Lesson 24 - Mammary Conditions

How can we determine if a cow has subclinical mastitis?

increased WBC in mammary glands

What cells could be found in the mammary gland?

1. somatic cells

2. neutrophils

What does it mean if you have one clinical cow with mastitis?

you probably have 10 subclinical

What would mild mastitis look like?

abnormal milk

What would moderate mastitis look like?

1. abnormal milk

2. swollen firm gland

What would severe mastitis look like?

1. abnormal milk

2. swollen firm gland

3. sick animal

What systemic clinical signs are seen with severe mastitis?

1. fever

2. tachycardia

3. weakness

4. shock

What are the agents that cause contagious mastitis?

1. streptococcus agalactiae

2. staphylococcus aureus

3. mycoplasma bovis

What are the environmental gram positive agents that can cause mastitis?

streptococcus spp

What are the environmental gram-negative agents that can cause mastitis?

Escherichia coli

How do we diagnose contagious metritis?

culture and sensitivity

How do we diagnose environmental gram positive metritis?

culture and sensitivity

What is the most common type of mastitis?

contagious

What are characteristics of contagious metritis?

1. organisms live on teats

2. animal to animal spread

3. agents do not survive in the environment

What type of mastitis is mostly subclinical?

contagious

What type of mastitis is mostly clinical?

environmental

When you suspect a contagious metritis case, what should you look at first for control and prevention?

milk hygiene

What are characteristics of environmental mastitis?

1. agents found in the environment

2. doesn't spread easily from animal to animal

3. difficult to prevent

4. infections last days to weeks

What type of clinical presentation is common with contagious Staph. aureus metritis?

1. subclinical

2. mild to severe mastitis

3. gangrenous mastitis

4. recurrent mild clinical flare ups

What are the chronic clinical signs of Staph. aureus?

1. high SCC

2. induration of the udder

3. drop milk production

4. atrophy

What are the acute clinical signs of Staph. aureus?

1. swelling of gland with fever

2. milk is abnormal with thick clots and pus

What is a production concern with Staph. aureus mastitis?

major loss of milk production

What type of laboratory testing characteristic does Staph. aureus have?

coagulase positive

What is the primary source of Staph. aureus?

infected cows but widespread in the dairy environment

What type of treatment for Staph. aureus mastitis?

intramammary treatment with beta-lactams if not resistant

Why is Staph. aureus mastitis difficult to treat?

present in the tissue not the milk

Why is Staph. aureus mastitis difficult to diagnose?

it is intermittently shed so one culture and sensitivity may not catch it

What gives the best results for treating Staph. aureus?

1. cull chronic infected or resistant to treatment

2. dry cow therapy with long term antibiotics in each quarter

How do we prevent Staph. aureus mastitis?

1. milking hygiene

2. milk the positives last

3. treat all quarters at dry off with dry cow antibiotics

4. cull chronically infected or resistant to treatment

What clinical presentations are seen with Strep. agalactiae?

1. subclinical

2. periodic acute mastitis

What is the transmission like with Strep. agalactiae?

highly contagious with the cow as the reservoir

What are the production impacts of Strep. agalactiae?

severe drop in milk so a costly disease

If a bulk tank has a sudden increase in SCC, what agent do you suspect?

Streptococcus agalactiae

What are the clinical signs of Strep. agalactiae mastitis?

1. gland is swollen and warm

2. milk is watery and contains clots

3. gradual fibrosis of udder if not treated

How do we treat Strep. agalactiae?

intramammary treatment with beta-lactams; segregate and milk last

Which contagious metritis agent is easier to treat?

Streptococcus agalactiae

How do we prevent Strep. agalactiae?

1. treat all quarters in positive cows

2. keep screening herd

3. good milking hygiene

4. pre and post dip teats

5. culture cows before purchase

6. treat all cows at dry off

What is a less common form of contagious mastitis?

Mycoplasma bovis

What pathogen starts in one quarter and spreads to all of them in most cases?

Mycoplasma bovis

How is Mycoplasma bovis spread?

from cows to calves

What are the clinical signs of M. bovis mastitis in cows?

1. mastitis

2. polyarthritis

What are the clinical signs of M. bovis in calves?

1. bronchopneumonia

2. otitis

3. polyarthritis

What joint commonly shows symptoms from M. bovis polyarthritis?

carpus

What clinical sign would be seen with M. bovis causing otitis?

head tilt

What is a common risk factor for M. bovis mastitis?

stress

How is M. bovis mastitis often found?

typically cows that have mastitis that doesn't respond to treatments

What is a good management rule to help prevent M. bovis transmission to calves?

do not feed unpasteurized, discarded milk to calves

What is seen with subclinical M. bovis mastitis?

1. decent milk production with low-moderate SCC

2. intermittent shedding

What are clinical signs of M. bovis mastitis?

1. multiple quarters

2. acute inflammation

3. herd diseases

4. watery to purulent milk

5. fine, sandy material, flakes or floccules settles out leaving a turbid whey-like supernatant

6. sharp drop in production

What is the treatment for M. bovis mastitis?

requires macrolides but no intramammary ones exist and systemic macrolides are not allowed in lactating dairy cattle; so no treatment/cull

How do we prevent and control M. bovis mastitis?

1. cull positives

2. culture clinical and fresh cows

3. monitor bulk tank every 2 weeks or monthly until resolved

Why do we cull for M. bovis?

1. no treatment

2. lifelong carriers

What clinical presentations are seen with environmental gram positive pathogens?

1. ~50% are clinical

2. mild to moderate

3. clinical for 5-7 days

How do we treat environmental gram positive pathogens?

1. spontaneously resolved after several weeks

2. responds well to intramammary treatment

3. cephalothin and penicillin good options

What are the environmental gram negative pathogens?

1. Escherichia coli

2. Klebsiella sp.

3. Enterobacter sp.

4. Serratia sp.

What season is E. coli mastitis seen?

1. hot summer

2. mid-winter when housing is poor

What environment does Klebsiella like?

shavings, sawdust, compost

When is environmental gram negative mastitis most common?

during dry period

What is the clinical presentation like for environmental gram negative pathogens?

subclinical to clinical after calving

What can happen in some cases of environmental gram negative mastitis?

eliminate disease without treatment if they have a strong immune system

What happens if there isn't a strong enough immune system to fight off environmental gram negative mastitis?

1. rapid multiplication and then die in mammary gland

2. LPS released from cell wall causes inflammatory cascade

3. bacteremia, septicemia

4. pneumonia, vegetative endocarditis

5. clinically and systemically sick = toxic mastitis

What are clinical signs of coliform mastitis?

1. acute swelling of the gland

2. serous fluid

3. systemically ill

How do we diagnose coliform mastitis?

1. culture and sensitivity

2. blood work

What blood work changes are seen with coliform mastitis?

1. severe neutropenia

2. elevated fibrinogen

3. azotemia

4. hypokalemia

5. hypo or hyperglycemia

What is the good news with coliform mastitis?

doesn't permanently damage the gland like contagious agents if the animal lives

How do we treat coliform mastitis?

1. hypertonic saline followed by oral fluids

2. IV fluids if farmer can afford it

3. systemic or intramammary antibiotics

4. NSAIDs

5. frequent stripping every 2-4 hours

How do we prevent coliform mastitis?

1. clean stalls

2. bedding

3. feed after milking to keep standing until teat sphincter closes

4. vaccination

What is the vaccination schedule for coliform mastitis?

first dose during dry off, second dose in 2-4 weeks, third dose 2-4 weeks later

What is milk residue testing mostly testing for?

beta lactams

What are most residue violations due to?

1. failure to ID treated cows

2. failure to observe withhold times

3. keep records

What are the consequences of residue violations?

1. dump milk for 2-3 days

2. fines

3. loss of permits

What do we know about mastitis in beef cattle?

1. staph aureus most common

2. gangrenous staph aureus in heifers more than older cows

3. transmitted by flies

What is the most common pathogen in small ruminant mastitis?

Staphylococcus aureus

If you are investigating small ruminant mastitis and you can't culture anything, what should you suspect?

Mycoplasma mycoides

What must you rule out with mastitis in small ruminants?

OPP/CAEV

What does mastitis from OPP/CAEV look like?

1. firm udder but reduced or no milk

2. milk is normal

3. severe fibrosis and agalactia aka hard bag

What cows typically get udder edema?

first calf heifers

What causes udder edema?

increased capillary hydrostatic pressure from sudden increase in mammary blood flow

What is the concern with udder edema?

1. stress on the suspensory ligament

2. milking machine attachment issues

What is the clinical presentation for udder edema?

1. pitting edema, can progress to forelimbs

2. symmetrical and cool to touch

3. systemically normal just uncomfortable

4. normal milk on CMT

How do we treat udder edema?

diuretics (furosemide) if needed and time; may need to supplement potassium

How do we prevent udder edema?

1. reduce NaCl intake late gestation

2. try diet manipulation; grass hay and corn silage to dry cows

When is it normal to see bloody milk?

after calving in some cows and heifers

What does normal bloody milk look like?

colostrum and early milk can be light pink to brown

What causes bloody milk?

capillary rupture from trauma or udder edema

What is the treatment for bloody milk post-calving?

no treatment needed and it is safe for calves

What should you do for bloody milk when it is seen not immediately post-calving?

look for severe mastitis or larger vessel erosion from bacteremia

Where are udder abscesses typically located?

not within the gland, typically subcutaneous

How do you treat an udder abscess?

treat like a normal abscess; possibly drain

What is something you can use to help you drain an udder abscess without hitting important parenchyma?

ultrasound

What could be a sequelae to an udder abscess?

fibrosis of tissue which could lead to decrease production

Where do you see udder sores in heifers?

between leg and udders

Where do you see udder sores in cows?

between the front two quarters

What can udder sores in cows lead to?

udder cleft dermatitis

What is the risk of udder sores in cows?

erosion into a large vessel resulting in hemorrhage

How do we treat udder sores?

1. drying agent

2. topical medications

3. fly control

What is the goal with udder sores?

try to prevent or treat early

What can cause lesions on the teat end?

1. trauma

2. frost bite

3. chemical injury

4. masses

5. milking machine

What do you do with teats that have frost bite?

1. stop dipping

2. if in multiple quarters then cull

What can cause chemical injury to teat ends?

teat dip irritation