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PubMed1998

Risk factors for lactation mastitis.

The research undertaken in this study utilized a case-control group nested within a prospective cohort which was followed for the first 3 months postpartum. Mothers with mastitis and their controls were requested to complete a self-report questionnaire designed to investigate the association between the potential risk factors, identified from the literature, and lactation mastitis. Logistic regression analyses of the possible risk factors were performed separately for mothers who had not breastfed previously and those mothers who had breastfed at least one infant prior to this lactation. Analysis showed blocked duct(s) and increased levels of stress were the significant predictors for mastitis in mothers who had breastfed a previous infant and blocked duct(s), restriction from a tight bra, attachment difficulties, and nipple pain during a feed were the significant predictors for mastitis in first time breastfeeding mothers.

Adult↗
PubMed2002

Effect of lactation counselling on subclinical mastitis among Bangladeshi women.

Subclinical mastitis, defined as raised milk sodium/potassium (Na/K) in the absence of clinical symptoms, is associated with poor infant weight gain and increased risk of mother-to-child HIV transmission. Similarly to clinical mastitis, subclinical mastitis appears to have multiple causes, one being poor lactation practice. We investigated whether a single session of lactation counselling around the time of delivery could decrease subclinical mastitis among women in rural Bangladesh. The counselling messages included the importance of giving colostrum, exclusive breastfeeding, feeding on demand and how to achieve good positioning and attachment. Women who had delivered prior to our instituting the counselling intervention (mean 1 month) constituted the uncounselled group. At 1 month postpartum, sodium and potassium were measured in spot milk samples from each breast by flame photometry and interleukin-8 (IL8) by ELISA. Geometric mean Na/K ratios and the proportion of milk samples with raised Na/K ratio were significantly (p < 0.05) lower in the counselled group [mean 0.42, 95% confidence interval (CI) 0.39-0.45, n = 116 samples; 10% Na/K ratio > 0.6] than in the non-counselled group [mean 0.49, 95% CI 0.45-0.53, n = 127; 25% Na/K ratio > 0.6]. Milk IL8 concentration did not differ between groups. The results show that among Bangladeshi women a simple lactation counselling intervention could improve lactation practice in ways likely to improve infant health.

Adult↗
PubMed2003

Application of disease-associated differentially expressed genes--mining for functional candidate genes for mastitis resistance in cattle.

In this study the mRNA differential display method was applied to identify mastitis-associated expressed DNA sequences based on different expression patterns in mammary gland samples of non-infected and infected udder quarters of a cow. In total, 704 different cDNA bands were displayed in both udder samples. Five hundred-and-thirty two bands, (75.6%) were differentially displayed. Ninety prominent cDNA bands were isolated, re-amplified, cloned and sequenced resulting in 87 different sequences. Amongst the 19 expressed sequence tags showing a similarity with previously described genes, the majority of these sequences exhibited homology to protein kinase encoding genes (26.3%), to genes involved in the regulation of gene expression (26.3%), to growth and differentiation factor encoding genes (21.0%) and to immune response or inflammation marker encoding genes (21.0%). These sequences were shown to have mastitis-associated expression in the udder samples of animals with and without clinical mastitis by quantitative RT-PCR. They were mapped physically using a bovine-hamster somatic cell hybrid panel and a 5000 rad bovine whole genome radiation hybrid panel. According to their localization in QTL regions based on an established integrated marker/gene-map and their disease-associated expression, four genes (AHCY, PRKDC, HNRPU, OSTF1) were suggested as potentially involved in mastitis defense.

Animals↗
PubMed2002

Occurrence of clinical and sub-clinical mastitis in dairy herds in the West Littoral Region in Uruguay.

Twenty-nine dairy farms were selected to determine the incidence of clinical mastitis, prevalence of sub-clinical mastitis and bacterial aetiology in the West Littoral Region of Uruguay. In samples taken by the owner and frozen at -20 degrees C during a week the incidence rate of clinical mastitis was determined as 1.2 cases per 100 cow-months at risk. Staphylococcus aureus was the most common isolated pathogen in 37.5% of 40 milk samples from clinical cases obtained in 1 month. No bacteria grew in the 32.5% of the total samples. A sub-sample including 1077 dairy cows from randomly selected farms was used to determine the prevalence of sub-clinical mastitis. These samples were taken on one visit to each farm. The prevalence was 52.4% on a cow basis and 26.7% on an udder quarter basis. In 55.1% of the quarters of the selected animals with more than 300,000 cells/ml there was no growth. The isolated pathogens from sub-clinical cases and their relative frequencies were: Staphylococcus aureus 62.8%, Streptococcus agalactiae 11.3%, Enterococcus sp. 8%, coagulase-negative staphylococci 7.4%, Streptococus uberis 6.4%, Streptococcus dysgalactiae 1.8%, Escherichia coli 1.5% and Staphylococcus hyicus coagulase-positive 0.6%.

Animals↗
PubMed2003

Efficacy of targeted 5-day combined parenteral and intramammary treatment of clinical mastitis caused by penicillin-susceptible or penicillin-resistant Staphylococcus aureus.

Combined parenteral and intramammary treatment of mastitis caused by Staphylococcus aureus was compared to parenteral treatment only. Cows with clinical mastitis (166 mastitic quarters) caused by S. aureus treated by veterinarians of the Ambulatory Clinic of the Faculty of Veterinary Medicine during routine farm calls were included. Treatment was based on in vitro susceptibility testing of the bacterial isolate. Procaine penicillin G (86 cases due to beta-lactamase negative strains) or amoxycillin-clavulanic acid (24 cases due to beta-lactamase positive strains) was administered parenterally and intramammarily for 5 days. Efficacy of treatments was assessed 2 and 4 weeks later by physical examination, bacteriological culture, determination of CMT, somatic cell count and NAGase activity in milk. Quarters with growth of S. aureus in at least one post-treatment sample were classified as non-cured. As controls we used 41 clinical mastitis cases caused by penicillin-susceptible S. aureus isolates treated with procaine penicillin G parenterally for 5 days and 15 cases due to penicillin-resistant isolates treated with spiramycin parenterally for 5 days from the same practice area. Bacteriological cure rate after the combination treatment was 75.6% for quarters infected with penicillin-susceptible S. aureus isolates, and 29.2% for quarters infected with penicillin-resistant isolates. Cure rate for quarters treated only parenterally with procaine penicillin G was 56.1% and that for quarters treated with spiramycin 33.3%. The difference in cure rates between mastitis due to penicillin-susceptible and penicillin-resistant S. aureus was highly significant. Combined treatment was superior over systemic treatment only in the beta-lactamase negative group.

Amoxicillin-Potassium Clavulanate Combination↗
PubMed2006

Mastitis and related management factors in certified organic dairy herds in Sweden.

BACKGROUND: Mastitis is one of the major threats to animal health, in organic farming as well as conventional. Preliminary studies of organic dairy herds have indicated better udder health in such herds, as compared to conventional herds. The aim of this paper was to further study mastitis and management related factors in certified organic dairy herds. METHODS: An observational study of 26 certified organic dairy herds in mid-eastern Sweden was conducted during one year. A large-animal practitioner visited the herds three times and clinically examined and sampled cows, and collected information about general health and management routines. Data on milk production and disorders treated by a veterinarian in the 26 herds, as well as in 1102 conventional herds, were retrieved from official records. Multivariable logistic regression was used to assess associations between herd type (organic vs. conventional) and incidence of disorders. RESULTS: The organic herds that took part in the study ranged in size from 12 to 64 cows, in milk production from 3772 to 10,334 kg per cow and year, and in bulk milk somatic cell counts from 83,000 to 280,000 cells/ml. The organic herds were found to have a lower incidence of clinical mastitis, teat injuries, and a lower proportion of cows with a high somatic cell count (as indicated by the UDS, Udder Disease Score) compared to conventional herds. The spectrum of udder pathogenic bacteria was similar to that found in other Swedish studies. Treatment of mastitis was found to be similar to what is practised in conventional herds. Homeopathic remedies were not widely used in the treatment of clinical mastitis.The calves in most of these organic herds suckled their dams for only a few days, which were not considered to substantially affect the udder health. The main management factor that was different from conventional herds was the feeding strategy, where organic herds used a larger share of forage. CONCLUSION: Udder health in Swedish organic herds appears to be better than in conventional herds of comparable size and production. The major difference in management between the two types of farms is the proportion of concentrates fed. The mechanisms explaining the association between intensity of feeding and udder health in dairy cows require further research.

Animal Feed↗
PubMed1992

Conglutinin, mannan-binding protein, and serum amyloid P component concentrations in sera from cows: changes associated with mastitis.

To study the roles of conglutinin (Kg), mannan-binding protein (MBP), and serum amyloid P component (SAP) in the protection of cattle against infections, the concentrations of these proteins in the sera from cows with mastitis were determined by sandwich enzyme-linked immunosorbent assays. The Kg and MBP concentrations in the sera from cows with mastitis were much lower than those from uninfected (or clinically healthy) ones, and increased after recovery. No significant difference in the SAP concentrations was found between healthy and infected cows. With the sera from cows experimentally infected with bovine leukemia virus, the Kg concentrations were also lower than those from uninfected ones, whereas the MBP concentrations were not. From these findings, the Kg concentration is suggested to be serologically a possible indicator for clinical diagnosis of treatment for mastitis although both Kg and MBP concentrations were found to decrease in cows with mastitis and to increase after recovery.

Animals↗
PubMed1993

Characteristics of Staphylococcus aureus isolated from peracute, acute and chronic bovine mastitis.

Fifty-eight Staphylococcus aureus strains isolated from bovine mastitic milk at 27 dairy farms in Japan during the period from November 1988 to May 1989 were examined for their productivity of virulence associated factors. The positive rates of the total isolates for various virulence factors were as follows: toxic shock syndrome toxin-1 (TSST-1, 27.6%), staphylococcal enterotoxins (SEs, 34.5%), alpha-haemolysin (74.1%), beta-haemolysin (65.5%), delta-haemolysin (12.1%), DNase (100%), egg-yolk factor (25.9%), clumping factor (70.7%) and protein A (58.6%). All of S. aureus isolates from peracute mastitis produced TSST-1, SEC, alpha-haemolysin and beta-haemolysin. While none of clumping factor and protein A were detected among peracute isolates, these factors were produced at a relatively high frequency by isolates from chronic mastitis. In coagulase typing, the most predominant type was VI (36.2%), and types IV, V and VIII were not observed. TSST-1 positive isolates showed interesting characteristics which all of the isolates produce both SEC and coagulase type VI but lack egg-yolk factor, clumping factor and protein A except for one isolate. We could infer that TSST-1 and SEC contribute to bovine mastitis, especially to peracute mastitis from the present study.

Acute Disease↗
PubMed2006

[Lactational mastitis and Baby-Friendly Hospital Initiative, Feira de Santana, Bahia, Brazil].

This study aimed to evaluate whether follow-up of breastfeeding mothers at maternity hospitals classified as "Baby-Friendly Hospitals" in Feira de Santana, Bahia, Brazil, was a protective factor against mastitis. This was a cross-sectional study in which 2,543 mothers of infants (< 1 year of age) were selected by simple stratification and interviewed by 104 college students at immunization services. Measures of association (odds ratio, 95%CI) and statistical significance were calculated by the chi-square test and respective p values. Multivariate analysis was performed using the logistic regression model. Women who delivered in "Baby-Friendly Hospitals" had a lower prevalence of lactational mastitis (3.6% vs. 5.3%; OR = 0.68; 95%CI: 0.46-1.01). Additionally, delivery in Baby-Friendly Hospitals (OR = 0.71; 95%CI: 0.48-1.06), absence of nipple fissure (OR = 0.27; 95%CI: 0.19-0.40), and no maternal outdoor work (OR = 0.64; 95%CI: 0.44-0.94) were also associated with a decreased prevalence of lactational mastitis. Prevalence of lactational mastitis was observed to be lower in women delivering in "Baby-Friendly Hospitals" with breastfeeding counseling programs.

Adult↗
PubMed2002

Apoptosis of bovine neutrophils during mastitis experimentally induced with Escherichia coli or endotoxin.

OBJECTIVE: To determine whether apoptosis of neutrophils was accelerated during mastits experimentally induced by use of Escherichia coli or E coli endotoxin and whether differences were apparent in the response to E coli or endotoxin. ANIMALS: 11 healthy lactating Holstein cows. PROCEDURE: Blood samples were collected from cows at various intervals after intramammary inoculation with E coli or endotoxin. Percentage of apoptotic neutrophils detected after in vitro incubation for 3 hours was determined. Fluorescein isothiocyanate-labeled annexin-V in combination with propidium iodide was used to distinguish apoptosis and necrosis of neutrophils. Total and differential circulating leukocyte counts and rectal temperature were determined at the time of collection of blood samples. Milk yield and milk somatic cell counts were determined at the time of milking. RESULTS: Inoculation of endotoxin did not accelerate in vitro induction of neutrophil apoptosis. However, inoculation of E coli increased the percentage of apoptotic neutrophils. At 18 hours after inoculation, 20% of the neutrophils were apoptotic, compared with 5% before inoculation. Milk somatic cell count and rectal temperature increased, milk production and total leukocyte count decreased, and percentage of immature neutrophils increased after inoculation with E coli or endotoxin. However, kinetics of the responses were more rapid, more severe, and of shorter duration during endotoxin-induced mastitis. CONCLUSIONS AND CLINICAL RELEVANCE: In vitro induction of apoptosis of neutrophils was accelerated only during E coli-induced mastitis and not during endotoxin-induced mastitis. Endotoxin inoculation as a model for studying coliform mastitis in dairy cows should be viewed with caution.

Animals↗
PubMed2003

Clinical characteristics, prevalence, influence on sow performance, and assessment of sow-related risk factors for granulomatous mastitis in sows.

OBJECTIVE: To determine the prevalence and clinical appearance of granulomatous mastitis in sows, to identify sow-related risk factors for development of granulomatous mastitis, and to explore the manner in which the disease influences sow performance. ANIMALS: 1,254 sows from 76 herds. PROCEDURE: A clinical examination was performed at time of weaning and 7 days later. In addition, some sows were reexamined at time of weaning in the subsequent lactation. Data were collected on sow performance. RESULTS: At time of weaning, 205 of 1,254 (16%) sows had granulomatous mastitis, and 7 days later, the prevalence was 19%. Variation between herds was large (0 to 50%). In most of the affected sows (156/205 176%]), only 1 mammary gland was affected. Parity, duration of lactation, and number of teat wounds were identified as risk factors for development of the disease. In 264 of 559 (47%) sows (38/104 [37%] mammary glands), a granuloma recurred in the subsequent lactation. Risk for recurrence was related granuloma appearing in multiple form but not to granuloma size. Affected glands were less distended in the subsequent lactation, suggesting lower milk production. Litter size appeared to be negatively affected by the disease. CONCLUSIONS AND CLINICAL RELEVANCE: Granu lomatous mastitis is a common disease in sow herds maintained on straw bedding and in group housing, and it has negative effects on sow productivity. A thorough description of the clinical appearance of the disease and the identification of risk factors should contribute to development of relevant control measures.

Animals↗
PubMed2006

Genetic diversity and antimicrobial susceptibility profiles among mastitis-causing Staphylococcus aureus isolated from bovine milk samples.

OBJECTIVE: To determine whether particular antimicrobial susceptibility profiles of bovine mastitis-causing Staphylococcus aureus isolates were associated with specific S aureus genotypes. SAMPLE POPULATION: 357 S aureus isolates recovered from milk samples submitted for diagnostic bacteriologic testing from 24 dairy herds. PROCEDURES: Antimicrobial susceptibility of S aureus isolates was assessed by determining minimum inhibitory concentrations (MICs) to 14 antimicrobial agents. After digestion of S aureus genomic DNA by SmaI, electrophoretic patterns were obtained via pulsed-field gel electrophoresis (PFGE) and used to classify isolates into types. Gels were analyzed, and data were used to prepare dendrograms. RESULTS: 308 of 357 (86%) S aureus isolates were susceptible to all antimicrobials evaluated. Forty-nine S aureus isolates were resistant to 1 or more antimicrobials; of these isolates, 37 were resistant only to penicillin, 9 were resistant to penicillin and erythromycin, 2 were resistant to tetracycline, and 1 was resistant to erythromycin. Isolates were assigned to 7 PFGE types. An association was found between PFGE type and antimicrobial susceptibility profile. Organisms with resistance to at least one of the tested antimicrobial agents were identified in only 4 of the 7 types of S aureus. CONCLUSIONS AND CLINICAL RELEVANCE: Antimicrobial resistance was uncommon among the mastitis-causing S aureus isolates identified in the milk samples. A limited number of genotypes were associated with mastitis in these herds. Antimicrobial resistance phenotypes were associated with particular S aureus PFGE types; this association may have implications for future treatment and control of S aureus-associated mastitis in cattle.

Animals↗
PubMed2001

Bacteremia associated with naturally occuring acute coliform mastitis in dairy cows.

OBJECTIVE: To determine the incidence of bacteremia in dairy cows with naturally occurring acute coliform mastitis (ACM) with a wide range of disease severity. DESIGN: Cohort study. ANIMALS: 144 dairy cows with ACM from 6 herds. PROCEDURE: Cows were examined at time of identification of ACM (time 0) and classified as having mild, moderate, or severe mastitis on the basis of rectal temperature, hydration status, rumen contraction rate, and attitude. Cows were reexamined at 24 or 48 hours. Bacteriologic culturing of milk and blood (30 ml), CBC, and serum biochemical analysis were performed at each time point. Appropriate samples were obtained at a single point from herdmates without mastitis (controls) that were closely matched for lactation number and days since parturition. Blood culture results were compared among severity groups and controls by use of chi2 tests, as was outcome of an ACM episode for cows grouped by blood bacterial isolates. RESULTS: Bacteria were isolated from 52 blood samples from 46 of 144 (32%) cows with ACM, which was significantly more than control cows (11/156; 7.1%). Group-1 isolates (Escherichia coli, Pasteurella multocida, Mannheimia haemolytica, Klebsiella pneumoniae, Enterobacter agglomerans, and Salmonella enterica serotype Typhimurium) were identified in 20 of 144 (14%) cows with ACM and 0 of 156 control cows. Group-1 isolates were identified in 4.3, 9.1, and 42% of cows classified as having mild, moderate, and severe ACM, respectively. Escherichia coli and K pneumoniae milk and blood isolates obtained from the same cow were of the same genotype. Bacillus spp were identified in 21 of 144 (15%) cows with ACM, which was significantly more than control cows (3/156; 1.9%). Thirty-five percent of cows with a group-1 isolate died during the mastitis episode. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that bacteremia develops in a substantial proportion of cows with ACM. Classification of severity of disease is important for establishment of effective treatment protocols; parenteral antimicrobial treatment may be indicated in cows with ACM.

Acute Disease↗
PubMed2006

Evaluation of the use of an on-farm system for bacteriologic culture of milk from cows with low-grade mastitis.

OBJECTIVE: To determine factors associated with implementation and use of an on-farm system for bacteriologic culture of milk from cows with lowgrade mastitis, including information on how producers used the on-farm bacteriologic culture system to guide antimicrobial selection practices and the resulting impact on patterns of antimicrobial use. DESIGN: Retrospective cohort study. SAMPLE POPULATION: Producers of 81 dairy farms. PROCEDURE: Farms that used an on-farm system for bacteriologic culture of milk from January 2001 to July 2003 were surveyed. RESULTS: Over half of those producers continuing to use the on-farm culture delayed antimicrobial treatment pending results of bacteriologic culture. Most other producers initiated empirical antimicrobial treatment while bacteriologic culture results were pending. Several barriers to the use of an on-farm system were identified. Significant reductions in rates of antimicrobial use were detected when comparing antimicrobial use rates before and during use of the on-farm system. Most producers chose to treat cows with mastitis caused by gram-positive pathogens with antimicrobials, whereas treatment choices for cows with mastitis caused by gram-negative bacteria and in cases in which no growth was detected varied. CONCLUSIONS AND CLINICAL RELEVANCE: Readily available results permit antimicrobial selections to be made on the basis of the causative agent of mastitis. Adoption of an on-farm system for bacteriologic culture of milk may result in significant reductions in the percentage of cows treated with antimicrobials. Decreasing antimicrobial use may have several benefits including preventing unnecessary discarding of milk, decreasing the potential for drug residues in milk, and improving treatment outcomes as a result of targeted treatments.

Animals↗
PubMed1989

Mastitis and toxic shock syndrome.

Toxic shock syndrome (TSS) secondary to mastitis or breast abscess is only seldom described. We report a case of definite TSS due to postpartum staphylococcal mastitis which evolved over a period of 3 weeks to a breast abscess, recurring after 2 months. Only the episode of acute mastitis was complicated with TSS, while Staph. aureus could be isolated during the period of mastitis from milk and during drainage of the second breast abscess.

Abscess↗
PubMed2000

A quantitative approach to classifying Holstein cows based on antibody responsiveness and its relationship to peripartum mastitis occurrence.

A quantitative approach was developed to classify Holstein cows and heifers based on phenotypic variation of serum antibody response and to determine associations with peripartum mastitis. Using an index, 136 cows and heifers were classified into high (Group 1), average (Group 2), or low (Group 3) antibody groups following immunization with ovalbumin at wk -8, -3, and 0 relative to parturition. The ranking of groups based on the quantitative index of serum antibody response to ovalbumin were similar for sera and whey antibody such that Group 1 > Group 2 > Group 3. Animals were also vaccinated with Escherichia coli J5 (Rhône Mérieux, Lenexa, KS) at wk -8 and -3 relative to parturition. The ranking of groups for E. coli J5 was similar to that observed for serum and whey antibody to ovalbumin. Serum and whey IgG1 and IgG2 concentrations were measured at wk 0, 3, and 6 but differences between groups were not significant. There was no occurrence of mastitis for Group 1 animals in two of the herds. In contrast, Group 1 animals from the third herd had the highest occurrence of mastitis; however, these cases all occurred in first-parity heifers. According to pooled data across all herds, Group 3 animals had the highest occurrence of mastitis. Heritability estimates of serum antibody response to ovalbumin varied between 0.32 to 0.64 depending on week relative to parturition. Heritability estimates of serum antibody response to E. coli J5 also varied between 0.13 to 0.88 depending upon week relative to parturition. These results indicate that high peripartum antibody may be beneficial in some herds.

Animals↗
PubMed2002

Relationships among severity and duration of clinical mastitis and sire transmitting abilities for somatic cell score, udder type traits, productive life, and protein yield.

The objective of this study was to determine the relationships among severity and duration of clinical mastitis during first and second lactation and sire transmitting abilities for somatic cell score, udder type traits, productive life, and protein yield. Recording of clinical episodes began at first parturition for 1704 Holstein cows (in six Pennsylvania herds and one Nebraska herd) and continued into second lactation for 1055 of these cows. A total of 456 cows (sired by 168 bulls) had at least one clinical episode during first lactation, and 230 cows (sired by 100 bulls) had at least one clinical episode during second lactation. A severity code from 1 (normal milk) to 5 (acute systemic mastitis) was assigned daily (for up to 30 d after detection) to all quarters that had clinical mastitis. Only the severity codes for the first clinical episode to occur during first and second lactation are considered here. The initial and maximum severity codes, as well as the natural logarithms of both the sum of severity codes that were above normal (> 1) and the total days severity codes were above normal were regressed on herd (a classification variable), age at first calving, days in milk at clinical detection, and sire transmitting abilities taken one at a time. Linear and nonlinear effects were estimated for sire transmitting abilities. Separate analyses were conducted on dependent variables that considered severity and duration of clinical mastitis from: all organisms, coagulase-negative staphylococci, coliform species, streptococci other than Streptococcus agalactiae, and the most common environmental organisms (coliform species and streptococci other than Streptococcus agalactiae). Daughters of sires that transmit the lowest somatic cell score had the least severe and shortest clinical episodes from environmental organisms during first lactation. Selection for lower somatic cell score may reduce the severity and duration of clinical episodes from environmental organisms during first lactation.

Animals↗
PubMed2002

Efficacy of systemic ceftiofur as a therapy for severe clinical mastitis in dairy cattle.

The objectives of this study were to determine the efficacy of intramuscular administration of ceftiofur to reduce the incidence of case-related death and culling following severe clinical mastitis in lactating dairy cattle. A total of 104 cows with severe clinical mastitis (systemic signs) were enrolled in the study and randomly assigned to one of two treatment groups. Immediately after detection of the case, one group was administered 2.2 mg/kg of ceftiofur intramuscularly, and the dose repeated at 24-h intervals for a total of five doses. The second group of cows did not receive systemic antibacterial therapy. Additionally, all cows in both treatment groups received intramammary pirlimycin (Pirsue) in the affected quarter every 24 h for a total of up to three doses. Also at the onset of the case, all cows on the trial were administered a supportive therapeutic regimen of fluids and anti-inflammatory agents that varied from farm to farm, but was standard within each herd at the discretion of the herd manager and veterinarian. Of all cases 14/104 (13.5%) resulted in a lost cow (died or culled). The proportion of cases that resulted in a lost cow and were treated with ceftiofur (4/51; 7.8%) did not statistically differ from cows that were not treated with ceftiofur (10/53; 18.9%). However, the proportion of cases that resulted in lost cows was higher for those cases that yielded a coliform organism on culture (14/56; 25.0%) than cases that did not yield coliforms (0/48; 0.0%; P < 0.001). Thus, among coliform cases, cows that were not treated with ceftiofur were more likely to be culled or die (10/27, 37.0%; P < 0.05) than cows treated with ceftiofur (4/29, 13.8%). We conclude that intramuscular administration of ceftiofur did not affect the outcome of severe clinical mastitis when all etiologic agents are included in the analysis. However, for severe clinical mastitis cases caused by coliform organisms, ceftiofur therapy reduced the proportion of cases that resulted in cow death or culling. This benefit may be realized because of the amelioration of bacteremic-related pathogenesis.

Animals↗