A multilocation clinical trial in lactating dairy cows affected with clinical mastitis to compare the efficacy of treatment with intramammary infusions of a lincomycin/neomycin combination with an ampicillin/cloxacillin combination

A study was conducted to compare the efficacy in lactating dairy cows of intramammary infusions in quarters affected with clinical mastitis between a formulation containing 330 mg lincomycin and 100 mg neomycin in a 10-mL aqueous solution (LINCOCIN FORTE S, Pharmacia & Upjohn) and a formulation containing 75 mg ampicillin and 200 mg cloxacillin in an oil suspension (AMPICLOX, Pfizer Animal Health). This study was designed as a multicentre clinical trial involving investigators in France, Germany and Belgium and carried out according to the European Commission guidelines on Good Clinical Practices. Cows in the herds were monitored for clinical mastitis. When evidence of clinical mastitis was detected in a single quarter, a pretherapy milk sample was collected from the affected quarter. After milk sampling, the cow was assigned to one of the two treatment groups at random and treated with an intramammary infusion of one syringe of either LINCOCIN FORTE S or AMPICLOX for three successive milkings in the mastitic quarter. At 4-5, 13-15 and 20-22 days after first infusion, the veterinarian returned to the farm to conduct a clinical examination and collect milk samples from the affected quarter. Milk samples were cultured for the presence of mastitis organisms and somatic cell count (SCC) was measured. Following a 10-month study period, 256 cases were enrolled in the study. A total of 232 and 189 cases were analysed for clinical cure and for clinical-plus-bacteriological cure, respectively. The proportions of cases cured clinically and cured clinically-plus-bacteriologically were compared between the two treatment groups. Somatic cell count differences between treatment groups were also tested. The clinical cure rate for LINCOCIN FORTE S (62.5%) was significantly better than for AMPICLOX (51.8%) (P = 0.035). The clinical-plus-bacteriological cure rate was also significantly better for LINCOCIN FORTE S (38.1%) than for AMPICLOX (21.7%) (P = 0.005). Among bacteriologically cured cases, the SCC declined in both treatment groups but the SCC was significantly higher for the AMPICLOX group than for the LINCOCIN FORTE S group (P = 0.036). In conclusion, clinical cure rate, clinical-plus-bacteriological cure rate, and SCC level were significantly better with LINCOCIN FORTE S than for AMPICLOX.     

Intramammary application of ozone therapy to acute clinical mastitis in dairy cows

The infusion of ozone into the inflamed quarter of cows with clinical mastitis was performed and the efficacy of ozone therapy was evaluated. Ozone was infused into the inflamed quarter via a teat canal using ozone gas generating equipment. Nineteen Holstein cows with acute clinical mastitis were divided into two groups: 15 cows treated with ozone therapy, and 4 cows treated with antibiotic therapy. Systemic and local clinical signs, California Mastitis Test scores, the mastitis causing pathogens, electronic conductivity of milk, and somatic cell counts in milk from ozone- and antibiotic-treated quarters, were compared between the groups. Sixty percent (9/15) of cows with acute clinical mastitis treated with ozone therapy, did not require any antibiotics for recovery. This newly developed ozone therapy method was proven to be effective, safe, and cost effective, and carries no risk of drug residues in milk.     

生物氧疗法辅助治疗奶牛临床型乳房炎疗效观察

乳房炎是成年奶牛最常见的一种疾病,发病率可达30%(Gardner等,1990),奶牛生产单位每年因乳房炎导致的淘汰率约10%,占牛群总淘汰率的1/2左右[1].乳房炎可以降低奶牛产奶量(下降10%～15%)、增加医疗费用支出,从而造成严重的经济损失;此外,乳房炎还会降低牛奶品质、造成牛奶的公共卫生安全隐患[1-3].     

中药乳房灌注剂治疗奶牛临床型乳房炎

1 材料与方法1.1 试验动物的选择和分组在黑龙江省某奶牛场选取患临床型乳房炎的奶牛25头,主要表现为:患病乳区奶汁异常(出现絮片、凝块或呈水样),乳房有不同程度的红、肿、热、痛症状,奶产量下降,但无明显的全身症状.分成两组,第一组为中药组15头,共33个患病乳区;第二组为西药对照组10头,共18个患病乳区.     

Evaluation of stratification factors and score-scales in clinical trials of treatment of clinical mastitis in dairy cows

There is often a need to reduce sample size in clinical trials due to practical limitations and ethical considerations. Better comparability between treatment groups by use of stratification in the design, and use of continuous outcome variables in the evaluation of treatment results, are two methods that can be used in order to achieve this. In this paper the choice of stratification factors in trials of clinical mastitis in dairy cows is investigated, and two score-scales for evaluation of clinical mastitis are introduced. The outcome in 57 dairy cows suffering from clinical mastitis and included in a clinical trial comparing homeopathic treatment, placebo and a standard antibiotic treatment is investigated. The strata of various stratification factors are compared across treatments to determine which other factors influence outcome. The two score scales, measuring acute and chronic mastitis symptoms, respectively, are evaluated on their ability to differentiate between patients classified from clinical criteria as responders or non-responders to treatment. Differences were found between the strata of the factors severity of mastitis, lactation number, previous mastitis this lactation and bacteriological findings. These factors influence outcome of treatment and appear relevant as stratification factors in mastitis trials. Both score scales differentiated between responders and non-responders to treatment and were found useful for evaluation of mastitis and mastitis treatment.     

Acute phase proteins in serum and milk from dairy cows with clinical mastitis

The serum concentrations of haptoglobin, serum amyloid A and alpha1 acid glycoprotein were determined in serum collected from healthy dairy cows and cows with clinical mastitis, graded as mild (clots in milk) or moderate (clots in milk and visible signs of inflammation in the mammary gland/s) to assess their relative diagnostic value in detecting the disease. The concentrations of haptoglobin and serum amyloid A were also measured in milk collected from infected and uninfected quarters. The concentrations of haptoglobin and serum amyloid A were higher in the serum and milk from the cows with mild or moderate mastitis. The diagnostic value of haptoglobin in differentiating between healthy animals and those with mastitis gave sensitivities and specificities of 82 per cent and 94 per cent respectively with serum and 86 per cent and 100 per cent with milk. The diagnostic value of serum amyloid A in differentiating between healthy animals and those with mastitis gave sensitivities and specificities of 83 per cent and 90 per cent with serum and 93 per cent and 100 per cent with milk. The diagnostic value of serum alpha1 acid glycoprotein in differentiating between healthy animals and those with mastitis gave sensitivities and specificities of 62 per cent and 91 per cent.     

Prediction of penicillin resistance in Staphylococcus aureus isolates from dairy cows with mastitis,based on prior test results

AIM: To gauge how well prior laboratory test results predict in vitro penicillin resistance of Staphylococcus aureus isolates from dairy cows with mastitis.

METHODS: Population-based data on the farm of origin (n=79), genotype based on pulsed-field gel electrophoresis (PFGE) results, and the penicillin-resistance status of Staph. aureus isolates (n=115) from milk samples collected from dairy cows with mastitis submitted to two diagnostic laboratories over a 6-month period were used. Data were mined stochastically using the all-possible-pairs method, binomial modelling and bootstrap simulation, to test whether prior test results enhance the accuracy of prediction of penicillin resistance on farms.

RESULTS: Of all Staph. aureus isolates tested, 38% were penicillin resistant. A significant aggregation of penicillin-resistance status was evident within farms. The probability of random pairs of isolates from the same farm having the same penicillin-resistance status was 76%, compared with 53% for random pairings of samples across all farms. Thus, the resistance status of randomly selected isolates was 1.43 times more likely to correctly predict the status of other isolates from the same farm than the random population pairwise concordance probability (p=0.011). This effect was likely due to the clonal relationship of isolates within farms, as the predictive fraction attributable to prior test results was close to nil when the effect of within-farm clonal infections was withdrawn from the model.

CONCLUSIONS: Knowledge of the penicillin-resistance status of a prior Staph. aureus isolate significantly enhanced the predictive capability of other isolates from the same farm. In the time and space frame of this study, clinicians using previous information from a farm would have more accurately predicted the penicillin-resistance status of an isolate than they would by chance alone on farms infected with clonal Staph. aureus isolates, but not on farms infected with highly genetically heterogeneous bacterial strains.     

Prediction of penicillin resistance in Staphylococcus aureus isolates from dairy cows with mastitis, based on prior test results

AIM: To gauge how well prior laboratory test results predict in vitro penicillin resistance of Staphylococcus aureus isolates from dairy cows with mastitis. METHODS: Population-based data on the farm of origin (n=79), genotype based on pulsed-field gel electrophoresis (PFGE) results, and the penicillin-resistance status of Staph. aureus isolates (n=115) from milk samples collected from dairy cows with mastitis submitted to two diagnostic laboratories over a 6-month period were used. Data were mined stochastically using the all-possible-pairs method, binomial modelling and bootstrap simulation, to test whether prior test results enhance the accuracy of prediction of penicillin resistance on farms. RESULTS: Of all Staph. aureus isolates tested, 38% were penicillin resistant. A significant aggregation of penicillin-resistance status was evident within farms. The probability of random pairs of isolates from the same farm having the same penicillin-resistance status was 76%, compared with 53% for random pairings of samples across all farms. Thus, the resistance status of randomly selected isolates was 1.43 times more likely to correctly predict the status of other isolates from the same farm than the random population pairwise concordance probability (p=0.011). This effect was likely due to the clonal relationship of isolates within farms, as the predictive fraction attributable to prior test results was close to nil when the effect of within-farm clonal infections was withdrawn from the model. CONCLUSIONS: Knowledge of the penicillin-resistance status of a prior Staph. aureus isolate significantly enhanced the predictive capability of other isolates from the same farm. In the time and space frame of this study, clinicians using previous information from a farm would have more accurately predicted the penicillin-resistance status of an isolate than they would by chance alone on farms infected with clonal Staph. aureus isolates, but not on farms infected with highly genetically heterogeneous bacterial strains.     

Intramuscular treatment of subclinical staphylococcal mastitis in lactating cows with penicillin G, methicillin and their esters

The relationship between antibiotic milk concentrations and bacteriological efficacy was investigated in groups of lactating cows with subclinical mastitis due to either penicillin G-sensitive or penicillin G-resistant Staphylococcus aureus. Treatments consisted of the intramuscular injection of procaine penicillin G, or its weak base ester penethamate hydriodide, and sodium methicillin, or its weak base ester tamethicillin. Antibiotics were administered once daily for 2 or 4 days at accepted dosages. After four daily, treatments with procaine penicillin G and penethamate hydriodide, infections were eliminated from 56.5% and 68.8%, respectively, of quarters infected with penicillin G-sensitive staphylococci, and from 14.3% and 7.7%, respectively, of quarters infected with penicillin G-resistant staphylococci. After four daily treatments with sodium methicillin and tamethicillin, infections were eliminated from 32.4% and 48.6%, respectively, of quarters infected with penicillin G-resistant staphylococci. The better efficacy of penethamate hydriodide and tamethicillin was considered to be linked to the higher milk drug concentrations obtained with these drugs as opposed to the lower concentrations measured in the milk after treatment with the parent drugs. Cure rates were generally higher after treatment for 4 days than after the 2-day course of therapy. Treatment efficacy decreased progressively with increasing age of the cows. Intramuscular treatment of subclinical staphylococcal mastitis in lactating cows can serve as a useful model for screening existing and new antibacterial agents and drug products intended for the parenteral treatment of clinical staphylococcal mastitis.     

Intramammary administration of gentamicin as treatment for experimentally induced Escherichia coli mastitis in cows.

In 8 Holstein cows, 50 colony-forming units (CFU) of Escherichia coli was administered into 1 mammary gland. Infections were established in all inoculated glands. In 4 of the 8 cows, 500 mg of gentamicin sulfate was administered by intramammary infusion 14 hours after inoculation; the other 4 cows were untreated controls. Infusions of gentamicin also were given after each of the 3 successive milkings after the initial infusion, so that a total dose of 2 g of gentamicin was given to each of the treated cows. During the 33-hour treatment period and for the first milking after the last infusion of gentamicin, the treated cows had a mean gentamicin concentration of greater than or equal to 31.0 micrograms/ml in milk samples that were collected from inoculated quarters immediately before each milking. Concentrations of 0.34 and 0.69 micrograms of gentamicin/ml were detected in milk from 2 cows at 8 days after inoculation with E coli. Mean serum concentrations of gentamicin were greater than or equal to 0.37 micrograms/ml throughout the treatment period and the first 12 hours after the last infusion, with a mean peak concentration of 0.96 micrograms/ml at 24.4 hours. The range of peak concentration of gentamicin detected in urine from all treated cows was 42 to 74.4 micrograms/ml. Peak concentration of E coli in milk in the treated cows (6.08 +/- 1.02 log10 CFU/ml) did not significantly (P greater than 0.05) differ from that of the control cows (5.26 +/- 1.00 log10 CFU/ml). Similarly, mean duration of infection in the treated cows (54 hours) did not differ significantly from that of the control cows (48 hours).(ABSTRACT TRUNCATED AT 250 WORDS)     

石河子垦区奶牛临床型乳房炎的发病规律及治疗现状

为了统计和研究石河子垦区大中型奶牛场临床型乳房炎的发病规律及治疗情况,选择石河子垦区6个大中型奶牛场2 600头奶牛作为调查对象,通过对临床型乳房炎进行鉴定及不同治疗方法进行比较。结果表明2 600头奶牛在4—9月份临床型乳房炎发病270头,发病率10.38%;10—3月份发病163头,发病率6.99%。目前在石河子垦区大中型牛场一般常见的治疗药物主要有左旋咪唑拌料、青霉素钾或先锋Ⅴ等＋糖皮质激素、中草药组方和青霉素钾或先锋Ⅴ等＋中草药组方等。结果,经过预防和治疗后,在4—9月份奶牛临床型乳房炎发病率降至4.92%;10—3月份奶牛临床型乳房炎发病率降至3.00%。调查结果表明：中西医结合用药对临床型乳房炎起到了积极的治疗作用。     

Efficacy of intramammary treatment with procaine penicillin G vs. procaine penicillin G plus neomycin in bovine clinical mastitis caused by penicillin-susceptible,gram-positive bacteria--a double blind field study

The efficacy of intramammary treatments containing procaine penicillin G alone (treatment A) or a combination of procaine penicillin G and neomycin (treatment B) was compared in treating clinical bovine mastitis caused by gram-positive bacteria susceptible in vitro to penicillin G. Both treatments were supplemented with a single intramuscular injection of procaine penicillin G on the first day of treatment. The study was carried out using a double blind design on commercial dairy farms in Southern Finland. A total of 56 quarters were treated with treatment A and 61 with treatment B. The cure rates for both treatments were equal, which suggests that the use of the penicillin G-aminoglycoside combination does not increase the efficacy of the treatment over that achieved by using penicillin G alone in bovine clinical mastitis caused by penicillin-susceptible, gram-positive bacteria.     

Prototheca zopfii mastitis in a herd of dairy cows

Mastitis caused by the colourless alga Prototheca zopfii was diagnosed in 17 of 120 cows in a dairy herd. Infection occurred in animals varying from 3-14 years old and was present in one to four quarters of each cow. Nine cases were associated with clinical mastitis characterised by the presence in milk of flakes or small clots. Somatic cell counts consistent with subclinical mastitis (>500 x 10(3) cells/ml) were recorded in five of the eight remaining cows. Histological examination of udder tissue showed the presence of granulomatous lesions associated with the presence of Prototheca. The problem was identified and controlled by repeated microbiological examination of milk samples from all lactating cows and immediate culling of infected animals. P. zopfii was also recovered from environmental water samples on this farm. It is suggested that infection may have occurred as a result of teat sores caused by trauma from a milking machine, and the tendency for cows to lay down on a race, the surface of which was sometimes flooded by drain water in which Prototheca were present.     

Prototheca zopfii mastitis in a herd of dairy cows

Mastitis caused by the colourless alga Prototheca zopfii was diagnosed in 17 of 120 cows in a dairy herd. Infection occurred in animals varying from 3–14 years old and was present in one to four quarters of each cow.

Nine cases were associated with clinical mastitis characterised by the presence in milk of flakes or small clots. Somatic cell counts consistent with subclinical mastitis (>500 × 10³ cells/ml) were recorded in five of the eight remaining cows.

Histological examination of udder tissue showed the presence of granulomatous lesions associated with the presence of Prototheca.

The problem was identified and controlled by repeated microbiological examination of milk samples from all lactating cows and immediate culling of infected animals.

P. zopfii was also recovered from environmental water samples on this farm. It is suggested that infection may have occurred as a result of teat sores caused by trauma from a milking machine, and the tendency for cows to lay down on a race, the surface of which was sometimes flooded by drain water in which Prototheca were present.     

Efficacy assessment of an intramammary treatment with a new recrystallized enrofloxacin vs ceftiofur and parenteral enrofloxacin in dairy cows with nonsevere clinical mastitis

A recrystallized form of enrofloxacin as dehydrate‐HCl (enro‐C) was assessed for bacteriological and clinical cure efficacies in Holstein‐Friesian cows affected of nonsevere clinical mastitis. Treatments were enro‐C_susp (n = 81), treated with a pharmaceutical suspension of enro‐C/quarter; group enro‐C_pd (n = 80) treated as above, but using enro‐C powder suspended in water; group CF (n = 65), treated with ceftiofur HCl/quarter; and group enro_R (n = 66), treated with standard enrofloxacin solution (5 mg/kg, intramuscular). Cows had a mean milk production of 31 L/day and were 2‐3 lactational periods old. Treatments were administered every 24 hr for 3 days. Groups treated with enro‐C exhibited statistically significant (p > .05) better clinical cure as compared to groups treated with CF or enro_R (95.06%, 96.25%, 67.79%, and 57.55%, for enro‐C_susp, enro‐C_pd, CF, and enro_R, respectively). In contrast, probability of bacteriological cure was not statistically different among treatments. Yet, the outstanding clinical and bacteriological cure rates obtained for enro‐C for nonsevere cases of mastitis is superior to previously reported data for parenteral enrofloxacin and other antibacterial‐intramammary treatments. Impact of using enro‐C on the rate and pattern of bacterial resistance, somatic cell counts and milk electric conductivity, must be studied. Also, the use of enro‐C for complicated cases of mastitis should be studied and milk withdrawal times must be accurately established.     

Effects of clinical mastitis and puerperal diseases on reproductive efficiency of dairy cows

Tropical Animal Health and Production - The objective of this study was to evaluate the effects of clinical mastitis (CM) occurring before or after the first AI postpartum, and puerperal diseases...     

Comparison of homeopathy, placebo and antibiotic treatment of clinical mastitis in dairy cows - methodological issues and results from a randomized-clinical trial

Based on the widespread use of homeopathy in treatment of animal disease and the poor documentation of its possible effects and consequences, a clinical trial was carried out in order to evaluate the efficacy of homeopathy in treatment of clinical mastitis in dairy cows and a design for clinical studies on homeopathic treatment, taking into account the guidelines for randomized-clinical trials (RCT) as well as the basic principles of homeopathy. A three-armed, stratified, semi-crossover design comparing homeopathy, placebo and a standardized antibiotic treatment was used. Fifty-seven dairy cows were included. Evaluation was made by two score scales, with score I measuring acute symptoms and score II measuring chronic symptoms, and by recording the frequencies of responders to treatment based on four different responder definitions. Significant reductions in mastitis signs were observed in all treatment groups. Homeopathic treatment was not statistically different from either placebo or antibiotic treatment at day 7 (P = 0.56, P = 0.09) or at day 28 (P = 0.07, P = 0.35). The antibiotic treatment was significantly better than placebo measured by the reduction in score I (P < 0.01). Two-thirds of the cases both in the homeopathy and placebo groups responded clinically within 7 days. The outcome measured by frequencies of responders at day 28 was poor in all treatment groups. Evidence of efficacy of homeopathic treatment beyond placebo was not found in this study, but the design can be useful in subsequent larger trials on individualized homeopathic treatment.     

Fatal mastitis of dairy cows: a retrospective study.

The necropsy records of dairy cows with mastitis were reviewed from the provincial veterinary laboratory in Guelph (44 cases of mastitis in nine years) and from the Ontario Veterinary College (168 cases in 14 years). Mastitis was considered to be the primary cause of death in 167 of 212 cows (79%). Of these 167 cases of mastitis, Escherichia coli was involved in 107 (64%), Klebsiella sp. in 12 (7%) and Staphylococcus aureus in 11 (7%). Bacteriology was not reported in 22 cases. Coliform mastitis, the most commonly identified type of fatal mastitis, was characterized histologically by the presence of infarcted areas in affected glands and by the lack of demonstrable bacteria, and was thus easily identified from fatal mastitis caused by S. aureus.