59. Mastitis diagnosis and treatment in cattle Flashcards
Mastitis?
The mastitis
- Definition – mostly caused by microorganisms and rarely due to other cause
- Inflammatory response
- The infection
o Mostly through the teat canal (ascending)
o Mechanically through the skin of the udder through blood and lymphatic spreading (viruses)
• Economic impact of mastitis
o Direct cost
§ Discarded milk
§ Medicine and veterinary costs
o Indirect costs
§ Decreased milk price
§ Milk production decreases in the remaining lactation due to elevated SCC
§ Separation of the animal require labour
§ Cost of replacement heifers
§ Culling
Classification of mammary gland infections based on pathological changes?
Classification of mammary gland infections based on pathological changes
- Galactophoritis – gland cistern and teat cistern infection
- Parenchymal mastitis – minor cistern and ductus infection
- Interstitial mastitis – inflammation in the alveoli and the interstitial tissue between the lobules
Clinical forms of mastitis?
Clinical forms of mastitis
• Clinical mastitis: 20%
o Per acute
§ Abnormal milk
§ Abnormal mammary gland
§ Sick cow (elevation in clinical baseline values, shock exitus)
o Acute
§ Abnormal milk
§ Abnormal mammary gland
o Manifest by inflammation changes in the tissue such as redness, heat, pain and swelling
o Subacute
§ Abnormal milk only
§ Manifest by clots, flakes, and or changes in the colour and consistency of the milk secretion
o Chronic
§ Chronic form with fibrosis, nodules and/or abscessation in the mammary gland
• Subclinical mastitis: 80%
o Presence of inflammation with normal appearing mammary gland and visibly normal milk
Diagnosis of clinical and subclinical mastitis?
Diagnosis of clinical and subclinical mastitis
• Clinical mastitis
o Alterations in the milk + clinical signs of the animal
§ After milking the 1st strips, we preform test milking
§ During this we observe the mammary gland
§ In case of positivity separated milking + treatment
• Subclinical mastitis
o Somatic cell count (SCC)
§ Leukocytes mean 80% of the somatic cells in uninfected quarters and 99% in uninfected
quarters
o Milk lactose concentration decrease
§ In damaged tissue, the secretory cells are unable to lactose biosynthesis
o Milk lactate dehydrogenase (LDH) concentration increase
§ Due to cell damage LDH is released into the milk (secretory cells + leucocytes)
o Milk N-acetyl-b-D-glucosamidase (NAGase) -increase
§ Due to epithelial cell damage exerts from cell lysosomes
o Acute phase proteins (haptoglobin, milk amyloid A)
§ Due to increased permeability, they cross the blood-milk barrier and occur in milk
o Electrical conductivity (EC) of the milk increase
§ Sodium chloride increase, potassium decreases
Subclinical mastitis direct and indirect?
Subclinical mastitis: somatic cell count determination
• Direct
o Microscopic determination
o Automated electronic cell counters (flow cytometry)
o Portable counters (DeLaval, Porta SCC)
• Indirect
o California milk test (CMT)
Evaluation of CMT?
Additional tools in diagnostic of intramammary infections?
Additional tools in diagnostic of intramammary infections
- Bacteriological culture sampling
- PCR sampling
- The sampling
o At the level of the quarter
o At the level of the cow
o At the of the herd
• Selection criteria
o Clinically affected animals before the
therapy
o At the time of drying off
o After calving
o Animals with high SCC
• Bacteriological culture sampling
o Easy culturing (! mycoplasma spp!)
• Bulk tank microbiology
o Raw milk quality testing
o IMI link: S.aureas, strep agalactiae and mycoplasma spp.
o Other pathogens: not only from the cow
o Standard plate count – SPC (bactoscan, flow cytometry)
o Target numbers of bulk tank microbiology
- On farm culturing method
- Classical laboratory culturing
Sampling for microbiological culture sampling?
Sampling guide for microbiological culture sampling
0. Clan hand or glove
1. Cleaning and drying of the teat
2. Predisposing and towel cleaning
3. Milking 1st 4-6 strings
4. Cleaning the teat end with alcohol on a towel
5. Keeping the tube in 45 degrees on string is milked into the tube
6. Identification of the tube
7. Freezer (coliform!!)
8. Cooling bag, lab, transport
• Staph Aureus- at the end of milking
PCR?
PCR – polymerase chain reaction
- Advantage within 4 hours
- Multiplex PCR and real time PCR assays
- Not able to distinguish between dead and alive organisms
Pharmacological therapy of mastitis?
Pharmacological therapy of mastitis
• Cases occurring in early lactation
o The immunity of the cow is impaired
o There are fewer circulating neutrophils, harder to get
into the udder
o Bacteria easier causing a septicaemia
• Answer if the immune system
o Release of immature neutrophils from BM
o Less effective phagocytosis
o EC release of ROS (reactive oxygen species)
o Much more tissue damage
o Endotoxins are free in tissue to cause more inflammation
o Maybe toxic shock
• Normal cow
o Phagocytosis
o Internal killing by ROS
o Endotoxins protected
• Periparturient cow
o No successful phagocytosis
o External killing by ROS
o Endotoxins are free in tissue
• Because all of these in the periparturient period toxic mastitis is more common Mastitis Acuta Gravis
Antibiotic treatment?
Antibiotic treatment
- 1st steps when choosing AB
- Lactating cow vs. Dry cow
- How many administrations?
- Further medical therapy
- Initiation of treatment as early as EC change
- Faster and more complete recurrence than self-cure
- Decrease the chance of remission
- Crease milk yield drop
How to choose AB?
How to choose AB?
- Sensitivity
- Bactericidal or bacteriostatic
- Withdrawal period
- Price
• Intramammary treatment
o The conus is partially inserted into the teat canal
o Close the end of the teat and massage up to the direction of the udder
o Post dip all 4 teats
o Record treatment
• AB treatment
o Local treatment (IMM)
o Parenteral treatment (IM)
o Combination (IMM+IM)
o Aggressive treatment
§ Longer duration
§ Higher dose
- For parenteral treatment only those AB, which reach sufficient concentration in the alveoli
- If no cure at 2 days, do we need to change treatment?
- If at day 4 still no progression towards cure
o Change AB
o Preferably on the basis of bacteriology and sensitivity
o Never treat longer than 7 days
o High likelihood of a yeast – check for it
o Cull or dry off quarte
Effectiveness of treatment?
Effectiveness of treatment
- Bacteriological elimination à <400,000 SCC ↓
- Up to 4-6 weeks
- No cure: subclinical mastitis (SCC remains high)
- Clinical cure rate
- It is normal for cured cows to still have clots at day 4 or 5
General guidelines of AB usage?
General guidelines
• AB usage should involve veterinary guidance and extra label use should be avoided when on label use is a
possibility
• AB should only be used when there is a reasonable likelihood that a bacterial infection that is sensitive to the
proposed AB is present
- Narrow spectrum AB that are less critical for treating human illness should be used as 1st choice
- Antibiotics should be sued for as short a
duration as possible
- No treatment, culling
- Low cure rate
- Beta lactamase positivity ↓↓↓
- In vitro susceptibility ≠ cure
Aditional treatments and vaccination?
Additional treatments
- More milking events, oxytocin
- Fluid therapy
- Anti-inflammatory drugs (meloxicam, metamizole)
- Glucose IV
- Non-AB treatment
o Relative low number of scientific evidence
o Disinfectants
o Bacterial culture
Vaccination
- Staph aureus
- E.coli
- Contra versional results
