Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
97 Cards in this Set
- Front
- Back
What is mastitis?
|
Inflammation of the milk secreting tissues of the mammary gland caused by microbial infection of 1 or more quarters
|
|
Is mastitis a dz of humans?
|
Yes
|
|
What economic losses are caused by mastitis?
|
Decreased milk production
Milk dumped due to treatment Veterinary and drug costs Labor costs Culling and death losses Lost quality premiums |
|
Bacteria that cause mastitis enter from where?
|
generally enter through the teat canal
|
|
What are the risk factors for mastitis?
|
-cow characteristics
-milking procedure -milking machine -environment -infectious organisms |
|
What is the first line of defense against bacteria in the mammary gland?
|
Teat canal
-epithelium -keratin plug -teat sphincter -length/width of teat canal -leucocytes in fore milk |
|
After milking, the teat canal can remain open for 2 hours, what should you do with the cow during that time?
|
have her stand
|
|
What somatic cells are found in the healthy udder?
The mastitic udder? |
Macrophages in healthy udder
Neutrophils in mastitic udder |
|
What is the normal somatic cell count?
|
Normal somatic cell count < 100,000 cells/ml
|
|
Why do neutrophils struggle to exist in the mammary gland?
|
-Milk has lactose NOT glucose
-No energy source for PMNs -Deficiency of opsonins and complement in milk -Casein coats the outside of the neutrophil -Loss of PMN pseudopods due to ingestion of fat -Decrease in supply of hydrolytic enzymes within the PMN following ingestion of fat and casein |
|
Immunoglobulins provide what defense to the udder?
|
-enables phagocytosis
-can prevent adherence of bacteria to epithelial cells |
|
What role does lactoferrin play?
|
Prevents multiplication of iron-dependent bacteria
|
|
Which cytokines are defense mechanisms for the udder?
|
Interleukins
Interferons Tissue Necrosis Factor Colony Stimulating Factors |
|
Why do most new cases of mastitis develop at or near the time of calving?
|
Lowered defenses
High circulating cortisol levels!! Neutrophil function is depressed Macrophages are not as efficient at phagocytosis Milk leaking Concurrent illness LDA, metritis Coliforms in calving area Previous Staph |
|
What are the signs of clinical mastitis?
|
Signs of infection
Udder shows signs of inflammation Milk is abnormal Flecks, gargot (clots), off color, bloody |
|
What is a sign of subclinical mastitis?
|
No evidence of abnormality except milk positive on special tests
|
|
How does mastitis decrease milk production?
|
Decreases milk production by causing tissue damage, reduced lactose production and scar tissue formation in the udder
|
|
How does mastitis affect milk composition/quality?
|
Increasing somatic cell count
Polymorphonuclear neutrophils Decreasing lactose, casein, and fat production, Increasing blood components such as Na, K, Cl, bicarbonate, IgG and serum albumin. Bacteria, blood cells and enzymes Proteolysis Lipolysis and globule breakdown Off flavors |
|
What does a proper examination of the mammary gland include?
|
You have to visually examine it AND palpate the entire gland and associated lymph nodes
|
|
What are the cardinal signs of inflammation of the mammary gland?
|
Rubor
Calor Tumor Dolar Loss of function |
|
What changes do you look for when visually examinin the udder?
|
Loss of symmetry
External lesions |
|
When palpating the udder, what changes do you look for?
|
Fibrosis
Enlarged lymph-nodes Abscess Hot, painful, swollen |
|
Macroscopic changes in milk secretion include what?
|
Flakes
Clots Gargot Clumps Watery Bloody |
|
What is gargot?
|
Flakes of fibrin, cells and calcium produce chunks
|
|
What stall side test can be used to check for mastitis?
|
CMT-checks for subclinical mastitis
|
|
What other dx test help monitor the herd for mastitis?
|
DHIA
SCC Milk Cultures Ultrasound! Abscesses Nonfunctional quarters |
|
What is the basis for the CMT?
|
Cow side test
Alkyl arylsulfonate and bromcresol purple Lysis cells and polymerizes DNA Gel is formed by the DNA More gel = more nucleated cells. |
|
What conditions can affect the results of a CMT?
|
Colostrum
Late lactation (at dry off time) Illness leading to abrupt decrease in milk First strippings of milk from teat Residual milk Trauma to udder |
|
What 2 types of milk samples can be collected for bacteriology testing?
|
-individual
-bulk tank |
|
When do you perform an individual bacteriology collection/test
|
used to screen herd for infected cows
|
|
When do you perform a bulk tank bacteriology test?
|
Used to screen or monitor herd for contagious mastitis (Strep ag, Staph aureus, Mycoplasma)
|
|
90% of mastitis is caused by a contagious spread or by infection from the environment?
|
Contagious, animal to animal
|
|
By what methods is contagious mastitis spread?
|
Is spread from cow to cow, primarily during milking by milk-contaminated fomites at milking, sponge, milker's hands, milking machine
|
|
What are the BIG 2 organisms that are responsible for contagious mastitis?
|
Staphylococcus aureus, Streptococcus agalactia
|
|
What is meant by acute mastitis?
|
Rapid and severe onset
High temperature Serious condition |
|
What is meant by acute gangrenous mastitis?
|
Same onset as acute, but then mammary gland becomes cold and cow rapidly deteriorates
|
|
What is chronic mastitis?
|
Persistent subclinical form
|
|
Can chronic mastitis still affect production and become a problem?
|
yes
Bulk tank SCC >250,000 >15% of cows on DHIA have a linear score >4.5 >2% new clinical cases per month |
|
What are the characteristics of Staph aureus?
|
Facultative anaerobic
Gram positive cocci Grape-like clusters “Golden” appearance Coagulase positive |
|
Staph aureus is the most important cause of mastitis, where does it live?
|
On the skin
(is drug resistant, highly invasive and host adapted) |
|
Gangrenous mastitis from S aureus is more common in which type of cow?
|
First calf heifer
|
|
What is the pathogenesis of S aureus?
|
Colonize teat skin and enter through sphincter
Early lactation Gangrenous mastitis in cows, goats sheep Chronic infections are the rule |
|
What is the end result of a S aureus infection?
|
Invades the milk producing tissues
Attaches to the alveoli tissue Abscesses form |
|
What are the clinical finding of a S aureus infection?
|
Initial systemic response
Subsequent relapses are mild Milk is thin with yellow flakes/clumps |
|
What is the number 1 way that S aureus is spread?
|
man, milking machine
|
|
How can Staph infections be prevented?
|
Pre & post milking teat dipping
Milkers wear gloves Separate paper towel for each udder Milk infected cows last Dry cow treat all cows Cull cows with long standing infections (chronic) Screen replacements (home & purchase animals) |
|
What are the characteristics of Streptococcus agalactia?
|
-beta hemolytic (wide area of hemolysis on blood agar)
Gram positive Predominatly facultative anaerobic |
|
Where does S agalactia live?
|
Obligate intramammary
Short life outside the gland |
|
Which age of cows are more susceptible to S agalactia?
|
older
|
|
What is the pathogeneis of S agalactia?
|
Spread is cow to cow or fomite
Enters through teat sphincter Colonizes teat skin Inflammation occurs in 4-5 days Fibrin clots can block ducts |
|
What are the sources of S agalactia infection?
|
Major source is the infected cow
Injected into udder during milking Contaminated floors and stalls Newly purchased cows Heifer calves suckling penmates Milking personnel as carriers |
|
Generally, does S agalactia produce clinical or subclinical mastitis?
|
generally non-clinical, but produces high somatic cell count (SCC) and reduces milk production.
|
|
What are the clinical findings of S agalactia infection?
|
Initially fever, depression,off feed
Subsequently mild episodes Milk is thin with white flakes and clumps |
|
Can S agalactia be treated?
|
Susceptible to penicillin
|
|
How can you prevent S agalactia infections?
|
Pre & post milking teat dipping
Separate paper towel Milk infected cows last Dry cow treat all cows Screen replacements |
|
How do you provide protection against S aureus to the herd?
|
Culture and treat all positive cases
Repeat in 30 days Institute contagious mastitis control program |
|
What makes Mycoplasma bovis difficult to deal with?
|
Between a bacteria and a virus
No cell wall so antibiotics are generally ineffective Selective media needed |
|
What changes does M bovis cause in milk?
|
Characterized by sandy granules and tan colored milk
|
|
How is M bovis spread?
|
Spread through contaminated antibiotics, syringes milking units, common cloths, etc.
|
|
How do you know if a mastitis is caused by M bovis?
|
An increase in severe clinical mastitis cases that resist treatment, but with little other effect on the cow.
The involvement of more than one mammary quarter, sometimes all four. A marked drop in the milk production of affected cows. Abnormal udder secretions that may vary from watery milk with a few clots to a colostrum-like material. Chronically infected cows may show a tannish secretion with sandy or flaky sediments that resembles cooked cereal in a whey-like fluid. Udder secretions may become purulent and last for several weeks. |
|
How do you treat a M bovis infection?
|
You don’t!
Cull the cow and get her off the farm ASAP!! DO NOT feed Mycoplasma mastitis milk to calves!!! |
|
How can mycoplasma be prevented?
|
Pre & post milking teat dipping
Milk infected cows last Cull infected cows or segregate infected cows Culture replacements (home & purchase animals) Culture bulk tanks or know herd history |
|
What signs are seen that should make you suspect M bovis in the herd?
|
Mastitis following respiratory problems in herd
2. Young calf joint swelling and lameness 3. Young calf head tilt - inner ear infections 4. New knee and hock swelling on cows 5. multiple quarters with clinical mastitis |
|
What environmental organisms can cause mastitis?
|
Coliforms:
-e coli -klebsiella -enterobacter all Gram neg |
|
When does enivronmental mastitis occur?
|
Usually occurs periparturient
Late dry period Early lactation |
|
How does environmental mastitis occur?
|
Occurs because teat sphincter does not keep out fecal contaminants
|
|
Where in the environment can klebsiella be found?
|
Wood shavings- for bedding
|
|
What can happen to a cow with environmental mastitis?
|
Cow can spontaneously recover from infection
Cow can succumb to endotoxemia |
|
What are the clinical signs of coliform mastitis?
|
Acute to subclinical infections
Yellow to watery secretion Subnormal temperature Quarter can be hard and swollen Egg drop soup |
|
E coli are fecal organisms, how does e coli spread?
|
Poor hygiene (not cow to cow)
Higher incidence in hot summer (July-Aug) |
|
Does e coli produce acute or chronic mastitis?
|
Acute/toxic (15% will be severe & life threatening)
Rarely chronic (Klebsiella more common) |
|
What is the pathogenesis of e coli mastitis?
|
Coliform bacteria do not adhere to the mammary epithelial cells
If the cow has a strong immune system, the bacteria can be eliminated quickly -Coliform bacteria quickly multiply and die in the mammary gland -Bacteremia develops – hematogenous spread of bacteria to lungs and heart may lead to pneumonia and vegetative endocarditis These cows experience mild udder inflammation and temporary decrease in milk production When neutrophil influx into the udder is delayed or if the PMNs are not fully functional, the bacteria quickly multiply and the cow becomes systemically ill |
|
What are the clinical signs of endotoxemia?
|
Dehydration
Fever followed by subnormal temperature Tachycardia Tachypnea Injected sclera Rumen atony Worse cases, death |
|
Clin path will show what in a case of endotoxemia?
|
Severe neutropenia
Elevated fibrinogen Azotemia Hypocalcemia is common |
|
How is e coli mastitis treated?
|
IMM antibiotics vs frequent stripping
Systemic antibiotics Supportive care: Fluids NSAIDs Calcium Vitamin C?? Steroids?? |
|
How can e coli infections be prevented?
|
Clean & dry bedding
J-5 vaccination in dry period Feed cows at milking (time for teat sphincter to close) |
|
What are the clinical signs of a Klebseilla infection?
|
Similar to e coli:
Acute to subclinical infections Yellow to watery secretion Subnormal temperature Quarter can be hard and swollen |
|
Where in the environment if Klebsiella found?
|
Associated with soil contamination
Grows well in wood products Switch bedding Maintain high pH in bedding |
|
What are some other environmental organisms that can cause mastitis?
|
Pseudomonas
Protheca Yeasts |
|
where are Pseudomonas,Protheca and
Yeasts found? |
Pseudomonas:Contaminated water, pipes, heater, wash hoses, teat dip
Protheca:algae, wet soil mud Yeasts:excessive abx tx, Contaminated infusions |
|
How can environmental pathogens be controlled?
|
More difficult to control than the contagious pathogens
Most are resistant to germicides in teat dip and antibiotics in dry cow therapy Key is to ID source and remove (bedding, ponds, mud) |
|
What management steps can be taken to reduce exposure to environmental mastitis?
|
Clip or flame udders
Milk only clean dry teats Clean parlor, stalls, bedding Barrier dips Predip teats with germicide before milking – No water Keep cows standing after milking - feeding Sterile single-dose infusion products Sterile infusion techniques (alcohol swab |
|
What types of tx are available for mastitis cows?
|
IMM Therapy
..Injection of antibiotics into udder Systemic Therapy ..Antibiotics IV, IM, or SubQ Supportive Therapy ..Remove toxins – Frequent milkout ..Treat dehydration, swelling and pain ...Know bug Dry Cow Therapy Larger dose, longer acting product |
|
What are the 8 things to consider when developing a mastitis tx plan?
|
Consider the pathogen
Consider the cow’s history Consider the severity Consider the alternatives Institute treatment promptly Choose Appropriate Antibiotics Realize the limitations of antimicrobial sensitivity testing Consider the pharmaconkinetics and pharmacodynamics |
|
What steps can be taken to prevent contagious mastitis?
|
Proper Milking Techniques
Predipping Maintain milking equipment Milk contagious cows last |
|
What steps can be taken to prevent environmental mastitis?
|
Keep cows clean!
Proper Bedding Clean and dry General farm housekeeping Manure, water, flies Udder flaming, tail docking Cow comfort – Stalls Post dipping Barrier dips |
|
when plating milk samples for bacteriology, what plate type should be used?
|
Selective agar tri-plate (Blood agar, TKT agar, MacConkey agar):
|
|
Which organism causes mastitis in beef and dairy heifers?
|
Staph aureus (caused by flies on the end of teats)
|
|
What are the primary pathogens of mastitis in sheep and goats?
|
Staph aureus
Mycoplasma Rule out CAE/OPP |
|
Is mastitis common in camelids?
|
No
|
|
What are the predisposing conditions of udder edema?
|
Genetics
Nutritional management Obesity Lack of exercise |
|
What is udder edema?
|
Not usually painful and occurs when pitting edema develops symmetrically in the udder prior to parturition
Can become a chronic condition and persist throughout lactation |
|
How do you tx udder edema?
|
Treatment should be initiated if swelling threatens the udder support apparatus, or if the edema interferes with the ability to milk the cow
Massage, repeated as often as possible, and hot compresses stimulate circulation and promote edema reduction Diuretics Corticosteroids Reduce salt in diet |
|
What is the cause of bloody milk?
|
Small vessels rupture as a result of trauma or in conjunction with udder edema
Milk appears light pink or brown No treatment necessary Occasionally severe mastitis will cause bloody milk – guarded prognosis |
|
What is in colostrum?
|
Immunoglobulins
IgG1 is present in the highest concentration in colostrum and milk IgG1 concentrations decrease in maternal plasma 2-3 weeks before calving; from this time until parturition, maximum concentrations of IgG1 are present in lacteal secretions Ruminants are agammaglobulinemic at birth Colostrum can be absorbed across the intestinal epithelium during the first 24 hours of life |
|
What factors affect colostrum quality?
|
Older cows have higher IgG levels
High producing dairy cows can have lower quality colostrum Leaking milk before parturition The cow produces colostrum for 72 hours Colostral IgG concentrations are highest at the first milking after parturition and quickly decrease |
|
How do you tell good colostrum from bad?
|
Colostrometer
Measures the specific gravity Not an actual measurement – can only determine poor quality from acceptable quality Milk must be at room temperature for reading to be accurate |