CL Treatments

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    Comparison of three treatment regimens
    for sheep and goats with caseous lymphadenitis


    Kevin E. Washburn, dvm, dacvim, dabvp; Wesley T. Bissett, dvm, phd; Virginia R. Fajt, dvm, phd, dacvcp;
    Melissa C. Libal, dvm, ma, dacvm; Geoffrey T. Fosgate, dvm, phd, dacvpm; Joseph A. Miga; Kristine M. Rockey


    Objective—To compare the effectiveness of 3 treatment regimens for small ruminants with
    caseous lymphadenitis.
    Design—Randomized clinical trial.


    Animals—44 client-owned sheep and goats.
    Procedures—Aspirates were obtained from 48 lesions of 44 enrolled animals and submitted
    for bacterial culture. Animals were randomly assigned to 1 of 3 treatment groups.Treatment
    for group A (n = 15 lesions) consisted of opening, draining, and flushing the lesions
    and SC administration of procaine penicillin G. Treatment for group B (n = 15 lesions) consisted
    of closed-system lavage and intralesional administration of tulathromycin. Treatment
    for group C (n = 18 lesions) consisted of closed-system lavage and SC administration of
    tulathromycin. All animals were reexamined approximately 1 month after treatment, unless
    treatment failure was detected prior to that time.


    Results—43 animals with lesions had positive results (Corynebacterium pseudotuberculosis)
    for bacterial culture. Proportions of lesions that had resolution of infection by 1 month
    after treatment did not differ significantly among the treatment groups (group A, 13/14
    [92.9%]; 95% confidence interval [CI], 69.5% to 99.6%; group B, 10/12 [83.3%]; 95% CI,
    54.9% to 97.1%; and group C, 14/17 [82.4%]; 95% CI, 59.1% to 95.3%).


    Conclusions and Clinical Relevance—Acceptable alternatives to opening, draining, and
    flushing of lesions may exist for treatment of sheep and goats with caseous lymphadenitis.
    Use of tulathromycin and penicillin in this study constituted extralabel drug use, which
    would require extended withholding times before milk or meat of treated sheep and goats
    can be sold for human consumption. (J Am Vet Med Assoc 2009;234:1162–1166)



    Caseous lymphadenitis is a chronic, suppurative disease
    caused by Corynebacterium pseudotuberculosis.
    Sheep, goats, horses, cattle, and humans can be affected
    by this disease. Caseous lymphadenitis is currently of
    most interest in small ruminants and is implicated as the
    third leading cause of economic loss to the sheep industry
    in the western United States.1 In 1 report2 in which
    investigators examined samples from culled sheep from
    regions representing 9 western states, the prevalence was
    estimated as 42.41%. Although prevalence studies for
    goats in the United States are lacking, there is an ever-
    increasing number of goats3 and caseous lymphadenitis
    should be an important health consideration.

    The characteristic lesions of caseous lymphadenitis
    are single or multiple abscesses of the lymph nodes,
    skin, and viscera.4 The causative organism enters the
    body through broken or intact skin, via inhalation, or
    across mucous membranes. Inside the host, the organism
    spreads via the lymphatics to lymph nodes and internal
    organs, where abscesses develop during a period
    of 2 to 6 months. Bacteria are released into the environment
    through discharge from draining superficial

    From the Departments of Large Animal Clinical Sciences (Washburn,
    Bissett), Veterinary Physiology and Pharmacology (Fajt), Veterinary
    Pathobiology (Libal), and Veterinary Integrative Biosciences
    (Fosgate), College of Veterinary Medicine and Biomedical Sciences
    (Miga, Rockey), Texas A&M University, College Station, TX 77843.

    Supported by the American Boer Goat Association.

    Address correspondence to Dr. Washburn.

    Abbreviation

    CI Confidence interval

    abscesses or are aerosolized from ruptured abscesses in
    the lungs.5

    Treatment and control modalities for caseouslymphadenitis include lancing of abscesses and flushing
    with potentiated iodine solutions, treatment with
    antimicrobials, culling of affected animals, surgical removal
    of abscesses, intralesional injection of formalin,
    and isolation from other animals to prevent disease
    spread.6 Lancing and flushing abscesses create a potential
    hazard for spread of purulent material to fomites
    and into the environment during the convalescent period.
    Although antibacterial protocols have been used
    for pharmacologic treatment of animals with caseous
    lymphadenitis,5,7 acceptable efficacy has not been determined
    because the abscesses typically are thickly encapsulated,
    which hinders penetration of antimicrobials.8Additionally, because of the organism’s intracellular location,
    some antimicrobials may not reach efficacious
    intracellular concentrations. At best, clinicians canhope for a reduction in size of the abscess and nonrecurrence
    of the condition. At worst, the abscesses can
    rupture and drain, which spreads organisms into the
    environment and could potentially infect others in the
    herd. Culling of genetically superior animals is often
    not a desirable or economically feasible option; howev


    1162 Scientific Reports JAVMA, Vol 234, No. 9, May 1, 2009


    er, retaining these animals in the herd greatly increases
    the risk of transmission. Although curative in the short
    term, surgical resection of abscesses does not address
    recurrence, requires local or general anesthesia, and is
    a more expensive option than the other reported treatment
    alternatives. Injection of formalin into the lesions
    reportedly is beneficial9; however, a carcass containing
    formalin would be considered adulterated and would
    be unfit for human consumption. The potential for negative
    public perception related to this practice is also a
    problem.

    Tulathromycin, a newly introduced triamilide
    antimicrobial, is a member of a subclass of the macrolide
    family labeled for treatment of cattle and swine
    with undifferentiated respiratory tract disease. It is
    highly lipid soluble and, in cattle, maintains concentrations
    in lung tissue greater than the minimum inhibitory
    concentration (2.0 µg/mL) for the primary
    respiratory pathogens for at least 7 days.10 The long-
    lasting properties and high degree of lipid solubility
    may allow this drug to enter encapsulated abscesses
    and achieve adequate intracellular concentrations.

    The safety of tulathromycin used in an extralabel
    manner was investigated in another study11 conductedby our laboratory group. In that study,11 tulathromycin
    was administered at 25 mg/kg (11.4 mg/lb; 10 times the
    label dosage) to goats to investigate deleterious effects.
    No short-term adverse effects were detected in that
    study. To our knowledge, there have been no reported
    pharmacokinetic studies conducted in sheep or goats.

    The objective of the study reported here was to
    compare the effectiveness of treatments for small ruminants
    with caseous lymphadenitis. Specifically, we
    evaluated the use of opening, flushing, and draining of
    lesions followed by penicillin administration, closed-
    system lavage and intralesional administration of tulathromycin,
    and closed-system lavage and parenteral
    administration of tulathromycin.

    Materials and Methods

    Sample population—Client-owned sheep and goats
    were used in the study. The criterion for enrollment in
    the study was that an animal had a solitary subcutaneous
    mass consistent with an abscess. The same animal could
    be enrolled more than once during the study period when
    a lesion resolved within 1 month after initial treatment
    and a new lesion developed in another location. A case
    was defined as an enrolled study subject whose lesion
    yielded positive results when cultured for C pseudotuberculosis.
    A study subject could also contribute > 1 case
    during the study period when a new lesion developed
    in another location and when that lesion also had positive
    results for culture of C pseudotuberculosis. Owners
    were required to sign a consent form prior to enrollment
    of their animals. The consent form and study were approved
    by the Texas A&M University Clinical Research
    Review Committee.

    Data obtained for all enrolled animals included
    age, sex, breed, number of days the lesion was evident
    (ie, detected by the owners) prior to initial examination
    by the authors, caseous lymphadenitis vaccination status,
    history of caseous lymphadenitis on the farm, and
    recent antimicrobial treatments. Physical examinations

    were performed, and the lesions were described as firm
    or fluctuant, hair or no hair, and draining or not draining.
    All lesions were photographed, and the location of
    each lesion was recorded.

    Isolation and identification of C pseudotuberculosis—
    For all sheep and goats enrolled in the study, each lesion
    was aseptically prepared by clipping the hair from around
    the lesion, scrubbing the area with betadine solution, and
    rinsing with isopropyl alcohol. Each lesion was then aspirated
    with a 16-gauge, 3-cm needle to obtain material for
    bacterial culture. Samples were inoculated onto 5% sheep
    blood agara and MacConkey agara and into tryptose broth.
    The blood agar and tryptose broth were incubated at 37°C
    in 5% carbon dioxide for up to 72 hours. After incubation
    for 24 to 48 hours, tryptose broth was subcultured to 5%
    sheep blood agar and incubated at 37°C in 5% carbon dioxide
    for an additional 24 to 48 hours (total incubation of 72
    hours). Plates containing MacConkey agar were incubated
    at 37°C in air for up to 72 hours. Suspect colonies were subcultured
    for purity and confirmed to be C pseudotuberculosis
    by useofa Corynebacterium identification system.b

    Serum hemolysin–inhibition test—Blood samples
    were obtained from all sheep and goats prior to
    treatment. Blood samples were collected via jugular
    venipuncture and used for serologic testing to determine
    serum hemolysin–inhibition titers. Briefly,
    the hemolysin inhibition titer was determined by the
    synergistic action of Rhodococcus equi and C pseudotuberculosis
    toxins. Establishing the point at which hemolysis
    was inhibited was performed on a blood agar
    plate. Serum samples were placed in 8 wells cut into
    the plate, which contained 8 different serial dilutions
    of hemolytic units.c

    Treatment groups—Sheep and goats were randomly
    assigned to 1 of 3 treatment groups by use of
    a block design. For treatment group A, lesions were
    opened at their most ventral aspect by use of a No. 21
    scalpel blade. An elliptic incision was made to remove
    skin and provide a sufficient opening for drainage. The
    cavity was drained and flushed thoroughly with diluted
    betadine solution. A single dose of procaine penicillin
    G (20,000 U/kg [9,091 U/lb], SC) was administered in
    the neck region. For treatment group B, lesions were
    pierced with a 16-gauge, 3-cm needle and filled with
    saline (0.9% NaCl) solution to break up purulent material.
    The abscess cavity was then treated with distention
    lavage, with saline solution used to remove purulent
    material. A single dose of tulathromycin (2.5 mg/kg

    [1.14 mg/lb]) was injected into the empty abscess cavity
    (ie, intralesional administration). For treatment group
    C, lesions were lavaged with saline solution (similar
    to the procedure for group B) and a single dose of tulathromycin
    (2.5 mg/kg, SC) was administered in the
    neck region. All sheep and goats were scheduled for a
    reexamination at 1 month after treatment.

    Discharge instructions—Sheep and goats were discharged
    to their owners. Discharge instructions included
    information on the withholding period for animals
    because of the extralabel use of tulathromycin (45 days
    for milk and 36 days for meat) and penicillin (5 days
    for milk and 10 days for meat), as recommended by

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    the Food Animal Residue Avoidance Databank.12 Owners
    were also informed that they would be contacted by
    telephone approximately 1 month after the initial treatment
    to obtain additional information. Finally, owners
    were provided with information regarding biosecurity
    and criteria that constituted treatment failure and
    would necessitate reexamination prior to the scheduled
    1-month reexamination.

    Treatment failure was defined as any sheep or goat
    whose lesion enlarged to pretreatment size or larger
    within 10 days after treatment. For case animals in
    groups B and C, treatment failure also included rupture
    and draining of the lesion. Owners were instructed
    that if there was such a treatment failure prior to the
    scheduled 1-month reexamination, they were to return
    the animal to the veterinarian that enrolled it into the
    study.

    Follow-up telephone call—Approximately 1month after initial treatment, owners were contacted by
    telephone by an interviewer who was not aware of treatment
    group assignment. Information gathered included
    whether the lesion had resolved and, if not, whether the
    lesion was larger, smaller, or had ruptured and drained.
    The interviewer also recorded when a new lesion had
    appeared in another location and whether the animal
    had any adverse effects, such as anorexia or lethargy.
    During the telephone conversation, the appointment
    was scheduled for the 1-month reexamination.

    Follow-up examination—Approximately 1-month
    after initial treatment, all sheep and goats enrolled in
    the study were reexamined. At that time, a lesion was
    considered unresolved when it was still evident in the
    same location as that of the initial examination and was
    the same size, larger, or only slightly reduced in size
    (=
    75% of the original size). Unresolved lesions were
    aseptically prepared, and material was aspirated for
    bacterial culture. Unresolved lesions were opened,
    drained, and flushed in accordance with the protocol
    established for group A animals. Although these lesions
    were considered unresolved for their originally
    assigned treatment groups, another follow-up examination
    performed approximately 1 month after the second
    treatment was used to ensure resolution of lesions.

    Statistical analysis—Data were summarized for
    the 3 treatment groups by use of descriptive statistics.
    The Kruskal-Wallis 1-way ANOVA was used to compare
    medians of quantitative data. Categoric variables
    were compared among the 3 treatment groups and on
    the basis of lesion characteristics by use of .
    2 tests and
    Fisher exact tests for pairwise comparisons. Treatment
    effects were evaluated by estimating risk ratios (comparing
    the proportion of treatment successes withineach group) and their corresponding 95% CIs. Sensitivity
    and specificity of the serum hemolysin–inhibition
    test were estimated as the proportion of culture-positive
    and culture-negative animals, respectively, correctly
    identified by the serologic test. Confidence intervals
    were calculated for all proportions, and categoric analyses
    were performed with available software.d Analysesof quantitative variables were performed with another
    program.e All analyses were considered significant at
    values of P < 0.05.

    Results

    Sample population—During approximately 12months, 44 animals (41 goats and 3 sheep) with 48 lesions
    were enrolled in the study. Two goats each represented
    2 cases and 1 goat represented 3 cases because
    they developed lesions in other locations > 1 month
    apart. Eighteen farms from 2 states were represented;
    12 farms each provided > 1 enrolled animal. Fifteen enrolled
    cases were assigned to group A, 15 were assigned
    to group B, and 18 were assigned to group C.

    Animals ranged from 6 to 96 months of age. Ten
    were male and 34 were female. Goat breeds represented
    included Boer (n = 33 goats), La Mancha (3), Nubian
    (2), and mixed-breed goats (3). The 3 sheep were of
    the Suffolk breed. The number of days that the lesion
    was evident (detected by the owners) prior to initial examination
    by the authors ranged from 1 to 100. Seven
    goats had been vaccinatedf against caseous lymphadenitis;
    vaccinations were administered from 6 months to
    1 year before initial examination by the authors. Thirty-
    five sheep and goats originated from farms with a history
    of caseous lymphadenitis. None of the animals had
    received antimicrobial treatment prior to enrollment in
    the study. Signalment and history of caseous lymphadenitis
    did not differ significantly among treatment
    groups (Table 1).

    Initial physical examination of lesions revealed that
    26 were firm and 21 were fluctuant. Thirty-eight lesions
    were covered with hair, and 9 were considered to have
    no hair. Six lesions were draining, and 41 lesions were
    not draining. Physical examination information wasnot available for 1 lesion in a goat. Lavage of the firm
    (ie, nonfluctuant) lesions was not as rewarding for the
    removal of purulent material, compared with removal
    of purulent material in fluctuant lesions, and the typical
    volume of material aspirated and removed from the
    lesions varied widely on the basis of size and maturity
    of the lesions.

    Culture results—Corynebacterium pseudotuberculosis
    was isolated from 43 lesions. Bacteria isolated
    from the remaining 5 lesions included Arcanobacterium
    pyogenes, coagulase-negative Staphylococcus spp, a-hemolytic
    Streptococcus spp, Pseudomonas spp, and Enterococcus
    spp.

    Results for treatment groups—Of the 43 lesions
    that yielded C pseudotuberculosis on bacterial culture,
    14 were assigned to group A, 12 were assigned to group
    B, and 17 were assigned to group C. Examination findings
    of lesions for the 43 culture-positive cases prior to
    treatment did not differ significantly among treatment
    groups (Table 2). No adverse effects were recorded for
    any sheep or goat during the study period. Additionally,
    there were no treatment failures recorded by the owners.
    All 5 lesions that had negative results when cultured
    for C pseudotuberculosis were considered resolved
    at the 1-month reexamination, whereas 37 of 43 (86%)
    culture-positive lesions were considered resolved. Of
    the 6 unresolved cases at the 1-month reexamination,
    1 had been assigned to group A, 2 to group B, and 3 to
    group C. The proportions of resolution at the 1-month
    reexamination for the 43 C pseudotuberculosis–positivelesions were 92.9% (95% CI, 69.5% to 99.6%), 83.3%

    1164 Scientific Reports JAVMA, Vol 234, No. 9, May 1, 2009


    Table 1—Comparisons of quantitative and proportions for categoric variables of sheep and goats with
    caseous lymphadenitis.

    Treatment group*

    P value†

    Variable A(n=15) B(n=15) C(n=18)

    Overall A vs B and C

    SexFemale (No.) 13 11 12 0.411 0.292
    Male (No.) 2 4 6

    BreedBoer goat (No.) 12 10 15 0.499 1.000
    Other goat (No.) 3 3 2 0.726 1.000
    Sheep (No.) 0 2 1 0.317 0.542

    Vaccinated againstcaseouslymphadenitis (No.)

    Yes 2 3 2 0.761 1.000
    No
    1312 16

    History of caseouslymphadenitis onfarm (No.)

    Yes 12 11 12 0.691 0.727

    No
    346
    Age (mo)‡ 16 (8–60) 24 (8–48) 24 (6–96) 0.689 0.398
    No. of days lesion 7 (1–100) 7 (1–30) 10 (4–60) 0.294 0.473

    noticed prior to
    initial examination‡


    *Treatments were as follows: group A, opening, flushing, and draining of lesion followed by SC administration
    of penicillin; group B, closed-system lavage and intralesional administration of tulathromycin; and group
    C, closed-system lavage and parenteral administration of tulathromycin. †P values for categoric variables
    based on comparison of proportions for the variable (eg, female vs male and Boer vs all others) across treatment
    groups. Values were considered significant at P . 0.05. ‡Value reported is median (range).

    n = Number of lesions; there were 48 lesions for 44 sheep and goats enrolled in the study.

    Table 2—Number of findings in sheep and goats with caseous
    lymphadenitis whose lesions yielded Corynebacterium
    pseudotuberculosis during bacterial culture performed prior to
    treatment.

    Treatment group* P value†


    Variable A(n=14) B(n=11)‡ C(n=17) Overall AvsBandC

    Fluctuant 4 5 9 0.386 0.186
    Firm 10 5 8
    No hair 3 4 2 0.301 1.000
    Hair 11 6 15
    Draining 2 2 2 0.894 1.000
    Not draining 12 8 15

    ‡Missing information from 1 animal.
    See Table 1 for remainder of key.
    (95% CI, 54.9% to 97.1%), and 82.4% (59.1% to 95.3%)
    for groups A, B, and C, respectively; these values did
    not differ significantly (P = 0.668) among treatment
    groups. Resolution of lesions did not differ significantly
    on the basis of lesion characteristics for firm (83%) versus
    fluctuant (89%; P = 0.673), hair (85%) versus no
    hair (89%; P = 1.00), or draining (100%) versus not
    draining (83%; P = 0.569).

    Each of the 2 farms that enrolled the most animals
    had at least 1 animal that provided multiple cases. One
    buck from the farm with the highest number of animals
    enrolled was treated 3 times during a 10-month period
    (defined as 3 cases for that goat). Initially, this goat was
    assigned to group C, and the lesion was considered unresolved
    at the 1-month reexamination. At that time, the
    lesion was treated in accordance with the protocol for
    group A, and it subsequently resolved 1 month later. Five
    and 10 months after initial enrollment, the buck devel


    oped lesions in new locations. It was assigned to groups A
    and C, respectively, and for both of those treatments, lesions
    were considered resolved by the 1-month reexamination.
    The farm with the second highest number of enrolled
    animals had 2 does with lesions that were considered resolved
    at 1 month and that subsequently developed new
    lesions 8 months after initial treatment. Both of these
    does were assigned to group A for the original lesions,
    but both were assigned to group C for the lesions that
    subsequently developed in new locations.

    Serum hemolysin–inhibition test—Antibody titers
    against C pseudotuberculosis (as determined by use of the
    serum hemolysin–inhibition test) at initial examination
    ranged from 0 to 1:64. Of the 43 culture-positive lesions,
    35 were in seropositive animals, with titers that ranged
    from 1:4 to 1:64, whereas 8 were in seronegative animals.
    Sensitivity for the serum hemolysin–inhibition test
    was 81% (95% CI, 68% to 91%). For the 5 culture-negative
    lesions, 3 were in seropositive animals and 2 were in
    seronegative animals. Specificity for the serum hemolysin–
    inhibition test was 40% (95% CI, 7% to 82%). Of the
    7 animals vaccinated against caseous lymphadenitis, 6
    were seropositive (titers ranged from 1:4 to 1:64); 2 of the
    6 were culture-negative animals. The remaining vaccinate
    was a culture-positive animal that was seronegative.

    Discussion

    Animals enrolled in the study reported here were
    predominately Boer goats. This breed represents most
    of the goats examined at our hospital. Additionally, this
    study investigated only 1 form of caseous lymphadenitis.
    Diagnostics were not performed to determine whether

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    any enrolled animals had visceral or internal lymph node
    involvement. However, those manifestations of caseous
    lymphadenitis are most often accompanied by a history
    of chronic weight loss, and none of the animals in this
    study had that history. Despite these limitations, it appears
    from our data that intralesional or parenteral treatment
    with tulathromycin after removal of purulent material via
    needle distention lavage may be an acceptable alternative
    to opening, draining, and flushing caseous lymphadenitis
    abscesses coupled with penicillin administration.

    However, the small number of cases in each treatment
    group in this study did not provide the power necessary
    to make conclusive statements of efficacy. Additional
    studies are needed to accurately determine the benefit of
    various protocols for resolution of caseous lymphadenitis.
    Although not significantly different, lesions treated in accordance
    with the protocol for group A had a higher proportion
    of resolution than for groups B and C combined.
    Because of its spectrum of activity against gram-positive
    organisms, administration of penicillin to goats of group
    A could have contributed to the higher proportion of lesions
    that resolved. However, we believe that the benefits
    of not opening these lesions and avoiding spread of bacteria
    into the environment during the convalescent period
    outweighed the small differences in outcome among these
    groups. Thus, we believe that the higher proportion for
    resolution in group A is not clinically important.

    Interestingly, the sensitivity of the serum hemolysin–
    inhibition test at initial examination was lower than that
    reported for animals with naturally developing infections,
    whereas the specificity was higher.13 False-negative results
    could have been attributable to the enrollment of animals
    with chronic, well-encapsulated abscesses that may have
    had low circulating antibody titers. False-positive results
    in this study could have been attributable to internal abscesses
    or exposure of animals to the organism, especially
    on farms that contributed multiple cases and that had limited
    biosecurity prior to participation in our study. Also, 2
    animals were vaccinated and were seropositive, but their
    lesions did not yield C pseudotuberculosis isolates.

    Although no treatment failures were reported by the
    owners, it is possible that lesions opened and drained in
    such a manner that they were not noticed by the owners.
    Nevertheless, there was only 1 new animal that developed a
    lesion among all 18 farms represented during the approximately
    12-month study period, which indicated that once
    affected animals within a herd were identified, enrolled, and
    treated, there was no widespread increase in disease incidence.
    This suggested that biosecurity measures on those
    farms were excellent or lesions that resolved did so in an innocuous
    manner. Similarities in outcome among treatment
    groups could have been attributable to many factors, most
    notably the number of days the lesion was evident before
    initial examination. Additionally, the stage of the lesion at
    initial treatment may have affected outcome. Lesions that
    were draining at the time of initial examination would have
    been more representative of animals in group A (without
    the betadine flush); therefore, draining lesions assigned to
    groups B (n = 2 cases) and C (2) may have resolved because
    they were open and not because of intralesional or parenteral
    administration of tulathromycin.

    It is possible that the physical removal of purulent material
    via lesion distention lavage with saline solution, as
    performed in groups B and C, may have positively influenced
    outcome in these groups. A control group in which

    lesions were emptied by intralesional lavage but were not
    treated by administration of tulathromycin may have been
    an informative addition to the study; however, the willingness
    of clients to participate may have been compromised.

    To our knowledge, minimum inhibitory concentrations
    of tulathromycin against C pseudotuberculosis isolates
    in small ruminants are lacking, as are pharmacokinetic data
    for tulathromycin in goats. Such studies are warranted to
    determine more precisely the pharmacodynamics of tulathromycin
    when used to treat animals with caseous lymphadenitis.
    Other antimicrobials injected intralesionally may also
    be efficacious and should be examined in future studies.

    Overall, it appears that intralesional or parenteral
    administration of tulathromycin may be an acceptable
    alternative to opening, draining, and flushing of caseous
    lymphadenitis lesions. More affected animals from diverse
    geographic areas and longer follow-up periods are needed
    in future studies to investigate the effects of tulathromycin
    treatment for animals with caseous lymphadenitis on the
    management of this disease in goat herds. Additionally, efficacy
    of this treatment for other manifestations of caseous
    lymphadenitis remains to be investigated.

    a.
    BBL, BVA Inc, San Antonio, Tex.
    b.
    API Corynebacterium identification system, BioMerieux Inc, Hazel-
    wood, Mo.
    c.
    Standard operating procedures, No. 0078, Texas Veterinary Medical
    Diagnostic Laboratory, College Station, Tex.
    d.
    Epi Info, version 6.04, CDC, Atlanta, Ga.
    e.
    SPSS for Windows, version 15.0, SPSS Inc, Chicago, Ill.
    f.
    Case-Bac, Colorado Serum Co, Denver, Colo.
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