Introduction:
Mastitis is a major and serious
problem in dairy industry throughout the world. This disease causes massive
economic fatalities to farmers in terms of production. Economical status of
dairy animal is based in its milk production. In case of cow front teats
produce more milk (60%) than rear teats (40%) and vice versa in case of
buffalo. If cattle lose its front left or front right teat then there will be a
huge economic loss.
According
to National Mastitis Council (NMC), USA:
“Mastitis
is an inflammation of mammary glands that happens in response to the injury for
purpose of neutralizing infectious agent to prepare way for healing and turned
to normal function.”
Normal
somatic cell count in milk is 200,000 and in case of mastitis it goes to
several thousands. Mastitic milk has 90 % neutrophils and 10% somatic cells. If
40 % neutrophils, there will be mild mastitis while in case of 90 %
neutrophils; there will be severe mastitis.
Effects of
Mastitis on Dairy Products:
Ø Mastitis affects
the quality of milk and there is increase in the number of bacteria. Common
sources of bacteria are inadequate cleaning of milking utensils, hands not
properly washed, skin of udder not properly cleaned and contamination of the
teat skin. There is a direct relationship between skin and mastitis. If dirty
skin then more chances of mastitis. By providing hygienic conditions mastitis
can be controlled and quality of milk and its byproducts can be improved.
Ø Increased
somatic cell count and increased neutrophils and macrophages also deteriorate
the quality of milk. Increased somatic cell count claims mastitis. So there is
direct relationship between mastitis and somatic cell count. But in late
lactation and newly parturating animals, there is also increase in somatic
cells.
Ø Whenever there
is rise in somatic cell count, casein content falls down (which is very
important protein). Similarly leakage of certain proteins from serum like
albumin, immunoglobulin and transferrin into milk also occurs.
Ø There is also an
increase in sodium and potassium ions.
Ø Calcium level
decreases.
Ø Normal pH of
milk is 6.6 but it may raise upto 6-9 or more in the milk collected from sub
clinically mastitic animal and even more in clinically mastitic animals.
Ø There is release
of proteolytic enzyme from blood like plasmin. Plasmin is excessive in blood
but low in milk. It cannot be destroyed at 140 oC. If it is high in milk then
deteriorate the quality of milk. Milk heated at 140 oC for 1.5 minute destroys
the Plasmin and some other enzyme like lipase. Lipase attack triglycerides to
convert them into free fatty acids, which produce offensive smell and rancid flavor
in milk.
Ø Watery milk
shows chronic type of inflammation. If watery secretion present in first few streaks
(about 10 streaks) then normal but if more than it then chronic mastitis.
Ø Plaques present
in milk show severe infection. If present at start of milking then shows
infection due to S. aureus. If at the end of milking then indicates animal
having TB. These plaques are normally present in milk in 1-2 days of lactation
and in last 2-3 days of lactation.
Modification in Milk
Associated with Somatic Cells Count:
|
Constituents
|
Normal Milk
|
Milk with high
Somtic cell Count
|
|
Solid non fat
|
8.9
|
8.8
|
|
Fat
|
3.5
|
3.2
|
|
Lactose
|
4.9
|
4.4
|
|
Total Protein
|
3.61
|
3.56
|
|
Total Casein
|
2.8
|
2.3
|
|
Whey protein
|
0.8
|
1.3
|
|
Serum albumin
|
0.02
|
0.07
|
|
Lactoferrin
|
0.02
|
0.10
|
|
Immunoglobulin
|
0.10
|
0.60
|
|
Sodium
|
0.057
|
0.105
|
|
Chloride
|
0.091
|
0.147
|
|
Potassium
|
0.173
|
0.157
|
|
Calcium
|
0.12
|
0.04
|
Types of
Mastitis:
Ø Latent Mastitis:
Pathological
organisms present in milk but no swelling of udder and normal cell count.
Ø Sub Clinical Mastitis:
Bacteria
and somatic cells present in milk and change in composition of milk but no
gross lesions.
Ø Clinical Mastitis:
It
is divided into three categories depending upon severity:
·
(a): Acute: There are
obvious symptoms of inflammation present on udder, change in color and
composition of milk and increased temperature.
·
(b): Sub acute: No obvious
change in udder but clots and plaques present in the milk.
·
(c): Chronic: Every acute
infection develops into chronic infection if not treated. In this phase major
changes are fibrosis of udder. There may be fibrotic mass particularly in teat
canal.
Ø Aseptic/Non Specific Mastitis:
It
is due to trauma or injury to the udder.
Etiology:
Ø Contagious Pathogens:
They
spread from quarter to quarter through contamination by hands, flies, wounds
etc. They always require host e.g. Staph aureus, Mycoplasma, Pasteurella. They
have very limited life in environment. In Pakistan mastitis caused by Staph
aureus and Streptococcus agalectia is 70-80 % of mastitis and rest of it is
caused by environment (E. coli)
Ø Environmental Opportunist:
The
primary source is the environment in which the animal lives. They spread by
direct contact of the teats to the bedding or mud, dirt and manure. Examples
are Coliform species like E.coli, Klebsella, Streptococcus uberis,
streptococcus agalactae, and streptococcus faecalis etc.
Ø Opportunist Pathogens:
This
group of mastitis pathogens includes around 30 different species of the genus
Staphylococcus (other than Staph aureus) and Corynebacterium bovis. They are
normally present on the teat skin and streak canal. Therefore they are in an
opportunistic position to colonize the teat canal and penetrate the udder.
Ø Endogenous Pathogens:
Etiological
agents of systemic diseases with mammary gland involvement like Leptospira,
Mycobacterium bovis etc.
Mode Of
Transmission:
Ø Hands of milker.
Staph aureus is present on skin, naries of human if no proper bath. He will
shift from one herd to other.
Ø Lack of proper
management i.e. proper teat dipping is not carried out, no antiseptic solution
is used and no sanitation measures are taken.
Ø Trauma during
sitting posture or due to kicking udder leads to mastitis.
Ø Folded thumb
milking particularly in villages damages the teat and causes adhesion and
increases the chances of mastitis.
Ø In old animals
teat canal is fragile and immune system is weak. So there are more chances of
infection in old animals.
Pathogenesis:
There
are three phases of mastitis:
Ø Invasive/Invasion Phase:
It
depends upon no. of bacteria. When bacteria enter, they multiply and increase
in population. So certain no. of bacteria is required for invasion. This
determines the infection rate. Any damage to teat canal provides opportunity to
bacteria to invade and multiply. Loose sphincter will also provide the
opportunity of entrance and adhesion to bacteria.
Ø Infection Phase:
Whenever
bacteria enter, the infection depends upon the nature of bacteria. If highly
pathogenic, then severe infection. Some bacteria are susceptible to antibiotics
and some are resistant. Staph aureus if capsulated it resists and more chances
of infection. If less immunoglobulin present in udder or teat canal then more
chances of infection.
Pre
existing leukocytes if more in number; less chances of infection. They cause
phagocytosis of bacteria. Stages of lactation also affect the severity of
infection e.g. in lactating phase milk flow does not allow bacteria to attach.
Similarly during lactation, treatment is difficult because antibiotics may flow
in milk. Dry period is the best time to treat mastitis because antibiotics will
stay for longer time in udder. The best time for infection is also the dry
period; bacteria once entered, remain there and cause infection.
Ø Inflammation Phase:
Inflammation
depends upon the pathogenecity of bacteria and the production of endotoxins,
particularly the endotoxins of S. aureus (α and ß) and E.coli that cause damage
to the capillaries of udder and cause the release of fluid in subcutaneous
parenchyma tissue. In case of E. coli there is huge number of endotoxins and
huge damage and inflammation. But S. aureus endotoxins cause less damage to the
vessels. They cause chronic mastitis and more fibrosis. Their ultimate target
is to damage milk alveoli.
Clinical
Findings:
Ø There is change
in udder size; size increases in acute cases while in chronic cases it
decreases due to fibrosis and atrophy
Ø Consistency of
udder is soft and hot in acute but hard in chronic due to fibrosis
Ø In case of
endogenous spread (like E.coli) systemic reaction may occur and cause
temperature, anorexia, depression and whenever increase in fever animal is off
feed
Ø In S. aureus
infection there is rise in temperature in early stages
Ø In case of
streptococcus no rise in temperature while in case of E.coli high temperature.
Diagnostic
Procedures:
Ø Direct Microscopic Method:
Put
0.1 ml of milk sample on slide, dry it and stain it with Newman Lampert’s Stain
and then count somatic cells with the help of microscope in certain area.
Multiply the cell counted with a working factor of microscope, it will give the
number of cells per ml of milk.
Ø The Coulter Counter:
It
allows the rapid and accurate determination of the number of particles above a
certain size in a suspension.
Ø Fossomatic Instrument:
It
is an automatic microscopic method for counting cells in liquids. Cells are
stained with ethidium bromide and are then excited with a high energy lamp,
causing them to emit light energy which is detected electronically; the results
being displayed are printed out for each successive sample. From the sample 0.2
ml is taken and transferred to a glass container on a rotary table where it is
mixed with preheated buffer and dye and stirred well. Part of the mixture is
then transferred to the periphery of a rotating disc, which serves as an object
plane for the microscope. The film is illuminated by a xenon arc lamp, the
light passes through lenses and a blue filter. Each cell produces an electrical
pulse, which is fed to an amplifier. The printout of the count needs to be
multiplied by 1000 to give number of cells per ml.
Ø NAGase Assay:
NAGase
(N-acetyl glucosamide) is a lysosomal enzyme. Its level increases due to
mastitis which can be detected for the diagnosis of mastitis. Kits to detect
are available.
Ø California Mastitis Test:
A
reagent is used in California Mastitis Test which is alkaline in nature.
Whenever mastitis occurs, there will be destruction of leukocytes due to
phagocytosis. As a result DNA content increases in milk which is acidic in
nature and causes the increase in the acidity of milk. Any alkaline reagent if
added, it will neutralize the milk. The reagent added in California mastitis
has alkyl aryl sulfoxide which will cause the precipitation or gel formation in
milk.
Ø Surf Field Mastitis Test:
A
test discovered by Prof. Dr. Ghulam Muhammad, Department of Clinical Medicine
and Surgery, Faculty of Veterinary Science, University of Agriculture,
Faisalabad. Make 3 % surf field solution: add 6 teaspoons of surf in half liter
water, mix it, filter the solution and heat it. Take milk and add equal volume
of 3% solution, swirl this mixture for half minute and then examine for precipitation
or gel formation (In case of mastitis). The test solution is stable for 6
months at room temperature. The solution should be shaken well before use.
Ø Strip Cup Method:
It
is the simplest method. Take few streaks in cups with black background and
observe any abnormality e.g. clots.
Ø Ground Test:
Take
few streaks on ground. If the absorbance of streak is quick in ground then
animal is –ve for mastitis but if the absorbance is slow then milk is mastitic.
Late absorbance is due to pus as mastitic milk is pus containing milk.
Ø Measuring Electrical Conductivity of Milk:
The
concentration of sodium and chloride increases in milk as a result of mastitis.
These ionic changes together with increase in milk pH and decrease of milk fat
lead to increased electrical conductivity of milk. Electrical conductivity
measuring can be converted into computer readable signal. Therefore, this
method is easily applicable to online automatic monitoring of udder health and
can be installed in milking machines. The method however, is not very specific
for mastitis.
Treatment:
We
have to target three things:
Ø Specific
treatment
Ø Symptomatic
treatment
Ø Supportive
treatment
First
of all determine the nature of mastitis and on the basis of nature of mastitis
and its etiological agent select antibiotics. Antibiotics can be administered through intramuscular or intra mammary
route. Whenever given through intramuscular route the best drugs to be given
are macrolides (erythromycin, tylosin), oxytetracyclin, cephlosporin,
chlorofluracin, and quinolines (norfloxacin). Tribrissen is also good. The best
approach is to give antibiotics through intra mammary route. Commercial Intra mammary
tubes are also available in market. For subsiding inflammation steroids may be
used in acute inflammation otherwise NSAIDS.
Vitamin AD3E may be used to
increase immunity. To enhance immunity, trace elements like zinc, copper, and
iodine may also be used. Biotechnological products like Interleuken-1,
Interleuken-2, and lysostaphin are also used.
Udder Toilet:
It
refers to infusing larger quantity of weak antiseptic solution into quarter and
withdrawing it. For this purpose acriflavin solution (1:10000 boiled in water)
is generally used. Remove milk from the udder and infuse the solution, remain
there for 5 minutes and then remove out with the help of syringe.
Permanent
Drying/Blocking of Affected Quarter:
If
quarter does not respond to antibiotic, infuse tincture iodine into that
quarter; it will cause irritation and block that quarter permanently. 50 ml of
chlorhexadene can also be used.
Basic Remedies:
Garlic,
lemon , ginger, red chilies, black pepper, black zera, dried ginger….dry for 5
days. Mix them in flour, sprinkle water and wrap in newspaper. Give for 5 days.
250
ml lemon and 500 gram sugar may also be given.
250
gram garlic and 1000 ml milk is cooked and given to animal for 2-3 days.
Control,
Prevention and Management:
Two
main objectives of control:
Ø Prevention of
new infection in the herd
Ø Reduction of
duration of existing infection
There
are five different plans to control mastitis which were devised by NMC
(National Mastitis Council), USA in 1990.
·
Pre
milking teat dipping
·
Post
milking teat dipping
·
Dry
cow therapy
·
Prompt
treatment of clinical cases
·
Culling
of chronic mastitic animals from the herd
Ø Pre Milking Teat Dipping:
Dip
the teats before milking with the. Dry the teats after pre dipping by towel or
tissue. Do not use same towel for more than one animal. Teat cups are available
having antiseptic in it like iodofores (0.1-1 % iodine). Dip the teats one by
one for 2-3 seconds. Quaternary ammonium compounds, chlorhexidine, and sodium
hypochlorite may also be used as dip solution.
Ø Post Milking Teat Dipping:
Organism
is present in environment and teat skin. In order to avoid it we go for post
milking dipping. After milking teat sphincter remains open for 30 minutes to 2
hours. It is ideal time for entry of organism to teat canal. So perform teat
dipping after milking. Solutions for post milking teat dipping are same as for
pre milking teat dipping.
Ø Dry Cow Therapy:
The
rate of new udder infections increases dramatically shortly after drying off
and remains elevated during the first 3 weeks of mammary involution. During the
first few days after drying off, the animal goes through a period of stress
that may predispose her to infections.
Up to 40% of all new intra mammary infections are established during the
first two weeks of the dry period and without dry cow therapy, 10 to 15% of the
quarters will become infected during the dry period. Dry cow treatment is aimed
at preventing new infection from occurring during this period of increased
susceptibility as well as curing existing infection and is beneficial against
both contagious and environmental pathogens. Advantages of dry cow treatment include the following:
·
The
cure rate is higher than during lactation
·
Higher
concentrations of drugs can be used
·
New
infections during the dry period are reduced except first 3 weeks after drying
off
·
Drug
residues in milk are avoided
Ø Prompt Treatment of Clinical Cases:
Despite
implementation of effective mastitis control measures, clinical cases still
occur. These cases should be treated promptly to maximize the chances of
recovery. Treatment of clinical cases involves intra mammary and parental
administration of antibiotics. Extreme care must be taken whenever anything is
being infused into udder. Careless treatment procedures can result in udder
infections resistant to treatment. Approach treatment in the same way a surgeon
approaches surgery.
·
Wash
hands with soap and water
·
Wash
teats and udder in sanitizing solution
·
Thoroughly
dry teats and udder with single service individual paper towels
·
Dip
teats in an effective germicidal teat dip
·
Allow
30 seconds of contact time before wiping off teat dip with an individual towel
·
Thoroughly
scrub the teat end with a cotton swab soaked in alcohol. If all four quarters
are being treated, start by cleaning the teat farthest from you and work toward
the closest teat.
·
Preferably
use commercial antibiotic products in single dose containers designed with
partial insertion arrangement formulated for dry cow therapy in single dose
containers. Do not allow the sterile canola to touch anything prior to
infusion.
·
After
infusion, remove canola, squeeze teat end with one hand, massage antibiotic up
into the quarter with the other hand. Dip teats in an effective germicidal teat
dip after treatment.
·
One
can also prepare infusion solutions and infused with the help of plastic part
of IV catheter (Branula # 18 or 20).
Ø Culling of Mastitic Animals:
·
Cull
mastitic animals from herd.
Management:
Ø Segregation of
healthy and infected animals and milking of healthy animals ahead of infected
animals
Ø Cull chronically
infected animals
Ø Purchase
mastitis-free animals (Surf Field Mastitis test -ive animals). Keep them segregated
for about 2 weeks. Retest with Surf test before adding to already existing
herd.
Ø Mastitis control
in heifers: The gradual building up of a separate heifer herd, clean at the
outset, is of great importance. The occasional appearance of mastitis in first-calving
heifers is said to be due to the habit of female calves sucking one another's
teats. This problem should be addressed through appropriate managemental
practices.
Ø Proper treatment
of teat and udder wounds
Ø Fly control
Ø General
cleanliness of farm
Ø Proper disposal
of mastitic milk of clinical cases
Ø Prepartum
milking of animals which develop mastitis close to calving: Many dairy animals
which have subclinical infections during the dry period often develop severe
swelling of the udder and teat a few weeks or days before calving. If such is
the case, one should start milking the diseased quarter (s) before parturition.
Appropriate treatment should also be given.
Proper nutrition: The
feed should be balanced in terms of energy, protein contents, as well as vitamins
and minerals.
No comments:
Post a Comment