination, while other organisms will.
    PI (preliminary incubation count)
  76. An estimate of the number of bacteria that can survive laboratory pasteurization.
    LPC (laboratory pasteurization count)- not a state/federally required regulatory test
  77. The legal rules that define standards that pertain to production, transportation, and processing of Grade A milk.
    pasteurized milk ordinance (PMO)
  78. What areas are covered in the standards for Grade A milk? (5)
    milking barn, cow housing area/cow yard, milk house, water supply, methods of sanitation
  79. Risk factors for environmental mastitis. (5)
    bedding, heat/humidity, stress (climate, parturition, overcrowding, handling), injury, feeding practices
  80. Which type of bedding has the highest risk for environmental mastitis?
  81. Hoof and leg hygiene is scored on a scale of...
  82. What is teat end damage associated with? (6)
    3X milking, high milk production, poor udder prep, early attachment, delayed cluster removal, low teat end vacuum at peak milk flow
  83. Teat ends are scored on a scale of...
  84. Parlor practices to prevent contagious mastitis. (4)
    milkers MUST wear gloves, dip, clean the dipper, dry cow txt
  85. What is the first step to treating subclinical mastitis?
    culture so you know your opponent
  86. To be Grade A milk, milk must be cooled to _________ within __________.
    <45 degrees; 2 hrs
  87. What is the main difference b/w grade A and B milk use?
    grade B milk cannot be used as a fluid milk product; it must be used in cultured dairy products
  88. For teat end scoring and hygiene scoring, you want ___% of the herd to be ______.
    >20; 1 and 2s
  89. Pre-dip defends against ___________; post-dip defends against ____________.
    environmental pathogens; contagious pathogens
  90. Systemic drugs that get into the udder. (2)
    penicillin, tetracycline
  91. What kind of drugs do we sue to treat streps?
    beta-lactams (-acillins)
  92. 4 antibiotics we are allowed to use in the dairy cow.
    ceftiofur, penicillin, tetracycline, ampicillin
  93. Drugs that don't make it into the udder when given systemically.
    Cephalosporins (Ceftiofur)