• TABLE OF CONTENTS
HIDE
 Front Cover
 Front Matter
 Table of Contents
 Definition and economic import...
 Causes of mastitis
 Path of entry of the causative...
 Means of transmitting the causative...
 Some factors that predispose cattle...
 Course of the disease
 Symptoms and lesions of mastit...
 Diagnosis of infected udders
 Control of mastitis through...
 Penicillin aids in mastitis...
 Summary and conclusions














Group Title: Bulletin - University of Florida. Agricultural Experiment Station ; no. 424
Title: Infectious bovine mastitis
CITATION THUMBNAILS PAGE IMAGE ZOOMABLE
Full Citation
STANDARD VIEW MARC VIEW
Permanent Link: http://ufdc.ufl.edu/UF00015136/00001
 Material Information
Title: Infectious bovine mastitis
Series Title: Bulletin University of Florida. Agricultural Experiment Station
Physical Description: 16 p. : ill. ; 23 cm.
Language: English
Creator: Sanders, D. A ( Dorsey Addren )
Publisher: University of Florida Agricultural Experiment Station
Place of Publication: Gainesville Fla
Publication Date: 1946
 Subjects
Subject: Mastitis   ( lcsh )
Cows -- Diseases   ( lcsh )
Genre: government publication (state, provincial, terriorial, dependent)   ( marcgt )
non-fiction   ( marcgt )
 Notes
Statement of Responsibility: by D.A. Sanders.
General Note: Cover title.
Funding: Bulletin (University of Florida. Agricultural Experiment Station)
 Record Information
Bibliographic ID: UF00015136
Volume ID: VID00001
Source Institution: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: aleph - 000925494
oclc - 18251356
notis - AEN6145

Table of Contents
    Front Cover
        Page 1
    Front Matter
        Page 2
        Page 3
    Table of Contents
        Page 4
    Definition and economic importance
        Page 5
    Causes of mastitis
        Page 6
    Path of entry of the causative microorganisms
        Page 6
        Page 7
    Means of transmitting the causative microorganisms
        Page 7
    Some factors that predispose cattle to mastitis
        Page 8
    Course of the disease
        Page 8
        Page 9
    Symptoms and lesions of mastitis
        Page 9
    Diagnosis of infected udders
        Page 10
    Control of mastitis through sanitation
        Page 11
        Page 12
        Page 13
        Page 14
    Penicillin aids in mastitis control
        Page 15
    Summary and conclusions
        Page 16
Full Text



September, 1946


UNIVERSITY OF FLORIDA
AGRICULTURAL EXPERIMENT STATION
HAROLD MOWRY, Director
GAINESVILLE, FLORIDA










INFECTIOUS BOVINE MASTITIS

By D. A. SANDERS


Fig. 1.-Bovine mastitis is a herd problem that can be controlled by good
management methods and milking practices.


Bulletin 424









BOARD OF CONTROL


J. Thos. Gurney, Chairman, Orlando
N. B. Jordan, Quincy
Thos. W. Bryant, Lakeland
M. L. Mershon, Miami
J. Henson Markham, Jacksonville
J. T. Diamond, Secretary, Tallahassee




EXECUTIVE STAFF

John J. Tigert, M.A., LL.D., President of the
University3
H. Harold Hume, D.Sc., Provost for Agricul-
ture
Harold Mowry, M.S.A., Director
L.:O. Gratz, Ph.D., Asst. Dir., Research
W. M. Fifield, M.S., Asst. Dir., Admin.
J. Francis Cooper, M.S.A., Editor3
Clyde Beale, A.B.J., Associate Editor3
Jefferson Thomas, Assistant Editors
Ida Keeling Cresap, Librarian
Ruby Newhall, Administrative Managers
K. H. Graham, LL.D., Business Managers
Claranelle Alderman, Accouhtant3



MAIN STATION, GAINESVILLE


AGRONOMY

W. E. Stokes, M.S., Agronomist'
Fred H. Hull, Ph.D., Agronomist
G. E. Ritchey, M.S., Agronomist2
G. B. Killinger, Ph.D., Agronomist
W. A. Carver, Ph.D., Associate
Roy E. Blaser, M.S., Associate5
H. C. Harris, Ph.D., Associate
Fred A. Clark, B.S., Assistant



ANIMAL INDUSTRY

A. L. Shealy, D.V.M., An. Industrialist' 3
R. B. Becker, Ph.D., Dairy Husbandmana
E. L. Fouts, Ph.D., Dairy Technologist3
D. A. Sanders, D.V.M., Veterinarian
M. W. Emmel, D.V.M., Veterinarian3
L. E. Swanson, D.V.M., Parasitologist
N. R. Mehrhof, M.Agr., Poultry Husb.S
G. K. Davis, Ph.D., Animal Nutritionist
R. S. Glasscock, Ph.D., An. Husbandman
P. T. Di: Arnold, M.S.A., Asst. Dairy Husb.3
C. L. Comar, Ph.D., Asso. Biochemist
L. E. Mull, M.S., Asst. in Dairy Tech.
Katherine Boney, B.S., Asst. Chem.
Ruth Taylor, A.B., Asst. Biochemist
J. C. Driggers, B.S.A., Asst. Poultry Husb.
Glenn Van Ness, D.V.M., Asso. Poultry
Pathologist
John S. Folks, B.S.A., Asst. An. Hush.


ECONOMICS, AGRICULTURAL

C. V. Noble, Ph.D., Agri. Economist'1
Zach Savage, M.S.A., Associate3
A. H. Spurlock, M.S.A., Associate
Max E. Brunk, M.S., Associate6
D. E. Alleger, M.S., Associate

Orlando, Florida (Cooperative USDA)
G. Norman Rose, B.S., Asso. Agr. Economist
J. C. Townsend, Jr., B.S.A., Agr. Statistician2
J. B. Owens, B.S.A., Agr. Statisticians


ECONOMICS, HOME

Ouida D. Abbott, Ph.D., Home Econ.2
R. B. French, Ph.D., Biochemist

ENTOMOLOGY

A. N. Tissot, Ph.D., Entomologist and Act-
ing Head of Dept.
H. E. Bratley, M.S.A., Assistant

HORTICULTURE

G. H. Blackmon, M.S.A., Horticulturist'
A. L. Stahl, Ph.D., Asso. Horticulturist
F. S. Jamison, Ph.D., Truck Hort.
Byron E. Janes, Ph.D., Asso. .Hort.
R. A. Dennison, Ph.D., Asso. Hort.
R. K. Showalter, M.S., Asso. Hort.
_R..J. Wilmot, M.S.A., Asst. Hort.
R. D. Dickey, M.S.A., Asst. Hort.
Victor F. Nettles, M.S.A., Asst. Hort.
J. Carlton Cain, B.S.A., Asst. Hort.5
F. S. Lagasse, Ph.D., Asso. Hort.2


PLANT PATHOLOGY

W. B. Tisdale, Ph.D., Plant Pathologisti
Phares Decker, Ph.D., Asso. Plant Path.
Erdman West, M.S., Mycologist and Botanist
Lillian E. Arnold, M.S., Asst. Botanist

SOILS

F. B. Smith, Ph.D., Chemist'1
Gaylord M. Volk, M.S., Chemist
J. R. Henderson, M.S.A., Soil Technologist
J. R. Neller, Ph.D., Soils Chemist
Nathan Gammon, Jr., Ph.D., Soils Chemist
C. E. Bell, Ph.D., Associate Chemist
L. H. Rogers, Ph.D., Associate Biochemist
R. A. Carrigan, B.S., Asso. Biochemist
H. W. Winsor, B.S.A., Assistant Chemist
Geo. D. Thornton, M.S., Asst. Microbiologist2
J. B. Cromartie, B.S.A., Soil Surveyor
R. E, Caldwell, M.S.A., Asst. Soil Surveyor4
Wade McCall, B.S., Asst. Chemist


1 Head of Department.
2 In cooperation with U. S.
3 Cooperative, other divisions, U. of F.
In Military Service.
6 On leave.










BRANCH STATIONS

NORTH FLORIDA STATION, QUINCY

J. D. Warner, M.S., Vice-Director in Charge
R. R. Kincaid, Ph.D., Plant Pathologist
W. H. Chapman, M.S., Asso. Agron.
R. C. Bond, M.S.A., Asso. Agronomist
L. G. Thompson, Ph.D., Soils Chemist
Frank D. Baker, Jr., B.S., Asst. An. Husb.

Mobile Unit, Monticello
R. W. Wallace, B.S., Associate Agronomist

Mobile Unit, Milton
Ralph L. Smith, M.S., Associate Agronomist

Mobile Unit, Marianna
R. W. Lipscomb, M.S., Associate Agronomist


Mobile Unit, Wewahitchka
J. B. White, B.S.A., Associate Agronomist


CITRUS STATION, LAKE ALFRED

A. F. Camp, Ph.D., Vice-Director in Charge
V. C. Jamison, Ph.D., Soils Chemist
J. B. Redd, Ph.D., Insecticide Chemist
W. L. Thompson, B.S., Entomologist
J. T. Griffiths, Ph.D., Entomologist
R. F. Suit, Ph.D., Plant Pathologist
E. P. Ducharme, M.S., Plant Pathologist
J. E. Benedict, B.S., Horticulturist
B. R. Fudge, Ph.D., Associate Chemist
C. R. Stearns, Jr., B.S.A., Asso. Chemist
James K. Colehour, M.S., Research Chemist
T. W. Young, Ph.D., Asso. Horticulturist
J. W. Sites, M.S.A., Asso. Horticulturist
H. O. Sterling, B.S., Asst. Horticulturist
J. A. Granger, B.S.A., Asst. Horticulturist
H. J. Reitz, M.S., Asso. Plant Path.
Francine Fisher, M.S., Asso. P1. Path.

EVERGLADES STA., BELLE GLADE

R. V. Allison, Ph.D., Vice-Director in Charge
J. W. Wilson, Sc.D., Entomologist*
F. D. Stevens, B.S., Sugarcane Agron.
Thomas Bregger, Ph.D., Sugarcane
Physiologist
G. R. Townsend, Ph.D., Plant Pathologist
B. S. Clayton, B.S.C.E., Drainage Eng.2
W. D. Wylie, Ph.D., Entomologist
W. T. Forsee, Jr., Ph.D., Asso. Chemist
Robt. L. Cassell, Ph.D., Asso. Plant Path.
R. W. Kidder, M.S., Asst. An. Husb.
T. C. Erwin, Assistant Chemist
R. A. Bair, Ph.D., Asst. Agronomist
Earl L. Felix, Ph.D., Asst. Plant Path.
C. C. Seale, Asst. Agronomist
L. O. Payne, B.S.A., Asst. Agronomist
R. C. Ladeburg, B.S.A., Asst. Hort.
Russel Desrosiers, M.S., Asst. Plant Path.
N. C. Hayslip, B.S.A., Asst. Hort.


SSUB-TROPICAL STA., HOMESTEAD

Geo. D. Ruehle, Ph.D., Vice-Director in
Charge
H. I. Borders, M.S., Asso. Plant Path.
D. O. Wolfenbarger, Ph.D., Asso. Ento-
mologist
R. W. Harkness, Ph.D., Asst. Chemist


W. CENT. FLA. STA., BROOKSVILLE

Clement D. Gordon, Ph.D., Asso. Poultry
Geneticist in Charge2


RANGE CATTLE STATION, ONA

W. G. Kirk, Ph.D., Vice-Director in Charge
E. M. Hodges, Ph.D., Associate Agronomist
D. W. Jones, B.S.A., Asst. Ap. Husb.
E. R. Felton, B.S.A., Asst. An. Husb.


CENTRAL FLORIDA STATION, SANFORD
R. W. Ruprecht, Ph.D., Chemist in Charge
A. Alfred Foster, Ph.D., Asso. Hort.
J. C. Russell, M.S., Asst. Entomologist
Ben F. Whitner, Jr., B.S., Asst. Hort.



FIELD STATIONS

Leesburg
G. K. Parris, Ph.D., Plant Path. in Charge

Plant City
A. N. Brooks, Ph.D., Plant Pathologist

Hastings
A. H. Eddins, Ph.D., Plant Pathologist
E. N. McCubbin, Ph.D., Truck Horticulturist

Monticello
S. O. Hill, B.S., Asst. Entomologist2 4
A. M. Phillips, B.S., Asst. Entomologist2

Bradenton
J. R. Beckenbach, Ph.D., Horticulturist in
Charge
E. G. Kelsheimer, Ph.D., Entomologist
A. L. Harrison, Ph.D., Plant Pathologist
David G. Kelbert, Asso. Horticulturist
E. L. Spencer, Ph.D., Soils Chemist
Robert O. Magie, Ph.D., Hort., Glad. Inv.
Donald S. Burgis, M.S.A., Asst. Hort.

Lakeland
Warren 0. Johnson, Meteorologist2

1 Head of Department.
2 In cooperation with U. S.
a Cooperative, other divisions, U. of F.
In Military Service.
I On leave. '



























CONTENTS


Page


DEFINITION AND ECONOMIC IMPORTANCE-..--...........-- ..-..........

CAUSES OF MASTITIS ........----.-------...........--------- ----------

PATH OF ENTRY OF THE CAUSATIVE MICROORGANISMS .......................--

MEANS OF TRANSMITTING THE CAUSATIVE MICROORGANISMS .................


SOME FACTORS THAT PREDISPOSE CATTLE TO MASTITIS ......................


COURSE OF THE DISEASE ............... ...........- ..

SYMPTOMS AND LESIONS OF MASTITIS ..................

DIAGNOSIS OF INFECTED UDDERS ...................

CONTROL OF MASTITIS THROUGH SANITATION ......

Preparing the Udder for Milking .............-


Precautions with Milking Machines ..............


Additional Precautions ... ............ ..........


PENICILLIN AIDS IN MASTITIS CONTROL .............


SUMMARY AND CONCLUSIONS ........................


....-- --...... .. ...... ............. .... 8


................................... .. 9


-..... ...-........ .......... ... .. 10

................ .... ..... ........ 1


---... ................ 12


........ .. ........ .......... 12


--........-..-.... ............... 13


................. ......... ..... 15

----.... .. ...... 16









INFECTIOUS BOVINE MASTITIS

By D. A. SANDERS

DEFINITIONS AND ECONOMIC IMPORTANCE

Infectious bovine mastitis, infectious mammitis or garget is
a bacterial disease affecting the milk secreting glands or udders
of cattle. The disease is widespread, being especially preva-
lent in the highly developed dairy sections throughout the world.
From an economic standpoint mastitis is widely recognized as
the most important disease affecting dairy cattle. Certain types
of mastitis also have important public health aspects.
Losses resulting from the destructive action produced by bac-
terial infections upon the mammary glands are reflected in num-
erous ways. Invasion of the mammary glands by pathogenic
bacteria often is responsible for inflammation of these organs
which results in permanent injury and loss of function of the
glandular or milk secreting tissues. Milk from diseased udders
frequently has a high bacterial content and is of poor quality.
In many instances the udder secretion may be altered to such
an extent that it does not resemble milk. Strictures, indura-
tions, abscesses, gangrenous areas of the udder tissues, blind
and asymmetric quarters frequently result from these infections.
In some instances death of affected animals occurs from sep-
ticemia. Once an animal's udder becomes infected, it often
remains a carrier or spreader of the causative microorganisms
even though no gross clinical evidence of the disease is present.
Such unrecognized infected cattle may serve to disseminate mas-
titis throughout an entire herd unless strict precautionary mea-
sures against its spread are constantly maintained.
The necessity for a clearer understanding of the problems
connected with prevention and control of infectious bovine
mastitis as occurring among dairy herds resulted in an inves-
tigation of the disease by this station. The purpose of this
bulletin is to present practical facts concerning mastitis and
to outline measures that have proved to be fundamentally es-
sential in controlling and preventing spread of the disease under
conditions existing in the herds observed. Due to many dif-
ferences in environment and management practices, no claim
can be made that solution of mastitis problems peculiar to in-
dividual herds is herewith presented.







Florida Agricultural Experiment Station


CAUSES OF MASTITIS

Numerous types of microorganisms, including species of
streptococci, staphylococci, diplococci, coliform and other bac-
teria, either alone or in combination, have been described as the
causative agents of mastitis. While bovine mastitis may result
from infections of the udder with several species of micro-
organisms, the most common infectious types encountered in
the herds under observation are associated with the presence of
streptococci and staphylococci within the udder. In studying
the bacterial flora of the udder during outbreaks of mastitis
occurring over a wide area, Streptococcus agalactiae frequently
was found to be associated with the disease. This streptococcus
primarily is an inhabitant of the mammary glands of cattle.
Environmental conditions within the udder tissues are ideal
for its parasitic existence and propagation. That this micro-
organism is able to maintain and propagate itself within the
udder tissues is demonstrated by its continued presence in the
milk during succeeding lactations. Under natural conditions
S. agalactiae is thought not to exist for great lengths of time
outside the udder tissues.
Species of staphylococci, which are common pus and toxin-
producing microorganisms, are important causative agents of
mastitis. The staphylococci exist upon the body surface, in
the alimentary tract and in the general environment of man
and animals. Certain species occur abundantly in air, soil,
water and sewage. Mastitis staphylococci ordinarily are thought
not to possess the invasive powers characteristic of mastitis
streptococci. However, under certain conditions, particularly
where sanitary measures are neglected and environmental con-
ditions are favorable, staphylococci succeed in gaining entrance
to the udder tissues where they often produce the characteristic
symptoms and lesions of mastitis. Staphylococcus aureus is the
species most frequently associated with this form of udder in-
fection. Once this microorganism gains a foothold within the
udder its invasive powers seem to be enhanced. Udders thus
infected ivith staphylococci may serve as foci of infection from
which other cattle may become infected.

PATH OF ENTRY OF THE CAUSATIVE MICROORGANISMS
The causative microorganisms of mastitis that propagate
within infected udders are shed into the milk. These virulent







Florida Agricultural Experiment Station


CAUSES OF MASTITIS

Numerous types of microorganisms, including species of
streptococci, staphylococci, diplococci, coliform and other bac-
teria, either alone or in combination, have been described as the
causative agents of mastitis. While bovine mastitis may result
from infections of the udder with several species of micro-
organisms, the most common infectious types encountered in
the herds under observation are associated with the presence of
streptococci and staphylococci within the udder. In studying
the bacterial flora of the udder during outbreaks of mastitis
occurring over a wide area, Streptococcus agalactiae frequently
was found to be associated with the disease. This streptococcus
primarily is an inhabitant of the mammary glands of cattle.
Environmental conditions within the udder tissues are ideal
for its parasitic existence and propagation. That this micro-
organism is able to maintain and propagate itself within the
udder tissues is demonstrated by its continued presence in the
milk during succeeding lactations. Under natural conditions
S. agalactiae is thought not to exist for great lengths of time
outside the udder tissues.
Species of staphylococci, which are common pus and toxin-
producing microorganisms, are important causative agents of
mastitis. The staphylococci exist upon the body surface, in
the alimentary tract and in the general environment of man
and animals. Certain species occur abundantly in air, soil,
water and sewage. Mastitis staphylococci ordinarily are thought
not to possess the invasive powers characteristic of mastitis
streptococci. However, under certain conditions, particularly
where sanitary measures are neglected and environmental con-
ditions are favorable, staphylococci succeed in gaining entrance
to the udder tissues where they often produce the characteristic
symptoms and lesions of mastitis. Staphylococcus aureus is the
species most frequently associated with this form of udder in-
fection. Once this microorganism gains a foothold within the
udder its invasive powers seem to be enhanced. Udders thus
infected ivith staphylococci may serve as foci of infection from
which other cattle may become infected.

PATH OF ENTRY OF THE CAUSATIVE MICROORGANISMS
The causative microorganisms of mastitis that propagate
within infected udders are shed into the milk. These virulent







Infectious Bovine Mastitis


bacteria are transferred to the teats of susceptible cattle by
various mechanical agencies. Microorganisms which have been
implanted mechanically near the external teat opening gain en-
trance into the cistern of the teat through the streak canal.
Having successfully traversed the natural barrier of the streak
canal with its protecting sphincter muscle, the invading micro-
organisms may propagate and disperse throughout the udder
tissues. All attempts to induce mastitis by introducing the
causative microorganisms into the mouth, eyes and veins, or
beneath the skin, have failed to produce the disease.

MEANS OF TRANSMITTING THE CAUSATIVE
MICROORGANISMS
The virulent bacteria which are present in the udder secre-
tion of infected cows contaminate the teat cups of the milking
machine and the hands of the milker, which aid in disseminating
the disease. While contaminated milking equipment is con-
sidered to be the most important factor in spreading mastitis
infections, all agents and environmental conditions that serve
to implant the virulent microorganisms upon the surface of
the udder must be considered potential factors in the spread of
the disease. Contaminated wash water and soiled wash cloths
used for washing infected udders may serve to implant viru-
lent mastitis bacteria on non-infected udders.
Milk spilled on the floors of the milking sheds, or on the
rear legs of milk cattle, and milk droplets remaining on the
teat opening after milking are attractive to flies. The indis-
criminate feeding habits of these insects make them agents
in transferring bacterial infections from diseased to healthy
udders. Likewise, gnats of the genus Hippelates may assist in
transferring pathogenic microorganisms to healthy udders.
These insects feed upon a wide variety of substances as well as
upon any milk droplets about the teat opening and could bring
in infection from such other sources. The horn fly, Haematobia
spp., by its habit of sucking blood from the tissues of the teats
and adjoining surfaces of the udder of young heifer calves,
produces serious injury to these parts. Many of these heifer
calves whose udders are seriously attacked in their early life
by the horn fly freshen with blind, asymmetrical quarters or
have abnormal udder secretion. Cultures of bacteria obtained
from the lesions on the udders of young calves and from their
udder secretion before and after calving revealed presence of







Infectious Bovine Mastitis


bacteria are transferred to the teats of susceptible cattle by
various mechanical agencies. Microorganisms which have been
implanted mechanically near the external teat opening gain en-
trance into the cistern of the teat through the streak canal.
Having successfully traversed the natural barrier of the streak
canal with its protecting sphincter muscle, the invading micro-
organisms may propagate and disperse throughout the udder
tissues. All attempts to induce mastitis by introducing the
causative microorganisms into the mouth, eyes and veins, or
beneath the skin, have failed to produce the disease.

MEANS OF TRANSMITTING THE CAUSATIVE
MICROORGANISMS
The virulent bacteria which are present in the udder secre-
tion of infected cows contaminate the teat cups of the milking
machine and the hands of the milker, which aid in disseminating
the disease. While contaminated milking equipment is con-
sidered to be the most important factor in spreading mastitis
infections, all agents and environmental conditions that serve
to implant the virulent microorganisms upon the surface of
the udder must be considered potential factors in the spread of
the disease. Contaminated wash water and soiled wash cloths
used for washing infected udders may serve to implant viru-
lent mastitis bacteria on non-infected udders.
Milk spilled on the floors of the milking sheds, or on the
rear legs of milk cattle, and milk droplets remaining on the
teat opening after milking are attractive to flies. The indis-
criminate feeding habits of these insects make them agents
in transferring bacterial infections from diseased to healthy
udders. Likewise, gnats of the genus Hippelates may assist in
transferring pathogenic microorganisms to healthy udders.
These insects feed upon a wide variety of substances as well as
upon any milk droplets about the teat opening and could bring
in infection from such other sources. The horn fly, Haematobia
spp., by its habit of sucking blood from the tissues of the teats
and adjoining surfaces of the udder of young heifer calves,
produces serious injury to these parts. Many of these heifer
calves whose udders are seriously attacked in their early life
by the horn fly freshen with blind, asymmetrical quarters or
have abnormal udder secretion. Cultures of bacteria obtained
from the lesions on the udders of young calves and from their
udder secretion before and after calving revealed presence of







Florida Agricultural Experiment Station


staphylococci and other microorganisms which are known to be
associated with inflamed udders. The habit of nursing among
pen-mates serves to break the natural seal of the teat opening
and is considered to be an important means of infecting the
udders of young heifer calves. The causative microorganisms
gain entrance into the udder through the broken seal of the
teat opening and often remain dormant until the secreting tis-
sues of the.mammary gland become active at the time of fresh-
ening.
SOME FACTORS THAT PREDISPOSE CATTLE
TO MASTITIS
Cattle that harbor mastitis microorganisms within their ud-
ders constitute a dangerous source of infection for healthy
animals in the herd. Unsanitary milking practices, which per-
mit the transfer of pathogenic bacteria from infected animals
to the teats of non-infected cattle, are important predisposing
factors responsible for the spread of mastitis. Failure to segre-
gate diseased cattle and improper sanitation in the milking
technique are commonly observed to be important predisposing
factors in outbreaks of mastitis.
Large pendulous udders and high production seem to predis-
pose cows to this disease. Injuries to the udder, chilling, cow
pox, warts on the teats, chapped teats and insufficiency of the
sphincter muscles of the external teat opening create and con-
stitute conditions favorable to the development of mastitis.
Unclean, muddy pens and night lots serve to contaminate the
udder with microorganisms that are capable of producing mas-
titis. High curbs, rough terrain, loose wire, briars, and other
objects in the environment of dairy cattle often cause injuries
which may lead to udder infections.

COURSE OF THE DISEASE
Infectious mastitis may occur as an acute, chronic or latent
disease. From a clinical standpoint the forms frequently inter-
grade, making it impossible to distinguish definite lines of de-
marcation. Occurrence of acute mastitis in 1 or more animals
of a dairy herd is suggestive evidence that chronic or latent in-
fections of the udder exist in cows which are not suspected of
harboring the causative microorganisms.
The spread of mastitis infections within a dairy herd usually
is a slow and gradual process. The spread may be rapid, how-







Florida Agricultural Experiment Station


staphylococci and other microorganisms which are known to be
associated with inflamed udders. The habit of nursing among
pen-mates serves to break the natural seal of the teat opening
and is considered to be an important means of infecting the
udders of young heifer calves. The causative microorganisms
gain entrance into the udder through the broken seal of the
teat opening and often remain dormant until the secreting tis-
sues of the.mammary gland become active at the time of fresh-
ening.
SOME FACTORS THAT PREDISPOSE CATTLE
TO MASTITIS
Cattle that harbor mastitis microorganisms within their ud-
ders constitute a dangerous source of infection for healthy
animals in the herd. Unsanitary milking practices, which per-
mit the transfer of pathogenic bacteria from infected animals
to the teats of non-infected cattle, are important predisposing
factors responsible for the spread of mastitis. Failure to segre-
gate diseased cattle and improper sanitation in the milking
technique are commonly observed to be important predisposing
factors in outbreaks of mastitis.
Large pendulous udders and high production seem to predis-
pose cows to this disease. Injuries to the udder, chilling, cow
pox, warts on the teats, chapped teats and insufficiency of the
sphincter muscles of the external teat opening create and con-
stitute conditions favorable to the development of mastitis.
Unclean, muddy pens and night lots serve to contaminate the
udder with microorganisms that are capable of producing mas-
titis. High curbs, rough terrain, loose wire, briars, and other
objects in the environment of dairy cattle often cause injuries
which may lead to udder infections.

COURSE OF THE DISEASE
Infectious mastitis may occur as an acute, chronic or latent
disease. From a clinical standpoint the forms frequently inter-
grade, making it impossible to distinguish definite lines of de-
marcation. Occurrence of acute mastitis in 1 or more animals
of a dairy herd is suggestive evidence that chronic or latent in-
fections of the udder exist in cows which are not suspected of
harboring the causative microorganisms.
The spread of mastitis infections within a dairy herd usually
is a slow and gradual process. The spread may be rapid, how-







Infectious Bovine Mastitis


ever, in herds where control measures are grossly neglected.
During the initial stage of invasion of the mammary gland, the
microorganisms, which enter through the external teat opening,
may find lodgment upon the epithelial surface of the lower ud-
der tissues. Here the bacteria often remain localized and un-
detected. Often a balance exists between virulence of the bac-
teria and resistance of the tissues not associated with clinical
evidence of mastitis. Under the influence of various predis-
posing stimuli, perhaps after several lactation periods, or often
without apparent cause, the quiescent bacteria may become
active. The microorganisms then invade the mammary tissues
beyond the point of initial lodgment. The invading bacteria
eventually gain position in the upper glandular tissues where
their destructive action provokes the usual symptoms and lesions
characteristic of the various forms of mastitis.

SYMPTOMS AND LESIONS OF MASTITIS
Acute infectious mastitis is characterized by a rapidly de-
veloping inflammation affecting the tissues in one or more
quarters of the udder. The inflammation is associated with
swelling, redness, pain and disturbed function of the affected
gland. The udder secretion often presents an abnormal physical
appearance resembling serum, whey or pus, and frequently
shows evidence of red blood corpuscles. The presence of abs-
cesses within the udder is not uncommon. The milk flow is
reduced markedly, and affected animals suffer loss of appetite,
have an elevation of body temperature, may become lame due
to joint involvements, and in some instances they may die from
septicemia. Should the symptoms of acute mastitis disappear
without development of blind or non-functioning quarters, a
state of chronic infection usually results.
The chronic form of infectious mastitis is characterized by
presence of fibrous tissue formation and induration of the af-
fected udder tissues. The udder secretion often is thin and
watery in appearance, small in quantity, and may contain vis-
ible particles of flaky material, shreds or precipitated substances.
As a result of the chronic irritation, produced by the invading
bacteria, fibrous tissue gradually replaces the secreting or
glandular tissue of the udder. This results in greatly reduced
milk production.
In the latent form of infectious mastitis the microorganisms
within the udder apparently are in a state of dormancy and







Infectious Bovine Mastitis


ever, in herds where control measures are grossly neglected.
During the initial stage of invasion of the mammary gland, the
microorganisms, which enter through the external teat opening,
may find lodgment upon the epithelial surface of the lower ud-
der tissues. Here the bacteria often remain localized and un-
detected. Often a balance exists between virulence of the bac-
teria and resistance of the tissues not associated with clinical
evidence of mastitis. Under the influence of various predis-
posing stimuli, perhaps after several lactation periods, or often
without apparent cause, the quiescent bacteria may become
active. The microorganisms then invade the mammary tissues
beyond the point of initial lodgment. The invading bacteria
eventually gain position in the upper glandular tissues where
their destructive action provokes the usual symptoms and lesions
characteristic of the various forms of mastitis.

SYMPTOMS AND LESIONS OF MASTITIS
Acute infectious mastitis is characterized by a rapidly de-
veloping inflammation affecting the tissues in one or more
quarters of the udder. The inflammation is associated with
swelling, redness, pain and disturbed function of the affected
gland. The udder secretion often presents an abnormal physical
appearance resembling serum, whey or pus, and frequently
shows evidence of red blood corpuscles. The presence of abs-
cesses within the udder is not uncommon. The milk flow is
reduced markedly, and affected animals suffer loss of appetite,
have an elevation of body temperature, may become lame due
to joint involvements, and in some instances they may die from
septicemia. Should the symptoms of acute mastitis disappear
without development of blind or non-functioning quarters, a
state of chronic infection usually results.
The chronic form of infectious mastitis is characterized by
presence of fibrous tissue formation and induration of the af-
fected udder tissues. The udder secretion often is thin and
watery in appearance, small in quantity, and may contain vis-
ible particles of flaky material, shreds or precipitated substances.
As a result of the chronic irritation, produced by the invading
bacteria, fibrous tissue gradually replaces the secreting or
glandular tissue of the udder. This results in greatly reduced
milk production.
In the latent form of infectious mastitis the microorganisms
within the udder apparently are in a state of dormancy and







10 Florida Agricultural Experiment Station

there exist no clinical manifestations of disease. Such animals
may or may not develop acute or chronic forms of the disease.

DIAGNOSIS OF INFECTED UDDERS
In acute mastitis the characteristic symptoms previously
described will furnish sufficient evidence for a positive diagnosis.
Chronic mastitis often exists in a herd without the owner or
herdsman being aware of its presence. For this reason the
slowly developing chronic form of mastitis may become wide-
spread within the herd before precautionary measures to pre-
vent its spread are given serious consideration. Where 1 or
more cases of acute mastitis occur in a dairy or where the milk
of 1 or more animals assumes an abnormal physical appearance,
careful observations should be made of the entire herd for
evidence of infected udders. Frequent use of the strip cup
before milking is perhaps the most practical and useful method
to detect presence of precipitates, flaky material, blood, whey
and purulent secretion. These are products of inflammation
that appear at various intervals in the milk from actively in-
fected udders.
Extensive use has been made of the bromthymol blue test to
detect mastitis in the field. The principle involved in this test
utilizes the color reaction of the udder secretion when mixed
with measured amounts of the indicator in a glass test tube.
Test cards containing the indicator on specially prepared blotter
paper also are used for the test. The mammary secretion of
cows having badly diseased udders often has an alkaline re-
action to bromthymol blue. This indicator produces a light
green or dark green color in milk so altered from an infected
quarter, but produces a yellowish green or greenish yellow
color in normal milk. The bromthymol test has serious limi-
tations. It is not reliable in detecting apparently healthy car-
riers of mastitis and is of little value in detecting mild infec-
tions. The test may be expected to produce a color reaction
indicative of mastitis in about 65 to 70 percent of the milk
samples from udders producing milk that is abnormal in physical
appearance. The test should not be used during the "drying
off" period or for approximately 15 days following calving, since
false positive reactions are likely to occur at these times.
A diseased udder usually may be identified by examining
it for presence of excessive deposits of fibrous tissue within the
organ. An experienced person may detect these characteristic







Infectious Bovine Mastitis


deposits by careful palpation of the milked out udder. Infected
udders usually contain slight, distinct or marked fibrous tissue
formation, according to the destructive action produced within
the udder by the invading bacteria.
While use of the foregoing diagnostic field tests will detect
many of the badly infected animals that harbor highly virulent
bacteria, they should be supplemented by laboratory examina-
tion of individual milk samples from all cattle in the herd.
Microscopic examinations of stained smears, prepared from
carefully collected and incubated milk samples, are one of the
most practical and efficient laboratory methods of detecting the
causative microorganisms in infected udders. This method of
diagnosis is desirable where a program of eradicating the
disease is undertaken.

CONTROL OF MASTITIS THROUGH SANITATION
A successful program for the control of mastitis must be
based primarily upon a knowledge of the methods by which the
disease spreads. The program involves establishment of milk-
ing practices and herd management methods that prevent spread
of the causative microorganisms from diseased to healthy cattle.
Since an infected cow is a menace to the entire herd, it is ob-
vious that isolation of the diseased animal is important in mas-
titis control. Where possible, infected cattle should be pastured
and handled away from the non-infected animals. Cattle show-
ing abnormal milk secretion, those having a history of past in-
fection, and those found to be infected by diagonistic tests should
be isolated from the main herd. Where isolation is impossible,
the infected animals should remain outside the barn until the
non-infected cows have been milked and released. The infected
cows should be permitted to enter the barn as a group and
milked last.
Mastitis infected animals should be hand milked. If milking
machines are used, a separate unit should be provided for the
infected. group and this machine should not be used to milk
non-infected animals. The regular practice of sanitary methods
of milking is highly beneficial and will, in itself, do much toward
controlling the spread of mastitis infections. The diagonistic
field tests usually employed in most dairies do not detect the
subclinical cases of mastitis in which the milk remains unaltered
in physical appearance. These subclinical types of mastitis can
serve to perpetuate the disease in the herd. This emphasizes







Florida Agricultural Experiment Station


the importance of sanitation in the milking technique to mini-
mize danger of spreading infection by the use of contaminated
milking equipment used on subclinical cases of mastitis.
PREPARING THE UDDER FOR MILKING
Non-infected cattle, as determined by history and various
tests, should be stanchioned as a group and milked first. The
udder should be carefully cleaned before milking. There are
several methods of cleaning the udder, and individual prefer-
ences exist regarding the technique best suited for particular
herds. The most convenient method may not prove to be the
most effective in mastitis control, and dairymen should strive
for results rather than convenience in the milking routine.
Many successful dairymen wash the udder thoroughly with
warm antiseptic chlorine solution, dry it with a clean cloth which
has been wrung out in fresh chlorine solution and apply the
milker immediately. The machine should not remain on the
udder over 3 or 4 minutes. This method of preparation and
milking results in maximum udder health and milk production.
The antiseptic solution and the wash cloths used for cleaning
the udder should be kept clean and changed frequently. The
use of unclean water and unclean wash cloths is to be severely
condemned. Such material often is responsible for a feeling
of false security and accelerates the spread of udder infection.
PRECAUTIONS WITH MILKING MACHINES
In herds where milking is done by machine, care should be
exercised to minimize the danger of spreading infection by
contaminated teat cups. This danger can be minimized by
thoroughly rinsing the teat cups after milking each cow. Dur-
ing the interval that the machine is being changed to the next
animal, the cups should be dipped in a pail of clean water. This
removes most of the milk from the surface of the rubber liners.
Then the cups should be dipped in a pail of clean warm water
containing fresh antiseptic solution. The rinsing water and
antiseptic solution should be changed as often as necessary to
insure cleanliness of the teat cups. Commercial antiseptics,
suitable for rinsing the teat cups, and instructions for their
use, are available to all dairymen.
The milking machine cannot function satisfactorily unless
properly cared for. It should be cleaned thoroughly and steril-
ized after each milking period. Recommendations of the manu-
facturer should be followed regarding the proper vacuum pres-







Infectious Bovine Mastitis


sure to be used and methods of cleaning and sterilizing the
machine. The following procedure covers important points in
sterilizing the teat cup assembly which is essential in mastitis
control.
Immediately after milking, 2 or 3 gallons of clean cold water
are drawn through the teat cups and tube assembly of each
milking unit. The teat cups are alternately raised and lowered
in the rinse water to permit air to pass through. This gives
an air brush effect, dilutes the milk adhering to the surface of
the liners, and permits easier cleaning. Hot water should not
be used for this preliminary rinse. The teat cup assembly is
then dismantled. All parts of the unit which come in contact
with milk are cleaned by using a special brush and hot water
containing a soapless cleaner. The unit is reassembled and
about 3 gallons of hot water at approximately 180 F. are drawn
through the unit. No air is permitted to pass through the cups
during the hot water processing. The teat cups and assembly
tubes then are placed on the solution rack, filled with a weak
lye or other approved antiseptic solution, covered with clean
gauze, and allowed to remain until the next milking period.
An antiseptic lye solution often used for sterilizing the rubber
liners and tubes of the teat cup assembly on the solution rack
is prepared as follows: Dissolve a 13-ounce can of household
lye in a gallon of water. This makes approximately a 10 percent
concentrated stock solution which should be stored in a covered
crock or glass container. Mix 6 ounces of this stock solution
with sufficient water to make a gallon of mixture. This gives
approximately a 0.4 percent solution of lye suitable for filling
the rubber teat cup liners and rubber tubes on the solution rack.
The solution should be used only once.
Before milking the antiseptic solution is drained from the
teat cup and milking tube assembly and the unit rinsed in a
solution containing approximately 200 parts per million of
chlorine. The 0.4 percent lye solution will not harm rubber,
stainless steel pails or teat cups but should not be used for
cleaning aluminum pails or tinned metal parts of milking
machines.
ADDITIONAL PRECAUTIONS
The milker's hands may become contaminated with infected
milk and thus contribute to the spread of mastitis. The danger
of spreading infection by this means may be minimized by
washing the hands with soap and water after milking each







Florida Agricultural Experiment Station


cow. The milker's hands and the cow's udder should be dry
during milking. Wet hand milking and stripping should be
strictly avoided, as these practices are conducive to the spread
of udder infections.
Gradual culling of the infected group of cows should be prac-
ticed. Unprofitable and badly diseased animals should be dis-
posed of by slaughter, except in rare instances where valuable
breeding animals are involved. It is generally safer to milk
the first-calf heifers before the older animals. Frequent use
of the strip cup or other diagonistic test and reasonably prompt
isolation of infected animals will prove valuable in detecting and
preventing the spread of mastitis.
Fly control and cleanliness of the barns, milking sheds and
of the individual animals will prove beneficial as preventive
measures. Dipping the teats in a dilute chlorine solution after
milking serves to remove the milk film and prevent bacterial
growth. The practice of spilling milk upon the floors or upon
the feet and legs of dairy cattle is unsafe. Udder secretion dis-
carded as a result of mastitis infection should be mixed with a
strong disinfectant solution. The rear surface of the body, in-
cluding the buttock, tail, udder and rear legs of lactating cows
should be kept free of filth. Long hair on the udder should be
clipped as a sanitary precaution. The insertion of milking tubes
and dilators into the teat opening should be avoided except when
absolutely necessary and only when
strict surgical cleanliness is ob-
served.
The use of a wash cart, similar
to that shown, containing a strip
cup, teat rinsing cup, timers and
necessary buckets, will aid in es-
tablishing sanitary milking prac-
Fig. 2.--A wash cart helps tices. One bucket contains individ-
keep milking equipment handy
and sanitary. (Courtesy the De ual clean towels in warm chlorine
Laval Separator Company.) solution for wiping the udder, an
empty bucket is provided for the used towels. Clean water and
warm chlorine solution for rinsing the teat cups are available
in the other buckets.
Careful management practices that avoid injuries to the ud-
der aid in preventing mastitis. The pasture and lots should
be cleared of all briars, loose wire, boards, nails, sharp rocks
and similar objects that are likely to produce udder injury.







Infectious Bovine Mastitis


Stagnant pools around the drinking troughs and feed racks
should be drained or filled. Clean, dry, well drained lots and
pens, free of accumulated litter and fecal matter, should be
provided to minimize danger of udder infection from these
sources. Prompt treatment of chapped teats, cow pox, sores,
warts and abrasions of the udder is recommended.
Young dairy animals for herd replacements should be raised
apart from the mature cattle. Nursing among penmates should
be prevented. The purchase of herd replacement animals
should be confined to calves, yearlings or bred heifers. If
necessary to purchase mature cows, they should be isolated until
proven to be free of mastitis.

PENICILLIN AIDS IN MASTITIS CONTROL
In a mastitis control program major emphasis should be di-
rected towards preventing the disease, rather than treating
infected udders. Treatment of infected udders without regard
to proper sanitary preventive measures will, not control the
disease nor result in material benefit to the owner. In herds
where sanitary milking practices and good herd management
methods are employed the treatment of infected udders is a
valuable aid in combatting the disease.
The use of penicillin offers a promising means of treating
most types of mastitis in both lactating and dry udders. When
properly administered, penicillin is non-irritating and non-toxic
for cattle and is effective against both streptococcus and staphy-
lococcus infections. These are distinct advantages that penicillin
possesses over other preparations used in treating mastitis. A
technique of using penicillin which will be of maximum effective-
ness in treating the different types of mastitis that are en-
countered under average field conditions is still under investiga-
tion. The amount of penicillin solution, its concentration, and
frequency of injection to obtain maximum beneficial results
must be determined. In administering treatments, considera-
tion must be given to the severity of the disease, stage of in-
fection, size of the udder, amount of milk produced and type
of microorganism responsible for the infection.
Four or 5 intramammary injections, at 24-hour intervals via
the teat canal, using 25,000 to 100,000 units 6f penicillin dis-
solved in 1 to 2 ounces of sterile distilled water, is recommended
as a basis for treating the average case. Strict surgical clean-
liness is essential in making intramammary injections.







16 Florida Agricultural Experiment Station

The introduction of microorganisms into the udder as a re-
sult of careless technique must be avoided. The use of soiled
syringes, milking tubes or other equipment for purposes of
giving intramammary injections is likely to result in the intro-
duction of pathogenic bacteria which are penicillin-resistant.
Syringes and needles used in preparing penicillin solutions
should be cleaned thoroughly and then sterilized, preferably by
steam pressure, 15 pounds for 20 minutes, or by boiling in a
covered dish for 10 to 15 minutes. All equipment and material
used in making the injections should be sterilized in a like man-
ner. Care should be taken to prevent contamination of the
material and equipment by the hands or other means while
preparing the solutions or while making the injections. The
udder, teats and teat openings should be cleaned thoroughly
before attempting to introduce penicillin solutions.
Due to the technical nature and dangers involved in admin-
istering penicillin, dairymen are advised to employ the services
of their local veterinarian for this purpose.

SUMMARY AND CONCLUSIONS
Infectious bovine mastitis is recognized as the most import-
ant disease confronting the dairy industry.
Infectious mastitis is caused by microorganisms that enter
the udder through the external teat opening.
The infectious microorganisms are shed into the milk of dis-
eased udders and often transferred to non-infected udders by
contaminated milking equipment and other mechanical means.
In a mastitis control program the major emphasis should
be directed toward preventing spread of the disease through
use of necessary precautionary measures.
Sanitary milking practices and good herd management
methods are fundamental and essential in mastitis control and
constitute the only reliable safeguards in maintaining healthy
udders.
Treatment of infected udders by intramammary injections
of penicillin is a valuable aid to the sanitary program in com-
batting most types of mastitis.
A program of sanitation controls the spread of udder infec-
tions, reduces the incidence of inflamed quarters, lowers the
bacterial content of the milk, and maintains productive ability
of valuable dairy cattle.




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